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Posted by: OU812 Jun 11 2016, 03:59 PM

Did Porsche eff up?

No they didn't eff up, they did the best they could with the new technology they had. It seems as though the technology was purchased by the folks at Bosch from the aviation component of Bendix. That said most Injection systems were originally good at idle and full open throttle, so primarily racing applications. So in there infancy not well suited for automobile applications.

Been reading on different types of fuel delivery systems and their pro and cons.


There are very few con's to todays EFI systems, there were however performance and reliability issues with the original designs. Even today Claims of increased HP, Fuel economy, drivability, reliability and so on....some still dispute
how much these differences really mean. It appears the main thing EFI does extremely well over Carbs is in the pollution factor, or in this case the ability to pollute less. Carbs are a some what open system allowing hydro carbons to escape/vent in to our atmosphere even when the engine is at rest, where as the EFI is essentially a closed system releasing no vapors or gases unless the engine is running and those gases are then coming out of the tailpipe from the exhaust cycle.

Many of the Guru's (about 5 to 1) prefer carburation.

The above Statement isn't correct, although what confuses this OP is the sheer amount of photographic evidence on this site and others including evilbay and CL showing most engine compartments with Carbs installed. Many here have spent thousands on their cars, and what do you see when the lid is lifted? a Carburated engine..... So while my intentions will be keeping my cars in their stock or near stock form, with EFI, I cannot understand why so many Carburated cars. (Because its easy isn't an answer, because its simple isn't an answer and because its cheap isn't an answer)

With this being the case, Did Porsche mess up when they went the EFI route with the 914?


I do not believe they messed up, I believe they did the best they could with the available technology they had. Granted they did sort of use the end user as of a kind of a guinea pig/test bed, but what manufacturer doesn't in some way.

WHY DID THEY DO IT?????


I think that just as much as seeing the Ljet and Djet as a performance and platform to develop future EFI systems off of, Porsche and others also incorporated EFI into there products to show they were progressive company's in design and practicality.
EFI, Unibody, Targa, Mid engine, four wheel disc, and many more attributes can be cited as Porsches View into the future.

I would like to keep my car stock with the factory EFI, but increasingly getting more difficult to do with so little information backing it up.


Above statement is also incorrect. In my case I think I am fortunate because I believe I have most the parts needed to reinstall the factory EFI's on all three of my cars. There is a plethora of info on both sides, but for now.... just for originalities sake, EFI will be the way I go.

To those that added constructive comments and or facts to this thread... it is much appreciated...to those that took this thread as some sort of attack on their beliefs, or way to "clutter" the site, I can appreciate how you feel, but I just see those arguments as shutting down the free flow of ideas and the give and take of facts that get each of us to arrive at our own understanding of the information.

Posted by: Rand Jun 11 2016, 04:11 PM

How many modern cars do you see with carbs? There are reasons they've all gone FI. There's plenty of information to back it up.

Posted by: OU812 Jun 11 2016, 04:23 PM

There is difference between the EFI's of today and the system used on the 914.

Most of what I am reading is saying the Carbs provide a better Low and High speed power band, many go on to say the only spot the EFI is better than the carbs is a small portion of the Mid range.

Posted by: colingreene Jun 11 2016, 04:37 PM

Sure because the EFI was designed to run the motor in a stock or near stock configuration.
When the motor is built to those specs it will run better than it could on carbs.
Carbs are just a easy "Cheapish" way to build a performance motor and get fuel into it.
Really the right way will always be to run electronic fuel injection.
You can do so so so much more and have the car run 1000x times better than you ever could on carbs.
So for the 914 the reason people go to carbs is its cheap and easy compared to re engineering the fuel injection system to properly run a large motor.

Posted by: Rand Jun 11 2016, 04:50 PM

There are too many variables depending on the build of the engine to just give an absolute answer. That's why I was speaking to the technology of carbs vs FI in general.

If you build an engine that gets out of the scope of stock FI, there are programmable aftermarket FI solutions that can match or exceed the performance of carbs while preserving all the benefits of FI.

Posted by: Mueller Jun 11 2016, 05:18 PM

Do you just make shit up? Various books on the older systems, plenty of websites on how they work, people that offer rebuild services and hard parts.

Posted by: ConeDodger Jun 11 2016, 05:44 PM

I'm wondering how old your reference is. Carbs are dinosaurs that will always have a compromise somewhere in their tuning spectrum while EFI is no longer really inflexible and limiting...

Posted by: OU812 Jun 11 2016, 06:17 PM

This is from one of those well respected services you mentioned below.

See all the made up Shit Below

"Will your engine make more peak power with EFI??
More than likely the answer to this is NO. At high RPM and wide open throttle carburetors really work well; so well that it has been hard for us to make more power with EFI on the dyno than a well tuned set of craburetors. The benefits to EFI occur at lower speeds in the form of drive-ability enhancements and torque boosts. This may defy what you've read somewhere else, but it is the fact concerning our own engine program.

Too often people buy into EFI for the wrong reasons, they have a perception that it'll cure all their problems and that it'll be easier to tune and work with than their current Carburetors. I hate to break it to anyone, but if you can't understand or effectively grasp the Carburetor concept enough to tune them you certainly won't be able to work with EFI."

Is it any wonder very few people want to inquire and ask questions here, when you
reply to people in that fashion.

Posted by: Rand Jun 11 2016, 06:21 PM

Like Mueller said, please cite the source. And the build details. Otherwise the quotes are meaningless. (We'll tease him about spelling later. )

Are you talking about your engine, or something non-stock that is purpose built? You have to keep the build in mind when you reply with stuff like this.

Thicken your skin a little if you think this is hard fashion. We are discussing your topic with the interest in getting accurate information to the light.

Posted by: OU812 Jun 11 2016, 06:28 PM

Maybe you should not make such knee jerk reactions accusing people of making shit up.

Asking someone to thicken their skin is BS, it excuses bad behavior.

I would say if you cannot reply and ask for more info instead of making false accusations don't reply at all.

The quote and info on the previous post came from the RABY air cooled technologies site.

I suppose I made that up too.

Posted by: Steve Jun 11 2016, 07:17 PM

Most of us respect Jake. If your building a budget uncomplicated race motor than carbs are nice, but take a look at all the modern race cars. Do you know of any engines running carbs at Lemans this year or any major race? Except maybe redneck nascar.
I never take the advice of one person. I google the question and compare the multiple responses.

Posted by: OU812 Jun 11 2016, 07:20 PM

Thank you for the reply

Posted by: Rand Jun 11 2016, 07:22 PM

What I would value is if we could get on the same page. That's all. Dude, relax a little and get in the vibe we are trying to help you with.

Once again, you are taking things out of context and you have ignored my previous questions. If you want to read them again and offer relevant replies, we'd have something to go on.

Posted by: ClayPerrine Jun 11 2016, 07:24 PM

NASCAR went to Fuel Injection in 2012.

http://www.nascar.com/en_us/news-media/articles/2012/01/11/inside-nascar-fuel-injection-replaces-carburetor.html

Posted by: Zimms Jun 11 2016, 07:34 PM

Jake's comment is based on running at the max. His statement that you posted above even states that EFI is better at low end / regular driving conditions.

I think the biggest confusion is how you started this topic. Looking at two 40+ year old systems you are going to find some +'s and -'s. Current EFI tech in the last 10 years has made it much more common place. Cheaper than a set of carbs? No. Better performance? 100%, unless you are Jake, who can tune a carb in his sleep.

Did Porsche eff up? Everybody starts somewhere, and the technology available for EFI then versus now is a whole different world. Look up when they started to develop their PDK that everyone raves about now. 1986 Derek Bell that almost lost the championship hated it. 2015 Derek Bell has a different impression:

http://www.automobilemag.com/news/derek-bell-pdk-interview/

Technology is a bitch.

Posted by: McMark Jun 11 2016, 07:38 PM

Not sure where you got that info.

IMHO, carbs and FI are just different ways of getting fuel into a motor. FI offers a level of resolution that is impossible with carbs, but they're still just adding fuel to air. All things being equal, they're about the same from a performance standpoint. Any guru that doesn't know the value of either option isn't much of an expert.

Did Porsche screw up? No. FI works fantastic.

Posted by: Steve Jun 11 2016, 07:43 PM

Thanks Clay!! I thought so, but wasn't going to take a chance in my response. Pretty sad that it took them until 2012 to switch to fuel injection.
I put a Weber on my 75 sirocco back in 76 and then dual webers on my 2.4 liter 1971 914-4 back in 1980 and then dual webers on my 2.7 six in my current 1975 914 back in 1986. For that last 16 years I have been running a stock 3.2 in the same 914 with the stock fuel injection. Lots of pros and cons, but I would never switch back to carbs

Posted by: Amphicar770 Jun 11 2016, 08:00 PM

Who are these gurus you are referring to?

Open up Hot Rod or any other performance car magazine. Unless originality is desired, even the owners of old Detroit iron are ditching their carbs for EFI systems to gain both performance and reliability.

While the d-jet system has its shortcomings, carbs are dinosaur technology.

Perhaps one day someone will offer a more modern, plug and play EFI for the 914 but even in today's world I have to wonder who the 4 out of 5 gurus you refer to are?

Posted by: Rand Jun 11 2016, 08:12 PM

If you enjoy touching your starter in any weather condition and your motor purrs to life with a nice idle, and you can start driving any time after. You have FI.

If you enjoy being able to drive in different elevations and your car behaves the same. You have FI.

The thing is, you're all over the map. You have a stock engine with FI, you are quoting Raby builds, and you are spewing irrelevant information with no substance about all the questions we ask about your application.

Be straight. Do you want results from a particular build? Otherwise, I guess I'll enjoy the drama with you.

Posted by: Mueller Jun 11 2016, 08:12 PM

See what I highlighted?
That is what why the factory used EFI. The fuel injection evolved through the years and what company doesn't want to be with the times?

They didn't build the /4 cars for max performance to be held at WOT for peak power. I'm sure the race cars used carbs, and those that didn't use carbs (the sixes and bigger engines used mechanical fuel injection which is too expensive and complicated for a street car sold to the general public.)

They could have easily done the carb thing with a more aggressive cam but they wanted to build daily drivers. (I think they offered dual single throat carbs on the 1.8s in Europe, might be the setup like the 1.8 in the classifieds right now)

Your post comes across as if attacking Porsche for using fuel injection which leads me to believe you are biased against it so no matter what I or anyone else writes you still won't like it and you'll still think Porsche compromised and made a mistake.

Yes, many cars had been converted to carbs by shops and owners, some due to needing the carbs due to modifications, others due to being more familiar with carbs (nothing wrong with that, I took the D-Jet off of an older 2.0 914 I had and replaced it with L-Jet because I know and like it better)

Did Porsche make a mistake by ditching bias ply tires for radials?

Posted by: RacingDreamz Jun 11 2016, 08:12 PM

Hell, I just want my EFI to work so I can start the damn car...

Posted by: stugray Jun 11 2016, 08:24 PM

You can have vastly different levels of tunability even in two "modern" EFI systems.

My son has a 2002 Honda S2000. If he wants to get a new header, or a turbo he is SOL because you cannot "tune" the EFI even in a car that modern.

My 2013 BRZ (with port AND Direct Injection) is about the most advanced you cen get in a car under about $100k and is completely user tuneable.
I can hook a laptop or a tablet to the OBDI port and tune the car myself from the stock 200 HP to almost 1000 hp with bolt on upgrades.

Not all EFIs are created equal.

The most major drawback to the stock EFI on the 914 was that it is an analog computer and cannot be reprogrammed or even modified by normal people.
(Some EEs would have a problem with it today - remember the move Space Cowboys?)

Posted by: Mueller Jun 11 2016, 08:38 PM

The lack of being able to modify doesn't make it a bad system.

I'm sure if Bosch wanted to and felt it a selling point they could have made the FI more apt for modifications.

I'm sure Honda had their reasons as well for locking it down as hard as they have.

Speaking of the BRZ fuel injection...wonder if any of the tweakable Subaru EFI systems can easily be adapted to a 914 /4 motor?

Posted by: zipedadoo Jun 11 2016, 09:02 PM

Another plus is that a modern fuel injection/computer controlled engine is able to run a higher compression ratio, enabling it to make more power and get better fuel economy than the older FI systems or carburetors.

Posted by: r_towle Jun 11 2016, 09:12 PM

Stop being so arguementative with every thread.
Start using search right here.

If we were in a bar or garage talking about cars and shooting the shit, would you start every conversation looking for a fight?

Why do that here?
Of all the topics that have been covered the most, cArbs versus EFI is the best documented and completely explained, yet you feel the need to stir up yet more drama....why?

Posted by: Mueller Jun 11 2016, 09:15 PM

Nothing wrong comparing carbs with EFI, however he basically calling Porsche idiots for using EFI and not sticking with carbs.

Posted by: 914_teener Jun 11 2016, 10:00 PM

Why the voyeuristic drama?

Work on your three cars and share your experiences.

Posted by: Jason74914 Jun 11 2016, 10:17 PM

I also think there is some merit/value to keeping a car original.

Also, in addition to my FI 914, I own carb'd classics and when you look at the Summit Racing or Jegs catalogs, its ironic how much Holley, MSD and Edelbrock,etc are pushing carb owners (and charging big $$) to convert to an "EFI Carb Systems" they sell. Even they see the benefits and the future of their core business.

"Take a technological leap forward with a new electronic fuel injection system from Summit Racing." source link below

Just saying.
Jason

https://www.summitracing.com/search/department/air-fuel-delivery/section/fuel-injection/part-type/fuel-injection-systems?N=4294951509%2B4294930106%2B4294925975&SortBy=Default&SortOrder=Ascending

Posted by: Steve Pratel Jun 11 2016, 11:03 PM

How old are you? If youre not like 16 dude, you are acting like total troll. Have since your first post. If you spend 5 minutes in this or any classic porsche forum, FI is the way most want and encourage people to go. Why did they do it? What a stupid question. FI was and is the best way to fuel an internal combustion engine used in daily/street driving. Hey pal, wake up call. YOUR CAR IS 40 YEARS OLD...... stuff breaks...

Posted by: falcor75 Jun 12 2016, 12:03 AM

Just a tip for anyone wanting to go modern EFI instead if Djet är carbs.

http://www.thedubshop.net/#!blog/cxv7

Newly developed Megasquirt based ECU made for aircooled four cylinder engines.
If I wasnt already invested in another brand this is what I would buy today.

Posted by: OU812 Jun 12 2016, 03:10 AM

Thank you for the information

Posted by: Racer Chris Jun 12 2016, 03:49 AM

It appears that you've misinterpreted the quote from the Aircooled Technologies site.
It doesn't say carbs are better than FI.

It says its hard to beat carbs for making peak power at wide open throttle.
How much time do you spend driving your car at wide open throttle?

It says FI is better for torque (acceleration) and driveability.
To me that sounds like an endorsement for FI in a street car.

I highlighted one sentence to point out that the information presented is specifically targeted to potential customers of the Aircooled Technologies Type 4 engine program.
It would be a mistake to assume this is general knowledge to be applied in any circumstance.

BTW, I have a customer's car in my shop right now that has a Raby built T4 engine, delivered with an aftermarket EFI system installed - not carbs.

Posted by: somd914 Jun 12 2016, 05:31 AM

In respect to increasing displacement and power on a Type IV, sure carbs are the way to go see D-Jet is not tunable, with the exception of some minor tweaks.

But carbs have their flat spots, need routine tweaking, easily clog jets/passageways, etc. For a car I drive a few thousand miles a years and is a hobby for me, I don't mind tweaking carbs. If it were my DD, I'd stick with D-Jet.

But did Porsche (Bosch) screw up? As with almost question of the sort, it's a matter of opinion, but in my mind given the technology then, it was a big step forward.

And as others have mentioned, modern EFI with all of its feedback is awesome (I can swap tunes in my Suby in minutes based on desired driving style for the day). Granted, we are not talking D-Jet, that's where the early FI systems lead to.

If you are worried about originality, obviously stick with D-Jet. If you want to build the engine, i.e. increased displacement and power, you are pretty much limited to carbs or aftermarket EFI.

Posted by: barefoot Jun 12 2016, 07:08 AM

The EFI D-jet system first used on our 914's was standard in VW s type 4's in 1968 and was incorporated to meet emissions req'ts.
As manufactures of injectors for gas turbines, we were working with the Bendix co. Back then and had developed some of our own solenoid controlled injectors. That company did not have great commercial success but licensed Bosch for their patents and they then did very well commercially.
I had some of my own injectors in my 914 for a while as part of our modest test program at Parker.

Posted by: era vulgaris Jun 12 2016, 07:59 AM

Jesus dude, OU812, chill out man. You remind me of a guy I used to know who would do too much coke and argue any and every point he could just to argue!

FI is better. This from an owner of a 2270 with dual DRLA40'S. I'm sick to death of waiting for my carbs to warm up so I can drive, and I'm seriously contemplating selling my car because of it, and taking a reduction in HP to find a stock djet car. I just want to be able to turn the key and drive. No, I don't think Porsche screwed up at all.

Posted by: DBCooper Jun 12 2016, 08:33 AM

To me the question itself, "Why EFI? Why did they do it?, Did someone mess up?" is so silly that it indicates a lack of familiarity with either, carbs or fuel injection.

Posted by: Mueller Jun 12 2016, 09:25 AM

Porsche had how many engineers back in the day? To think one or 2 people made that decision is silly.

If the FI was really that bad would we have as many running fuel injected 914's still running 40 years later? Of course the number get smaller due to one reason or another but it is not because the fuel injection was bad or flawed.

Posted by: Bleyseng Jun 12 2016, 09:40 AM

The MPS is quite tuneable but you just have to learn how to do it.

Posted by: SirAndy Jun 12 2016, 09:54 AM

You need to find better "Gurus" ...

Posted by: Mark Henry Jun 12 2016, 10:05 AM

Lots of experience here and I can make both systems work well.
I can make carbs purr like kitten, but they will never work better overall than FI.


Porsche had to build consumer engines with a high degree of reliability, so yes they left a lot of HP on the table. Really this is no surprise that they do this as every single manufacturer does this.
Engines must start in all kinds of weather, FI adapts to conditions, altitudes, g-forces, be fuel efficient, etc.

In WW2 the benefits of FI were evident, Spitfires couldn't pull negative G's, the pilot had to flip the plane. In a dogfight it was no problem for a ace, but many novices died from this issue. The 109 pilots didn't have to worry about carbs.

Early systems had little wiggle room for performance and most wrenches had little knowledge on how FI worked so carbs were an easy off the shelf solution. Because carbs worked so well, most wrenches got lazy and didn't even want to know about the basics of FI, even how to service a stock system.
Mostly do to the advent of personal computers, by the mid 90's we began to see programmable EFI and the shift slowly began as wrenches became more tech savvy.

One thing as a builder that has always made me laugh is peeps so obsessed with peek HP numbers. To me the number is irrelevant for many reasons, foremost being the dyno operator and what correction factors he arbitrarily decides to use.
In a street car I don't give a poop what you claim your HP numbers are, torque is king.

Posted by: Mueller Jun 12 2016, 10:25 AM

Give him time, he'll find a guru saying carbs create more torque over EFI

Posted by: moorepower Jun 12 2016, 10:31 AM

Carburetor = controlled fuel leak.

Posted by: JmuRiz Jun 12 2016, 11:37 AM

https://m.youtube.com/watch?v=2sQJPZYSoUI

Even a self learning EFI needs more tuning to beat a tuned carb (on the dyno)
Even these guys couldn't deny the EFI advantages.

If I could get ITB EFI for the price of my good webers, i'd trade in a second.

Posted by: OU812 Jun 12 2016, 12:05 PM

Thank for the response Mark Henry.

Your reply along with a few others is all I was looking for, not asking the question because I already Know, Not asking because I am trying to create drama, Not asking to make things up.

On my first car I am thinking which way to go, I have the complete EFI for the engine, and I do have a complete solex setup as well, Being I am more inclined with carbs than EFI and I plan on doing the work myself, I wanted some opinions on which was "Better" before I have to spend more $'s to go the EFI route.

The question was did Porsche eff up, in other words did they mess up by putting on a EFI when the a Carb setup may have been better (didn't some of the European models come with carbs stock?)......Nothing more nothing less.

I have rebuilt many carbs set many float levels replaced many jets. so while not carb expert as many are here, I know enough to where I can make it work. The EFI on the other hand I have very little practical knowledge with this type of system.

Perhaps that is why I asked the question I did.

What I cannot understand is why I get all the smart ass comments, and PM's (you know who you are) telling me to back off on a specific subject matter, or that im giving to much time to a specific subject, and I need to stop.

So instead of jumping on my and others cases and making all kinds assumptions as to my age, whether or not I'm a Trol (not sure what that means), or whether I'm making something up, the thickness of my skin, etc., you could have replied like Mr Henry and the few others that did. With a common sense approach and answers to both type systems.

If my skin was so thin I would not reply at all......this is just as much my forum as it is yours. if you don't like the topic don't respond, Pretty easy.

In closing, I believe if you were to reread this entire thread you would answer the question posed by another members thread wanting to know where all the female members went. Many times women are Much smarter than Men, they wont hang around a site, where they know if they ask a question, rather than getting multiple answers and ideas, they get questions related to their character.

Thank you

Posted by: Mueller Jun 12 2016, 12:14 PM

It is they way you ask...or at least perceived by others.

Again, the asking if Porsche screwed up makes 0 sense and makes it look like you are trying to pick a fight.

There was no massive recalls or problems like when Chevy converted a gas motor to diesel (or Olds I guess) or when Chevy introduced the Vega with an aluminum block with no coatings on the cylinder walls. So yes, Chevy messed up.

Posted by: RacingDreamz Jun 12 2016, 12:33 PM

I have a stock EFI we're thinking of selling or trading. If interested in trading your 2270, let me know.

Posted by: Amphicar770 Jun 12 2016, 12:47 PM

Wow. OP needs to get over himself.

You made a bold assertion backed up by the thinnest of "facts". Most everyone disagreed with you so you react like an angry, drunken "truther". When you have dug yourself into a hole, the first key to getting out is to stop digging. Let it go and move on with life. If you really want to put a carb on you car then go ahead, no one really cares.

Posted by: 914_teener Jun 12 2016, 12:51 PM

In Internet slang, a troll (/ˈtroʊl/, /ˈtrɒl/) is a person who sows discord on the Internet by starting arguments or upsetting people, by posting inflammatory, extraneous, or off-topic messages in an online community (such as a newsgroup, forum, chat room, or blog) with the deliberate intent of provoking readers into ...

I Goggled this....pasted it above.


I order to get replies....the WAY your posts read speak to this, in my humble opinion. Maybe it doesn't bother others. I'm somewhat ambivalent. I can always put your posts on ignore.

Glad that you know how to work on carbs. If you decided that you want to learn about D-jet this place is a great place to learn, and if you want to put carbs on a Type IV there are quite a few folks here that also know a lot about carbs too.

I try to let information inform ME as to my decisions I make....not the other way around.

Posted by: gereed75 Jun 12 2016, 02:14 PM

OU, reread your first post that starts with "why did they do it?? did some one mess up" and then adds ....WHY DID THEY DO IT?????

Oh the horror!!! Why oh why did they do it??

Everyone knows they did it because EFI was the emerging state of the art and met the emissions requirements where carbs had no chance. For all these reasons it was "better".

Did it make more horsepower?..no. They werent concerned with that.

Is it the best for you??...who knows.

But it was certainly not a screw up and to even suggest it was a bit absurd.

That is what got the conversation off into the weeds.

By the way, even though I really like to hear the great noises that come from my triple weber set up (and think the popping, sniffing and wailing is certainly part of the allure of the early air-cooled sixes), I am working to finish an EFI/ITB set up so I can see just how great of a motor an early six can be when it is really optimized - with modern EFI and spark management. Just like Jake did when he was really trying to optimize a Type IV and the customer was willing to pay for it.

I would not bother putting on D-Jet, or even CIS. They were both somewhat lethargic induction systems and compromises limited by the technology of the times, but screw ups?? C'mon

So if you want a somewhat tempermental motor that will probably have snappier throttle response and maybe make a few more HP, go with carbs (and the right cam). If you want a smoother more efficient and gentile motor, and like originality, go stock injection. Your choice, neither is a "screw up".

Posted by: OU812 Jun 12 2016, 02:16 PM

There you go again...............

When you have to call people names and bring there Character into question, it proves you have no argument.

Its obvious there are some that understood my question and replied in kind.

I cannot help it if you and some others want to read something sinister into it.

Like I said before if you don't like the way I pose a question or start a post, you don't need to comment.

Buy the way I saw a nice Amplicar on Lake Minnetonka today, he was just driving down the landing ramp at Lord Fletcher's we watched it launch. Wasn't able to get very close but it looked like a 10+

Posted by: OU812 Jun 12 2016, 02:31 PM

Didn't all of the query's end in question marks?

Seriously I don't know enough to make a blanket statement like that.

But certainly car companies do screw up....and I was simply asking if Porsche did with 914 by going with the EFI instead of carbs?

Shows you how much I have yet to learn, but didn't most if not all the sixes,911's and 912's come with carbs? If EFI was so great back then why wouldn't they have installed EFI on its whole model line?

Just so no one gets there nuts in a sack, please notice all the statements above are Questions and not statements of fact.

Posted by: gereed75 Jun 12 2016, 02:47 PM

Didn't all of the query's end in question marks?

Seriously I don't know enough to make a blanket statement like that.

But certainly car companies do screw up....and I was simply asking if Porsche did with 914 by going with the EFI instead of carbs? [/quote]


Short answer,..... no, not even close


Shows you how much I have yet to learn, but didn't most if not all the sixes,911's and 912's come with carbs? If EFI was so great back then why wouldn't they have installed EFI on its whole model line?



Carbs were gone for FI by 1970 except in the six (only because they had 1969 911 motors to get rid of) and all electronic by 1973.5 (except in the "high performance/track" 911 that still got MFI). Early EFI was not great but no where near a mistake.




Just so no one gets there nuts in a sack, please notice all the statements above are Questions and not statements of fact.
[/quote]

Posted by: The Cabinetmaker Jun 12 2016, 02:55 PM

"Like I said before if you don't like the way I pose a question or start a post, you don't need to comment. "

Like you said before, we all have an equal right to post what we feel here, and the admin have a right and duty to delete when it gets out of hand.

I'm wondering if you might be boning up for a debate team meet.

Posted by: gereed75 Jun 12 2016, 02:59 PM

Is there a "still digging" emoticon??

Posted by: ConeDodger Jun 12 2016, 03:34 PM

You're looking at the wrong information.

By the way, the guy you're arguing with so vehemently? He works in a top secret government project laboratory. You're in over your head... Sorry.

Posted by: Steve Pratel Jun 12 2016, 05:56 PM

Yes ladies and gentlemen, we have a in our midst. This guy ping'd the Troll meter on his first post. Confirmed here. I wont give it the dignity or a response other than

Posted by: bandjoey Jun 12 2016, 06:03 PM

Posted by: OU812 Jun 12 2016, 06:20 PM

Thanks

Posted by: The Cabinetmaker Jun 12 2016, 06:20 PM

"I would like to keep my car stock with the factory EFI, but increasingly getting more difficult to do with so little information backing it up.

Seriously? No information? Have you tried a search here on djet? There are days worth of reading on the subject.

Posted by: OU812 Jun 12 2016, 06:23 PM

And your a senior Member? Must have some erectile dysfunction issues...

Posted by: OU812 Jun 12 2016, 06:24 PM

He,he,he,he

Posted by: 396 Jun 12 2016, 07:08 PM

Oh no, another senseless tread from the expert that joined in 2016.

Posted by: Amphicar770 Jun 12 2016, 07:10 PM

Oh, OU812. As the judge probably told you when he issued a restraining order on behalf of your ex ....

Posted by: OU812 Jun 12 2016, 07:12 PM

I feel like Trump

Posted by: Amphicar770 Jun 12 2016, 07:17 PM

Now that was actually humorous!

Posted by: OU812 Jun 12 2016, 07:18 PM

Must be a senior member thing....never proclaimed that I was a expert, I'm not, that much is clear.

I admit it.....

Although I got a lot of useful info from some of the group so I guess I got that going for me.

Posted by: ConeDodger Jun 12 2016, 09:22 PM

*you're*

Posted by: 914Mike Jun 12 2016, 09:48 PM

Which is why I no longer have any fun in an ICE car. Hasta be electric, where the torque maxes out a zero RPM...

Posted by: theleschyouknow Jun 12 2016, 10:06 PM

fixed it for ya
you catch more flies with sugar than with vinegar


cjl

Posted by: JamesM Jun 12 2016, 10:16 PM

They may "prefer" carbs but it doesn't make them better. Most likely they are preferred because old schoolers understand them and they are easier to work on and tune performance mods around.

Porsche did it because on a production car fuel injection is better in every possible way.

Posted by: Rand Jun 12 2016, 10:29 PM

...

Posted by: OU812 Jun 13 2016, 07:09 AM

...

Posted by: Darren C Jun 13 2016, 07:42 AM

Sitting on the fence watching this thread unfold, it just seems to be another differing opinion of ego’s with little or no hard facts displayed in this thread (albeit the facts are numerous and available elsewhere on 914 world).
It’s unfortunately this type of thread that clogs up the ease at which I’ve been able to seek out useful and meaning information on this site. The net result is that I simply go and find out for myself rather than trying to wade through all the opinionated drivel.
My latest task was to see what happens when you fit carbs to a 2.0L FI stock engine. The only way I know how to get hard facts (rather than opinion) was to go do it, and get the car on a Dyno. I spent a whole day on the dyno, did 12 runs with various jet settings (increasing in steps of 5) and graphed Air Fuel ratio, torque and Horsepower through the rev ranges.
For clarity the 12 graph overlays have been thinned out to 3 runs showing a fuel band where best driveability v jet range was found.
Interpret this data as you will, it shows the pros and cons of fitting carbs over the whole rev ranges.
It’s not heated opinion its hard fact.

http://s265.photobucket.com/user/DarrenLCollins/media/914%20rolling%20road%20006_zpstvcyvisu.jpg.html

This information is worth far more than the 4 pages that proceed my post.

Posted by: GregAmy Jun 13 2016, 07:44 AM

The D-Jet in my '74 2L is not terrible, and is preferable in many ways. And in fact, the general design is damned close to what is being installed on new cars today. It simply suffers from being 40+-yr-old component technology.

Within the context of 1974 (1974, dude), I'd suggest it was a very forward-thinking, modern design.

Given the motivation (and cash), I'd toss a bigger throttle body on the car with a better TPS, a better MAP sensor, a modern tunable ECU (Megasquirt), and get rid of the four-decades-old wiring. Hell, I'd even toss a catalytic converter on the thing and see if I could tune it not only for driveability and power, but for emissions as well.

Carbs are a whole different kettle of fish (I'm re-learning them on my race car project) but you just can't beat the turn-the-key-and-go of electronic fuel injection. Learn it, love it, live it...I suggest EFI will eventually catch on in the modern marketplace...

Posted by: OU812 Jun 13 2016, 08:12 AM

I thank you for the comments and data

Posted by: John Jentz Jun 13 2016, 08:55 AM

Wow, 4 pages and no one states the obvious! PORSCHE had nothing to do with the engine or the fuel injection. It's a VOLKSWAGEN Typ 4 from stem to stern, top to bottom straight from the VW parts bin to the Karmann factory. It never spent a second at Porsche. In fact, the car with the exception of the -6's never saw the Porsche factory. If you look carefully at the ID plate it says VW Typ 47. Rant over.

Posted by: Jeff Bowlsby Jun 13 2016, 09:07 AM

Bravo, that is awesome info. Fuel delivery can only do so much to develop power, irregardless of the delivery method.

Posted by: Darren C Jun 13 2016, 09:20 AM

Thanks Jeff.

Now I throw out the challenge to someone running a stock 2.0L with FI (NOT MODIFIED) in any way and running well, to go do a dyno run and post a print out of HP v AFR and we can all see the differences between Carb & FI in black & white once and for all.

Posted by: Jeff Bowlsby Jun 13 2016, 09:27 AM

Here is a summary of the factory specs:




Attached image(s)

Posted by: dlkawashima Jun 13 2016, 09:28 AM

Quote from Hans Mezger, who oversaw engine development for Porsche back in the day ...

Posted by: John Jentz Jun 13 2016, 09:30 AM

Hi Darren,

Thanks for the info. Regarding the original question, the answer is EMISSIONs. What would your setup have provided in the way of HC's and NOx? US requirements starting in 1968 screwed up everything we held dear in performance cars. I know we can get away with non emissions HP mods with our 40 year old cars today, but it was far different back in the day.

Posted by: Darren C Jun 13 2016, 09:31 AM

Very Nice info Jeff, but it doesn't show AFR which is what we need to compare eggs with eggs.
Maybe i can convince a fellow UK 914 FI owner to visit the same dyno and then we'll get a fair comparison. However at $150 an hour for dyno time it may prove a big ask.
The data I just shared on here cost me 4 hours to obtain!

We all know the real answer was emissions, my input to this thread was to make it a little more constructive. As regards HC's and NOx, in UK we have an emission tests each year. Older cars are exempt but I still get mine tested for kicks. The 914 on a carb conversion likes to run rich (hence less mpg when you convert) at 3%CO it runs but pops and farts. 4% CO and its fine, but would barely pass the modern UK emissions test.
If you look at my graph the ideal AFR is 14.7:1, with carbs you will see they run between 13:1 and 9.5:1 in the jet range. Lower than a 115 main jet in a 2.0L carb car will get you close to 14.7:1 but you loose power & driveability (I tried it)
Bosch state that most spark ignition engines develop their maximum power at air/fuel ratios of 12.5:1 - 14:1, maximum fuel economy at 16.2:1 - 17.6:1, and good load transitions from about 11:1 - 12.5:1. However, in practical applications, engine air/fuel ratios at maximum power are often richer than the quoted 12.5:1,

This is the reason modern FI triumphs over carbs, because it can finitely vary the fueling to meet emissions.

Posted by: brant Jun 13 2016, 10:13 AM

ideal AFR for a 914 isn't 14.7
I think your own research shows that
and a DJet tuned for a more rich mixture does help
I've always done this to all of my F.I. cars

14.7 may be a goal in a laboratory... looking for emissions and theoretical burn
but with an air cooled motor, other traits come into play such as intake charge cooling, max power, etc...

in short, these cars like a more rich mixture under load (any time your not cruising at light throttle or idle)

its long been my belief that the historic valve seat problem with stock 914/4 motors was due to the factory setting up the fuel injection too lean in an effort to improve emissions/fuel economy.

empirically.. it is my observation that a lot less carb'd cars dropped valve seats due to running a more rich mixture and the cooling effects of a rich mixture on the heads

brant

Posted by: ConeDodger Jun 13 2016, 10:29 AM

Except that would be a pretty much worthless comparison. Unless the two were compared on the same Dyno with the same base settings and ambient conditions you still aren't comparing, how did you put it? Eggs to eggs?

I'm certainly not saying you can't make more HP (which is a worthless number because you don't use HP when you drive, you use torque) with carbs. I also said the reason for the change was emissions in a previous post. Carbs are so much cheaper to use than EFI that the bean counters would never have allowed them unless they were necessary for some other reason. That reason was emissions. But coincidently, EFI is far superior as far as flexibility, resolution, dependability...

We agree, but the scientist in me can't allow a worthless experimental model.

Keith Franke, a retired Lawrence-Berkeley Laboratory scientist and Lotus enthusiast once told me that carbs make up for a multitude of sins by being run "butt-ugly-ass rich." He redesigned the jetting on the dcoe Webers because he wasn't allowed to put EFI on the Lotus race car he enherited from his father. His Hypojets made the dcoe an almost civilized set of carbs. I ran a set of three of them on my 240Z for years. But, they can't compare to the control even rudimentary programmable EFI like SDS can give. You mention Stochiometric A:F and that is the magic emissions number but slightly richer is where the power and torque is made. The problem with carbs is that one step down from too lean on the jets is often way too rich.

Posted by: DBCooper Jun 13 2016, 10:58 AM

Sorry to disagree, but I don't think this information lends anything to the discussion. You were jetting carbs for power. So were any of your dyno runs done at part throttle? Then the results are applicable for full throttle situations, and how often do you drive your car at full throttle, what percentage of the time? So how is that related to "drivability"? And except at full throttle how does it shed any light in any way on "the pros and cons of fitting carbs", or any comparison of fuel injection vs. carburetors?

The reason no manufacturer uses carburetors any more is that carburetors are primitive and only fuel injection will give them the control they need to meet emissions standards. Fuel injection will meter the correct fuel/air mixture for ANY driving situation. Carburetors can't do that, simply can't, and that control isn't only emissions, it gives the same control over every aspect that affects "drivability". That was as true back then when Porsche/VW installed injection on these engines as it is now. Fuel injection is better today than it was then, but it's always been better than carbs. That's not a baseless "claim" because empirical evidence is easy enough to find, just do a google search of "performance comparison fuel injection vs. carbs" or anything similar and look for actual test results. For peak power, as in the dyno charts above, once jetted there's little difference between carbs and F.I., but for every other measurement that affects "drivability" fuel injection is better.

Excuse me for being undiplomatic but this isn't secret information, and to imply that Porsche "effed up" by choosing fuel injection is simply ridiculous.

Posted by: stugray Jun 13 2016, 11:12 AM

You mean it would have been (more useful) if you had presented any FI data to compare it to.

Posted by: gereed75 Jun 13 2016, 11:13 AM

Thanks Darren for the post. Wish it had been started in a separate thread for open discussion about carb tuning.

I have a wide band O2 sensor and gauge on my 6. After much research and consultation with very experienced folks to get jetting right, I see very solid 12.3 - 13.5 AFR's under pretty much the entire RPM range under driving loads (heavy throttle and acceleration and pulling hills etc).

However under partial throttle steady state cruising, I see AFR's in the 10's - way too rich for economy.

There may be ways to correct this, but they will require some carb mods not easily done (changing of idle air correction jets, that in the IDA 3C are not changable).

My point is, the triple throat Weber is a pretty sophisticated carb (PMO's are a bit better). Mine are tuned relatively well. They are fun and make good power when being romped on - otherwise they pretty much stink. They just don't carburate cleanly everywhere and probably never will..... short of doctorate level fiddling.

Am currently putting together an EFI system based on MFI throttle bodies. Really looking forward to seeing how well this engine can run!!

Posted by: brant Jun 13 2016, 11:28 AM

changing your emulsion tubes and float level would likely get you in the direction you want to go.... Also, the air correction jets have a profound effect on part throttle
Smaller primary venturi's also have a huge impact on part throttle and lower rpm/velocity mixtures...

more parts, more money, and more tuning could solve your part throttle NON PROBLEM.. that is easy to live with

Posted by: gereed75 Jun 13 2016, 11:44 AM

Thanks Brant, First let me say that I also consider it a non-problem. Partly just illustrating the point about how deficient even well tuned carbs can be...but I would also like to get it better.

The engine is a 2.4 with some head work done, DC 30 cams and 9.5 CR, single plug.

I have played a bit with emulsion tubes and am running F26's with 32mm venturi's.

Idle AFR's are around 12 (hard to tell, they vary alot).

From everything I have read and all I have talked to, the idle airs seem to be a definite factor. But, as you know they are pressed into the IDA 3C body.

Please tell me more about float levels. Mine are set "stock". I guess lowering them might effect the idle circuit towards lean???

Thanks man, now this thread is getting constuctive!

PS.... love your car

Posted by: SirAndy Jun 13 2016, 11:57 AM

So basically, you lost some 5 HP by switching to carbs.

A stock euro D-Jet 2.0L FI engine is rated at 100HP @5000 rpm ...

Posted by: rdauenhauer Jun 13 2016, 12:19 PM

Posted by: Jake Raby Jun 13 2016, 01:17 PM

Either system works fine, IF the user can tune it. The stock system is very analog, can't really be altered, or tuned, and the parts are hard to find. That said, my '76 is bone stock with EFI.

For a period of 3 years I went exclusively to PEFI for all my engines. The problem that I found was people thought that EFI didn't need anything, even though I told them the system would need baseline tuning for different elevations and weather conditions. I even had to fly to Lake Tahoe to support one engine that had been to 3 different shops after an install. Guess why the engine ran like crap? The installer (Porsche shop) installed the TPS backwards, so the engine would only idle. It pulled fuel as the engine increased RPM. I diagnosed it in 10 minutes, and fixed it in 5, but wasted two days traveling.

What we fight are complexities with installs, and the more wires, lines and etc an engine has, the better the chance that a human is going to screw something up that was perfect when it left here.

Thats why my engines come with carbs, at most someone sets the fuel pressure too high, or low. There's not much to screw up, and thats what matters most to me. Once someone gets to an advanced level they can add EFI themselves, and by that time I have been forgotten about, and my engine has proven it's self. That means they don't call me, which is the best case scenario.

Posted by: worn Jun 13 2016, 02:44 PM

I think this answers your own question. Very few people want to run WOT near redline most of the time. Passing another car, maybe. You don't use full throttle most of the time. Drivability is really important, especially when a buyer is out for a test drive. Even with a Porsche.

Posted by: Darren C Jun 13 2016, 02:57 PM

Hold on guy’s, I know the OP has got everyone hot under the collar….

Brant. I never said 14.7:1 is ideal specifically for a 914. It’s the best ratio for max power from burning gas. I agree totally with you, our cars run much richer.

Conedodger. I agree entirely with you, like I said in my earlier post the best comparison test would be an other UK members FI car on the same Dyno. The lower data in the graph show barometric pressure, relative humidity and temperature at the time of the testing if you want to get real picky with comparisons.

DBCooper, check the lower scale on the graph, its RPM, so you see the full AFR & HP across all throttle settings. Each of these dyno runs took 20 minutes over the full rev range against the force of the rollers, the Dyno’s computer takes the data and produces the graph. The rollers offer a resistance to the car so that you get a true representation of driving underload through the whole rev range. It's the only sure fire way to get meaningful data and a feel for driveability while plugged into the machine.

I’m not agreeing or disagreeing with the OP, just posting some data so that everyone can make up their own minds. Jeez even with hard data you guy’s still want to pick a fight as you only see what you wanna see.

Stugray, I agree with you, that’s why I said we need to compare eggs with eggs and welcomed an FI data post by someone else. Although I do disagree with you when you say its not as useful as the first 4 pages :-)
So as a fair comparison with all I can offer, lets look back at Jeffs equally informative graph of factory specs. His graph has Torque v Horsepower for the FI 914.
As I indicated earlier I have around 50 various data graphs from the 4 hours on the Dyno. Here’s the equivalent graph to Jeffs, showing HP & Torque but on a carb 914 through 3 jet sizes.

For info The dyno is at sea level in Portsmouth UK, the car is timed at 27 BTDC as per standard with stock cam, NO modifications other than just bolting on carbs.

http://s265.photobucket.com/user/DarrenLCollins/media/914%20rolling%20road%202%20001_zpsdzs7vaz4.jpg.html

Hopefully this’ll be a starting valued comparison for you Stu. Jeff or someone more computer literate than me can maybe post the two graphs side by side (Jeffs and the one above)

Gereed, Thanks for your post, I agree, the only way to truly optimise AFR is to go FI. You can pull the lean/rich issue slightly changing air correctors, but imagine the AFR graph line is a see-saw (pivoting in the middle, say around the 3500rpm point in the lower scale) if in your case your running too rich at part load changing to a smaller air corrector will tip the graph up a little at low revs but down at high revs. The pay off in trying to fix your issue with air correctors alone will be richer running at higher revs. This is where a lot of messing about and testing on the Dyno is needed, but as we all agree, FI makes this easier to control. Carbs are great but crude in this respect. However carbs can be fiddled with by any home mechanic, not many have the tools or knowledge to re-map FI. It’s horses for courses. As Brant says by changing more than the air correctors you could eventually get close to a perfect set up, but it will always run richer than an FI equivalent.

Sir Andy,
My car is a US California car, so its stock wasn’t 100HP. US spec GA 2.0 engine: 91 HP @ 4900 rpm is the figure measured by the U.S. standard SAE
In Europe the HP figure is measured by DIN which is 95 HP @ 4900 rpm for a U.S. spec GA 2.0 engine.
As I’m in Europe our Dyno measures HP in DIN, so I haven’t lost any HP at all, but thanks for asking!

So tin hat back on, I try and be helpful, offer facts not opinions, have no bias to FI or Carb and the guns point my way yet again?

Posted by: brant Jun 13 2016, 03:19 PM

thanks for the compliment

the float level will change which emulsion tube holes are exposed and have a big impact on part throttle mixture.

might be worth playing with (its free) and checking its effect with an AFR

but like you said....
not a big deal really... not an issue
that sounds like a fun motor!

we play with air corrections depending on certain corners at certain tracks.. that cause certain RPM/gearing outcomes
so If I have a flat spot as I transition to mains in a certain corner (lower rpm), that is causing me problems on the track, I can often move that transition point with air corrections to benefit one certain corner.... plus humidity and temp change through out the day
I often run different jets in the afternoon or different jets on sunday... than I did on Saturday morning. This is due to running too large of primary venturi's and essentially over carbureting a 2.0 motor. (loss of air speed/velocity for correct atomization at 4,000 -5,000 rpm)

but I only care about redline output so this is the way it is for a race car

right now I'm running 35mm venturi's on a 2 liter at 6,000 foot of elevation.
mains are usually around 175 or 180mains depending on the weather of the day
I carry everything up to around 215 mains for lower altitude tracks

I'm also running IDS carbs on this motor, and the 2ndary enrichment tubes really benefit mixture above 7,000rpm. You can literally see them kick in on the AFR gauge. They have to prime themselves, and are very noticeable on the mixture when they aren't working the first 3 times you run up to redline. The factory installed them for a reason on the S cars.... even though it was a one year change, right before they went to MFI (they even made the 2ndary enrichments in 3 different jetting sizes... but impossible to find)

brant

Posted by: SirAndy Jun 13 2016, 04:11 PM

Since you're in Europe, thanks for leaving out the (somewhat important) detail that your car has a US spec engine ...


PS: Do you still have the CA smog equipment installed? Are you using the stock exhaust and stock heat exchangers?
Because if not, the 95HP @ 4900rpm is not a correct baseline to measure against. To quote your own words "eggs with eggs".

Posted by: somd914 Jun 13 2016, 04:37 PM

From an engineering analysis perspective doing what you suggest above would be meaningless. What needs to be done is swap carbs to D-Jet on the same engine. Otherwise you cannot account for wear, build quality, etc. that differ between the engines and effect HP and AFR.

As for the above pages being useless, so is the original question. Just about any aspect of the 914, or any other consumer car, can be debated like this thread. One must keep in mind the goal is not ultimate performance, the goal is to sell cars and make a profit. And with that comes compromises in countless aspects of a car's design; these compromises include such considerations of reliability, cost, emissions, fuel mileage, safety, comfort, etc.

Posted by: Darren C Jun 13 2016, 04:39 PM

Sir Andy,
I'm not looking for a fight here.
As I said earlier my car is stock apart from the carbs, including stock exhaust and heat exchangers. The smog equipment came off the car as part of the FI removal.
That's all.
As for neglecting to to say it is a US spec car, it was you who assumed it was european, then chastise me?
My build thread and introductions on this forum show quite clearly it's a US car, photos of it in Desert Hot Springs CA and its importation to UK are well documented and it's listed on the register on here.
Why do I have to keep on making justification for every post I make on this forum?
It just creates fear to post by those who are less thick skinned than me.
Somd914, I agree with you, that would be the best comparison ever.
My reason for posting in this thread was to try and add some fact on why emissions drove the carb to FI move in our 914 and to in some way satisfy the OP without all the tit for tat that ensued over the first 4 pages.
Like anyone breaking up a fight, seems both sides have turned on me now and any good intent and good information is lost in the fractious. Hey ho.

Posted by: jd74914 Jun 13 2016, 05:11 PM

FWIW: Using the factory measurements from 30 years ago (taken on who knows what equipment and averaged over a number of engines) and comparing to new measurements is really irrelevant. Heck, dynoing your car on one dyno then driving down the street to use another isn't even a good comparison. The only relevant comparison is against a single dyno because no two share the same calibration, etc. The only thing you are really guaranteed is repeat-ability, assuming you are using a quality device. When dynoing a car you really should be looking at the shape of the curve and relative comparisons between changes, not the peak HP/torque number

To me it's quite impressive [and lucky] that Darren's plots are anywhere close in magnitude to the factory numbers. Note that the Dyno Dynamics one that Darren is showing plots from is an extremely well-regarded eddy current device which is very repeatable. It can also hold engine speeds/loads constant to produce really nice curves unlike inertial dynos which are much more common (at least in the USA).

It shouldn't be surprising that you can get better peak numbers on a carbed car than D- or L-jet car when just thinking about fuel mixing. Assuming both allow the exact same amount of fuel at a given time, fuel atomization from the carb will be much better. The Bosch fuel injector nozzle design is archaic compared to modern injectors.

Posted by: Darren C Jun 13 2016, 05:21 PM

Thanks Jim,

That's probably why it's $150 an hour for roller time!
I agree it was extremely lucky considering my car has 119,000 miles (1 owner with full history which shows no engine rebuild in it's life) Also it hadn't run for about 6-7 years before I bought it. All I did was pull the engine to change a couple of leaking oil seals and fit the carbs. All in all I am extremely pleased with this result. I bought it blind late one night off ebay, for a low price based on 6 thumbnail pictures and two bottles of wine.

http://s265.photobucket.com/user/DarrenLCollins/media/914%20rolling%20road%20002_zpsety8mb9j.jpg.html

http://s265.photobucket.com/user/DarrenLCollins/media/914%20rolling%20road%20003_zps1mltff55.jpg.html

Posted by: theleschyouknow Jun 13 2016, 05:32 PM

before I say anything (and I guess I probably shouldn't if I have preface it with a qualifier) thank you for posting your dyno results whether or not there is a FI comparison it is good info.
I am not a admin advanced or guru-member just a regular guy who has only had my car for a couple of years and I'm not itching for a fight or trying to belittle you or anyone in any way but...

really? you fear posting on this board? really? what are you afraid of? how many of these guys have you met (me only a handful and they were all super cool to me and I know I've posted my share of moronic questions/comments) do you think they will come to your house and beat you up or kick you off the board or ?

again please no one take offense but often all of us need to take a step back, if you or me or anyone posts something they think is earth-shattering info or even mildly interesting or relevant to whatever discussion and it receives less than your desired response -who cares?!?

if someone responds with something that ruffles your feathers (it is very difficult to either write or read tone) read around it (for instance you could skip the first 3 sentences of this post) for the info contained within very few posts on here are just flame jobs with no info contained within

I'm glad you're on the board Darren hell I'm glad everyone here is here because we all love these cars and the collective can keep them on the road much longer than any individual alone, especially me!


cjl

Posted by: MarkV Jun 13 2016, 05:34 PM

The fastest way to start an argument on a 914 board is to post anything that has to with carbs vs injection.

My previous car was a 74 L-jet car and it ran great but was always unreliable and left me stranded a couple of times. I was always able to diagnose it and get it working again with out a problem but I would rather drive my car than work on it.

My current car came with a set of Dellorto 40s. They were never set up correctly by the previous owner and didn't work very well. The first thing I did was track down a D-jet system with the intention of converting it back. Before I converted it I took some advice from here and changed the vents from 28mm to 34mm,installed smaller idle jets, bigger main jets & smaller air correctors. Didn't take much of a learning curve to get the car running really well. I also spent some time sorting out the anemic Bosch ignition. The car runs great and more important than that to me it is dead reliable. I haven't messed with the settings on the carbs in years. It starts all of the time and it runs at a pretty consistent 275 degrees. I would love to have injection but If it isn't broken why fix it. If there was some kind of turn key modern injection system that I didn't have to build myself I might consider converting it.

Posted by: Darren C Jun 13 2016, 05:37 PM

Thanks cjl, I'm not fearful, I just said some others with thinner skin may be put off.
Hell, I got a 2 week suspension last month for posting what I thought. No fear here!

Posted by: SirAndy Jun 13 2016, 05:50 PM

Yes, you live in Europe. Silly me for assuming someone living in Europe would have a European car. What was i thinking?

Posted by: rhodyguy Jun 13 2016, 05:54 PM

Posted by: 914_teener Jun 13 2016, 06:02 PM

That wasn't the context of the OP. "Did Porsche eff up?" The decision to go that way was made back the the 1960's. So yea...compared to modern injectors...they don't compare. But that was then. Now is now. The OP want to know "what is the best way to go". I'd assume that means now.

Even Jake who I consider has given a wealth of info and has contributed a lot here says either will work fine. Given you have the ability to tune it yourself. So...go for what you know. If not, then get out your wallet to pay someone else...carbs or EFI probably won't matter at that point.

I've had both carbed and EFI cars of several varieties. I kept the D-Jet on my car because that's what it came with. I know how to tune it. It is a highly reliable system and my car fuel mixture is right on the money. From a component standpoint it can be complicated as Jake mentioned. If I was in business...I wouldn't recommend it....too many call backs.

Some great discussion about carbs here but I'm wondering if the OP has decided which "way" he will go?

IMHO for street with a 2056 done right w-Djet....means cam...tuning...ect..can't
be beat from a smile/cost perspective and seat of the pants perspective. Most bang for the buck.

Carry on.

Posted by: 914_teener Jun 13 2016, 06:03 PM

Andy,

That'll be decided on the 23rd

Posted by: GregAmy Jun 13 2016, 06:11 PM

But I see they kick in the use of a big ass fan for the radiator airflow...

Posted by: Darren C Jun 13 2016, 06:14 PM

Look guy's,

I've got outta my seat and spent hard cash to obtain some (what I consider anyway) good information then willingly shared it free for the world to see on here.
I am asking nothing in return.

I'm not taking sides on the Carb v FI debate.

The data simply shows how jet sizing in a 914 with retro fitted carbs effects:

Air Fuel Ratio (and consequent mpg)
Driveability through rev range shown as torque
and Horsepower.

Whilst showing that factory HP & Torque specs can be met, by having to compromise on mpg.

I searched previously for some hard data, and basically came up with just strong opinions, so sought to obtain impartial facts that can be used to illustrate what's going on when you swap jet sizes, and the quirks in the graphs that you might not necessarily have predicted in response.

That's all folks......

Posted by: somd914 Jun 13 2016, 06:20 PM

Darren C,

I was just attempting to point out that even if you ran a stock, well running D-Jet 2.0 on the dyno, comparing your dyno numbers to this stock engine would not prove one way or another as there are too many variables changing in the engine that can't be easily quantified, and thus the discussion would not be resolved. It was not meant to be personal.

As for FI and emissions, agree emissions played a role but here in the US carbs were used up until around 1990. But I was attempting to point out that many factors (both internal and external) come into play (such as emissions) in the design of any product, and that has to be considered.

Posted by: injunmort Jun 13 2016, 06:23 PM

this is the stupidest thread i have ever seen. from op question to the responses. i have been flamed for many of my query. this is a tough group, but at the end and beginning, is the central question posed by somebody that does not have basic understanding of fuel delivery whether fi or carbs, let alone how those systems work. i think rabys response covers the controversy pretty eloquently.

Posted by: ConeDodger Jun 13 2016, 06:30 PM

Huh, and yet "this is the stupidest thread (you've) ever seen...

Posted by: OU812 Jun 13 2016, 06:45 PM

Thanks to everyone for contributing to this thread.

I do apologize if I ruffled some feathers, but really appreciate all of the technical data and opinions that were given on both sides.

Honestly did not know the Carb versus EFI question was Taboo. (I saw nothing in the rules about not being able to discuss it!)

If I would have simply posed the question, Carbs or EFI?....... how many responses do you suppose the post would have gotten? probably not all that many, and the responses would probably have been more of the yes/no/very little and general informational replies.

On the other hand by asking the same question only in a more provocative manner, it likely elicited many more in depth responses with a great deal of expanded information, actually more information than I ever thought.

As for my personal choice, for now I'm going to go with the stock EFI. Probably use the carb set up on one of my other 1.7 or 1.8 liters in a V rod setup, but that's another subject.

Hope I didn't upset to many of you, I can say one things for sure you are all quite knowledgeable and very passionate about your Cars, what's in them and I am glad to be able to take part in it.

In the future I will do better regarding the question and how it is posed.

Thanks again

Posted by: injunmort Jun 13 2016, 06:54 PM

hey corndogger, blow me , yeah it is

Posted by: Steve Jun 13 2016, 07:11 PM

Now that we beat this dead horse , its time to move on to 4 versus 6!!

Posted by: injunmort Jun 13 2016, 07:14 PM

your right, is it a hate crime or terrrtism? what if its both?

Posted by: Steve Jun 13 2016, 07:28 PM

IBTL

Posted by: OU812 Jun 13 2016, 07:38 PM

Your welcome to your own opinion, but The fact there were so many replies with really great data proves anything but it being The stupidest thread you've ever seen.

Just because people disagree doesn't mean their point of view is stupid

Posted by: injunmort Jun 13 2016, 07:42 PM

you are the op , obviously you are a retard, corndoggfhohole, a retard, where we going with this ?

Posted by: rhodyguy Jun 13 2016, 07:44 PM

Posted by: OU812 Jun 13 2016, 07:52 PM

I would say your crossing the line bud.

I have a niece that has Down's syndrome. People have used that word to describe her.
That is a vile description of someone that has a learning disability.

Using that type of language is not acceptable.

I think you need to apologize

Posted by: Mueller Jun 13 2016, 07:54 PM

No relevant data was posted, (the dynamometer graph has nothing to do with the factory using EFI)

Jakes comment has nothing to do with the factory using EFI. Even my comments do not answer it completely, it is pure speculation until we see something in writing or a video from someone at Porsche (or perhaps Bosch) saying why the switch to EFI.

Posted by: injunmort Jun 13 2016, 07:55 PM

what data? one guy from england posted a dyne sheet from england with carbs
. vague on the build, this is your proof?

Posted by: OU812 Jun 13 2016, 07:56 PM

I got a lot out of it,

Thanks

Posted by: gereed75 Jun 13 2016, 08:08 PM

Thanks Brant. I think I will lower my float levels a bit and then keep on keeping on.

This board can be a bit harsh at times, but Injin seems out of srts...should crawl back under his rock or back into his bottle

Thanks all and thanks again Darren

Posted by: Steve Pratel Jun 13 2016, 11:02 PM

Attached image(s)

Posted by: Steve Pratel Jun 13 2016, 11:10 PM

Those graphs were great, thanks.

Not sure they answered the mail on 'why' or driveability, but that was good data and makes total sense as I am trying to dial in my Dellortos. I'm using that data to go a bit smaller on my main jets and larger on my accel pump jets. LOVE this forum.

Not related to your graphs, I find the comments about this board being 'harsh' a bit amusing. I've been on BB's since the early 90's with SAAB NET and the XS11 Forum and from Jeep to SAAB, to G Body to COG, FJR, Subaru and a couple others, 914 world is total chill, and has been the best community so far and virtually troll and moron free. A bunch of cool guys, helpful and absolutely generous and gracious. IMO, the person who encounters troubles here brought them............

Posted by: veekry9 Jun 14 2016, 01:48 AM

https://www.youtube.com/watch?v=60Lb3-kYvc8

https://www.youtube.com/watch?v=vK8OX8xbka0


/
https://www.google.ca/?ion=1&espv=2#q=kugelfischer%20fuel%20injection%20pump%20for%20sale
Since 1968,efi has been the way.
Retro-fitting carbs to an injected T4 can be made to work tho.
Mapping egt back to back on a dyno is one way to make a valid comparison,quickly.
Another is time consuming trial and error testing,one change at a time,a seat of the pants,'feel' method.
The factory abandoned the mechanical carbs over injection 5 decades ago,so,
the question the op should have asked is 'Which efi system is most suitable for my application?'
http://www.total911.com/technology-explained-direct-fuel-injection/
/
Gee,I wonder who will be the first to offer a DFI system for the TFour.
Get sum soon.
https://www.google.ca/search?q=direct+fuel+injection+spray+pattern&espv=2&biw=1280&bih=642&source=lnms&tbm=isch&sa=X&ved=0ahUKEwi7ttm2jqfNAhVhxoMKHXOaAJAQ_AUIBigB#imgrc=rWgwvt4uUakTUM%3A
http://www.hotrod.com/how-to/engine/1501-direct-injection-is-the-future-of-efi/

Posted by: wndsnd Jun 14 2016, 08:10 AM

Too Funny Veekry

Posted by: Bleyseng Jun 14 2016, 08:15 AM

Here is my dyno chart from when my 914 2.0L was bone stock with newly fitted Djet.


Attached image(s)

Posted by: 914_teener Jun 14 2016, 11:56 AM

So......


Flatter torque curve with FI with aprox. a 5 hp gain with carbs.

For my street car I.ll take FI for a stock config.

Posted by: Darren C Jun 14 2016, 12:25 PM

Wow Geoff, thats great info. opening two tabs on my PC I can bring up my graph and yours and flit between to write this post. To make it easy for others I've edited it in here so you can just scroll up and down for comparison...

http://s265.photobucket.com/user/DarrenLCollins/media/914%20rolling%20road%202%20001_zpsdzs7vaz4.jpg.html

914_teener, the torque curve is about the same no flatter or curved between the D-Jet and the Weber 40 IDF's.
Take a look at the RPM scale at the foot of the graph, mine starts at a lower RPM, so by the time I'm at 2000rpm I'm making Torque about 118, peaking at about 122 whereas Geoff's D-jet torque peaks at 108 and his RPM trace starts at 2000 which is why it first appears flatter. (eggs & eggs scenario) if you could see Geoffs trace pre 2000 rpm it's gonna curve like mine. In fact you can just see it curve down, so if it were extrapolated I'd guess you'd be around 90-95 torque at 2000rpm Geoff....I'm making 118 torque at 2000 rpm on a 135 jet! (105 torque on a 125 jet and 108 torque on a 140 jet both at 2000 RPM both above the stock D-jet which is kinda curious too)

Brilliant data to show some "basic" comparisons Geoff. Thanks so much for sharing it's really made my day to see this real newly fitted D-jet data.....

Taking into consideration the US and Europe DIN & SAE scales I'm still up by 6% on peak torque WOW, I'm up by 15% on torque at lower RPM (2000rpm) and that's a real driveability bonus. Wow, Wow!

Don't suppose you have an AFR trace do you Geoff? I'd like to see what the trade off in mpg looks like between the two.

Thanks again Geoff, this thread just got a whole lot more interesting.

Posted by: stugray Jun 14 2016, 12:34 PM

Carbs vs EFI sounds surprisingly like this:


https://www.youtube.com/watch?v=FL7yD-0pqZg

Posted by: stugray Jun 14 2016, 12:53 PM

And here is a question that I pose whenever this comes up:

IF EFI is superior AND Porsche had EFI on the 911T & 911E (both MFI & EFI) then why did they opt for carbs on the 914-6?

The answer is: They intended to race the 914-6 from it's inception, and they knew that carbs provided more adjust-ability than the EFI did at the time.


Now if you want The tuneability of modern EFI with the "vintage" appeal of the stock EFI, then you can use 100% stock EFI parts from the D-Jet and add a Megasquirt for the ECU.

Two guys in my vintage racing group did exactly this.
They use 4X stock throttle bodies for ITBs and run E85 controlled via Megasquirt.

I am not positive, but I think they use aftermarket MAP sensors in place of the MPS.
Although I could make a circuit that would use the stock MPS and provide an analog output that the megasquirt can read and mimics a MAP but that just sounds like a lot of work.

Posted by: Jake Raby Jun 14 2016, 01:08 PM

The EFI system being more tunable is both a pro and a con for some people. The benefit comes from the ability to dial in fuel every couple hundred RPM, BUT the issue with this is that all of those increments require perfect tuning.

Again, this is why PEFI is not for everyone, but its also why some people love it.

I have cars with stock EFI, CIS, PEFI and carbs. They all have pros and cons, but at the end of the day I like whats simple.

Posted by: Darren C Jun 14 2016, 01:14 PM

Couldn't agree more Jake. I have cars with all manner of fuel delivery too, but the simplest always give me less trouble and when and if I get trouble, they're normally easy cheap fixes.

Posted by: Root_Werks Jun 14 2016, 01:24 PM

I like carbs and they have a place for the appropiate application. But, I've never really thought of them as more than a somewhat metered fuel leak.

Carbs only have a few inputs which AFM is adjusted. FI simply has more.

Posted by: stugray Jun 14 2016, 01:32 PM

One person's 'simple' is another person's 'complex'.

Which is more 'simple'?:

Plugin in a laptop to an OBDII port, download ROM from ECU, edit a table using a hex editor, reflash ROM to ECU?
OR
Pulling off an air filter, removing a mainjet holder with a screwdriver, swapping main jet, then repeating this 3 more times and replacing air filters?

Ask 5 people and you will probably get 3 different answers.

Posted by: Darren C Jun 14 2016, 01:41 PM

I totally agree with you Stu.

But at a guess I'd say that most folk on here would find it easier to lay their hands on a screwdriver at the side of the road than a laptop to an OBDII port, download ROM from ECU, edit a table using a hex editor, reflash ROM to ECU. :-)

Posted by: damesandhotrods Jun 14 2016, 01:49 PM

Using that kind of logic would lead one to believe that the 910, 907, 908, 917 and so on were never intended to be raced. Because those cars were all fuel injected. The 914/4 and 914/6 were too good, giving the 911 fits remember. The 914 got the 2.0 911T to keep it slower than the 911, so the FIA homologation required it to race with carbs. In SCCA, Porsche and SCCA made a deal to allow the 914/4 to race with carbs instead of the OG fuel injection…

Posted by: SirAndy Jun 14 2016, 02:00 PM

Why would you ever have to do the "on the side of the road" with a laptop? I've had plenty of idle screws come lose on my carb setups, but i never had to fix a broken FI by plugging in a laptop on the side of the road. That's not how FI works.

It's not like driving around somehow shakes the bytes around in your ECU mapping tables ...



I think you're really grasping for straws here ...

Posted by: veekry9 Jun 14 2016, 02:06 PM

BMW-X6M

What kind of carb yuh runnin?
https://www.google.ca/search?q=setting+carburetor+throttle+plate+with+feeler+gauge&espv=2&biw=1280&bih=642&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjiiuGToqjNAhXG6YMKHSlFDOQQ_AUIBigB#imgrc=4TDmZLsrOniHBM%3A
https://www.google.ca/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=synchronizing+weber+carbs
https://www.google.ca/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=weber%20carburetor%20air%20fuel%20mixture
https://www.google.ca/search?q=constant+velocity+carburetor&espv=2&biw=1280&bih=642&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj92rH_o6jNAhWFWh4KHSWHBgEQ_AUICCgB#tbm=isch&q=constant+velocity+carburetor+invention&imgrc=yEvyNyXRYfd_WM%3A
https://www.google.ca/search?q=constant+velocity+carburetor&espv=2&biw=1280&bih=642&source=lnms&tbm=isch&sa=X&ved=0ahUKEwj92rH_o6jNAhWFWh4KHSWHBgEQ_AUICCgB
https://www.google.ca/search?q=su+cv+carbs&espv=2&biw=1280&bih=642&source=lnms&sa=X&ved=0ahUKEwjS8aqPpajNAhUq7YMKHRWBCAAQ_AUIBygA&dpr=1.5
https://www.google.ca/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=lectron%20cv%20carbs
https://www.google.ca/search?q=mikuni+cv+carb&biw=1280&bih=642&espv=2&source=lnms&tbm=isch&sa=X&ved=0ahUKEwiGnsarsqjNAhUk54MKHUWDAQcQ_AUIBigB
https://www.google.ca/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=cv+carburetor+vs.+slide
https://www.google.ca/search?q=kendig+constant+velocity+carburetor&espv=2&biw=1280&bih=642&source=lnms&sa=X&ved=0ahUKEwi78Nrsp6jNAhXp34MKHQTcB4sQ_AUIBSgA&dpr=1.5
https://www.google.ca/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=predator+carburetor
Synchronizing carbs:
https://www.youtube.com/watch?v=GaTRyHxvneY
https://www.youtube.com/watch?v=Y_WDF6glD5k
https://www.youtube.com/watch?v=2PiQBr20kM8

https://www.sema.org/sema-enews/2011/19/creator-of-the-kendig-carbuertor-willard-kendig-passes-away

Posted by: Darren C Jun 14 2016, 02:10 PM

Sir Andy, et all,

Technology is fine, but everything has its limits. I’m not championing Carbs or FI here, but I’ll share a little experience I had last winter.
I was driving home from work alone on a back road and I suffered a TIA stroke while at the wheel, in seconds I was totally blind, and had no control of my left side. I was doing 50 mph at the time, and managed to bring the car to a stop using the grass verge and its feel through my right hand on the steering wheel. My first reaction was to feel for my phone to dial 911 (999 in UK).
But I had a smart phone.
Ever tried to dial 911 when you’re blinded by a stroke on a locked smart phone?
I thought I was gonna die there and then at the side of this empty road alone.
I opened the door and fell out the car into the road as I couldn’t stand up, blind and trying to shout for help with slurred speech.
Fortunately a passing car stopped and got me to the local Hospital ER (A & E in UK).
Smart phones are great, but I now have a Nokia 105 with buttons, so I can feel where the 9 & 1 are.
As has been said previously in this thread it’s what the individual feels comfortable with. The graphs I’ve posted along with Geoff are great to show what’s going on in a technical capacity, but everyone’s free to go with what they like.

Don’t lambast each other.

Don't try to be clever and nit pick each other.

If we all simply liked the same things the world would be a boring place.

Sure I get sh*t for my Nokia phone….but I’m not going to change it because it gives me a comfort that a smart phone can't ever do.


Hopefully you can get the meaning I'm trying to convey here...



Stu, your iphone 4 movie sure did make me smile.
Neither cartoon character need a damn up to date phone, it's just "stuff" that clogs our lives. All we need is a little understanding and each other.

Posted by: Tom_T Jun 14 2016, 02:18 PM

Well, with 7 pages of replies, you've certainly opened up a can of worms!

My perspective as a buyer in 1974-75:

IMHO - the Porsche 914 was the superior solution with state of the art EFI - & NOT dual/multiple Carbs to screw with - over the competing set of late 60's - early 70's sports cars & coupes in my budget which I looked at, including: MGB & C, Triumph Spitfire & TR4A & TR6, Austin Healy/MG Sprite/Midget, Fiat 124 Spider & Coupe, Alpha Spider & Coupe, Karmann Ghia, Porsche 912 (76 912E was the same 914 2.0L Djet), BMW 2002 (ti & tii were EFI), etc.

Even the fuel injected 911E of that period was considered the more tractable 911 model, and the 917 was MFI or EFI - NOT carbed, so go figure! Also the top powered 60's 427 Vette was the "Porcupine Head" fuel injected version. However, it was a time of transition to the newer FI, EFI & MFI technology, & most serious race teams made the switch to some for of FI.

I'd had enough of messing with & rebuilding carbs on my 1st 2 cars - a 68 Opel Kadett 2DR Notchback Coupe 1.1L & 69 Pontiac Ventura 4DR HT 400ci V8 - as well as with my folks', brother's, & uncle's & buddies' cars! And I certainly did NOT want to get into the royal PITA of synchronizing dual/multi carbs, constantly rejetting them for different altitudes, weather & other conditions, not to mention rebuilding more than one of the suckers per car!!

So I'm in agreement with the majority on here - emphatically NO - Porsche didn't eff up - then or now!!!!

My perspective as a new/used car buyer today:

New/Recent Cars - First off - try to name one car made today with carbs!? EFI is clearly superior fuel management for power, torque, mpg, emissions control, power/torque bands control over the range of RPMs, weather, altitude, etc. - so nobody does them on the new cars today, nor will they!

Classic Cars - No Carbs, unless that was they way they came as new & it's a restored or to be done as a classic build. For a Resto Mod - whether American Iron or Imports, most everyone is going with EFI Crate Engines, Mega-squirt, etc. EFIs for the reasons above & that others have said.

914 with Carbs:

So who is using carb conversions on 914 engines? Again there are some classic builds with carbed Porsche flat 6s, the Euro version of the 1.8L 914 (a cost saving measure for RoW by Porsche BTW, since they didn't need to meet Smog Tests for CA & the US), & as a cost saver on some 914 2.0L's built over 2056-ish, where the OE Djet doesn't work well.

Who else? Those who are too cheap to buy the proper OEM parts to fix their stock EFI, those who are either too lazy to mess with the more complex EFI &/or "...just don't know how to make these cars run properly" in the words of my Austrian born Porsche mechanic who was factory trained on the 914 in 1969-72 & has had his own shop since 72 (I've gone to him since he did the PPIs on 10-20 914s before I got my 73 2L back in 1975) - so a REAL GURU! .... not an online wannabe!!

Also note that our 914s are usually worth far more with either their original EFI (914-6 excluded cuz they were stock carbed), as well as on the better EFI "built" flat-4 resto-mods.

So, make your own choice!
Tom
///////

Posted by: OU812 Jun 14 2016, 03:40 PM

If indeed a 914 is NARP I guess it could be said Porsche didn't eff up?

Posted by: KELTY360 Jun 14 2016, 03:52 PM

Are you still implying that someone did eff up?

Wake up and smell the hydrocarbons.

Posted by: DBCooper Jun 14 2016, 03:54 PM

Now that's some of the dumbest bullshit I've seen in a while, and then, just when you think that one could never be topped it (good God!) just keeps on coming:

Posted by: OU812 Jun 14 2016, 04:06 PM

No, no one effed up.

I think EFI is the way to go, especially with a stock or near stock displacement engine.

Carbs would probably be more viable and useful on a "Big Four"
Type situation.

Posted by: OU812 Jun 14 2016, 04:09 PM

Are you drinking again?

Posted by: jd74914 Jun 14 2016, 04:53 PM

Since I've been sitting in front of my computer doing number crunching all day anyways, I thought I'd take a little time and use a little code to pull numbers from both the carb and FI plots and compare the two...

This plot compares the max power case from Darren (carb with 135 mains) with the FI case from Geoff. All that has been done here is pulling the curves off each plot and putting them all on the same chart. It might look a little different due to the axis dimensions. Note that I'm assuming Darren's power axis is reading in DIN HP so I corrected it to SAE HP.



At first glance, it looks like the carb'd car has both more power and a power band which is shifted lower in the rev range.

This next plot is the previous data normalized (ie: the data is divided by it's max value to force it to lie within a range of 0-1). Ignore the y-axis label, I just forgot to change it. Normalizing allows you to compare the trends. I did this because 1) no two dynos will read the same absolute values and 2) a correction factor for drive line losses is always applied, but the actual number is unknown since it's not recorded on these plots.

The curves look almost identical. Since they show the same trends and relative power differences, this leads me to believe that there is really little appreciable maximum power/engine speed difference between the two induction methods. Perhaps the carbs fall off faster but who knows... Just some things to think about.

Posted by: 914_teener Jun 14 2016, 05:29 PM

Those corrected curves display what Brad Anders has always said.

It.s nothing new and the data doesn.t show anything different then most of the "guru.s" already know.

The engineers knew what they were doing.

The business decisions and reasons are also there too.

They didn.t just use D.jet on tje account that it sounded like a good idea.

Posted by: 914_teener Jun 14 2016, 05:30 PM

...so given that why would you put carbs on a stock configured engine?

Posted by: OU812 Jun 14 2016, 06:00 PM

At this point, and after everyone's input on the subject, I wouldn't.......

Posted by: MarkV Jun 14 2016, 06:06 PM

1. Reliability

2. Simplicity

3. The ability to use a non Bosch distributor

4. The look

5. The sound

Posted by: OU812 Jun 14 2016, 07:09 PM

All in all, what's wrong with using one or the other because you "Like" them.

Many times folks choose something because they like it, not always because it makes sense........

Posted by: DBCooper Jun 14 2016, 07:23 PM

Nothing to do with drinking, I just have an aversion to loudly expressed ignorance and to trolls. So you said five of every six gurus preferred carbs to fuel injection and were asked several times who those "gurus" were. Gurus, right? No answer yet, so who exactly are they?

Posted by: veekry9 Jun 14 2016, 07:35 PM

Carburetor:Fuel metering device.
Fuel injection:Fuel metering device.
Same/same.

https://issuu.com/contact.magazine/docs/alternative_engines_volume_4_previe(turn to page 12)
How the internal combustion engine works,power is relative to the volume of air compressed.
Fuel burns at a ratio near 14.7/1 air/fuel mixture.
Charles Lindbergh flew fuel conservation flights to demonstrate that truth,no getting around it.(http://www.charleslindbergh.com/wwii/)
The new DFI allows very fine resolution of lean running conditions to alter that 'truth'.
Cruise condition cylinder switching allows a smaller fuel burn for greater range and emissions performance.
All good,the carb,much better than the Wright Brother's 'fuel plate',is a thing of the past in the 21st century.
So,go with what you know,for ease and price.

Posted by: SirAndy Jun 14 2016, 08:03 PM

1. My FI engine starts immediately with every turn of the key. No matter if it's freezing outside or boiling hot or if i'm at sea level or 10,000 feet up.
I've had this engine for 10 years now with only changing oil every once in a while and changed the spark-plugs once.

2. Have you ever dis-assembled a carb?

3. OK

4. Personal preference, i quite like the look of my engine.

5. I'll give you a ride in my car and we'll talk about the sound again afterwards.

Posted by: Bleyseng Jun 14 2016, 08:35 PM

Posted by: 914_teener Jun 14 2016, 08:37 PM

Fixed it.

Posted by: Jake Raby Jun 14 2016, 09:41 PM

Hell, I still have some cars with points, and condenser too... But I favor a mechanical diesel that only has one wire in the engine bay, and that kills the fuel control to shut it down.

Posted by: MarkV Jun 14 2016, 10:15 PM

1. I never mess with my Dells....I rebuilt them and jetted them when I got the car.... easy to work on.

2. I don't live in the cold. As cold as it gets here it still always starts.

3. Every Bosch distributor I have owned had a dwell & timing that bounced... they can't be dialed in without a distributor machine. The cap is too small and the electrodes are too close together. The Mallory is totally adjustable by the user....multiple advance curves and springs.

4. Maybe?

5. I like the sound. If I want to talk I drive my daily driver.

I have the injection in a plastic box in my garage I just choose to run the Dells.

Posted by: Mike Bellis Jun 14 2016, 11:08 PM

I did not read through all 9 pages...

EFI/FI was developed for fuel economy not maximum performance. The early 70's saw the oil embargo and every manufacturer was trying to make a smaller more efficient vehicle. Emission standards were also getting tougher to meet.

Technology has vastly improved since then. EFI is far more efficient than carbs. Even for max HP. Any rpm or load can be programmed in a modern aftermarket system. Porsche still does not tune for maximum HP, rather it's a balance of performance and driveability. They are leaving HP on the table because no one wants to drive a drag boat on the road; all on or all off.

Did they screw up? No. They integrated the newest technology of the 70's in search fo a balance.

Posted by: Darren C Jun 15 2016, 01:44 AM

Jd74914, Thanks for taking time out to overlay both graphs. Great work!

As you say, and I and others have said the only real comparison is to have two cars run the same dyno.

Once you start to manipulate/compute two separate sets of data from 2 separate dyno machines to “average” them you get an average but not accurate result. I’m going to try and convince a fellow UK D-jet car to run the same dyno as mine to get a better idea -still expecting someone to say afterwards; hey it was sunny one day and raining on the other ;-)

Your overlay graph is interesting as the tail off at high rev range may mean I need to look again at my Air Correctors, or it may mean that the two separate machines had slightly differing calibration on their ability to measure RPM? That’s an interesting thought as it would pull my early gain in torque in line with the D-jet, and push my late drop off in torque back to match the D-jet.
It’s all probably old news to the anonymous guru's, but I haven’t been able to find good graph data comparing a stock D-jet and a stock engine just running carbs with no other modification or parts changed; only strong historical opinions of the results in a “because I say so” format. Or data on hot cam modified engines where it is hard to make comparisons.

What has been shown in this thread from the data is that at the HP and torque on two standard engines, one with carbs one with D-jet are pretty much the same. So it follows that the drive would be a similar experience.
Now I’d love to see the AFR (Air fuel ratio) trace for the D-jet for a similar comparison to my first graph so that we have the data for emissions, and can see the fuel economy differences in cold hard facts. We all know the Carbs will be running richer with less mpg and higher emissions but the data will make an interesting read and would be more useful than a “because I said so or he said so” response. OP, we know the factory changed to FI based upon emissions, let's wait to see the AFR data from the D-jet to compare the two otherwise stock engines, and it'll hopefully show why they didn't eff up.

Jake, love your reply! I have cars with Magneto ignitions and Autovac fuel supply!

Posted by: OU812 Jun 15 2016, 02:14 AM

Oh DB,

I believe thou is the ignoramiss within this thread.

Has thou not seen and read all thee those Guru's have said?

Obvious is the troll, it is not I, for I have resigned myself to EFI.

So DB open thy mind, thy heart, thy soul, let all the data sink in, then thou will know.

Whether it be EFI or Carburation in your ride, it is ultimately up to thy owner to decide.

So rather than holding on to anger and such, let it go before thou appears to protest to much......

Posted by: Darren C Jun 15 2016, 02:47 AM

Jeez, did you stay up all night to write that poem? It's 9:43am here in UK, so I'm up and about. What time is it in Minnesota?
Me thinks the tit for tat may be consuming you.

Posted by: OU812 Jun 15 2016, 03:58 AM

No ....working on a emergency water main break overnight in Bloomington, Mn.

Looking forward to fixing this, then working a full 12 hour day shift afterwards.

As far as tit for tat ........I'm good!

Posted by: stugray Jun 15 2016, 07:22 AM

I would like to see two exactly stock engines on the dyno EXCEPT:

ONE engine has a mild carb cam, dual webers, and tangerine racing's street exhaust.

I am guessing an easy 15-20 hp over same engine with stock EFI.

And there is another reason to have carbs on an otherwise "stock" motor: Vintage racing.
I would have a megasquirt instead of carbs if the rules allowed it.

Posted by: Mueller Jun 15 2016, 07:44 AM

I never had a 914 with carbs (except for the /6 I had for a few weeks) I've tempted to buy carbs for the current car but will probably stick with the LJet since I don't want to dump too much money into it.

Posted by: sb914 Jun 15 2016, 07:59 AM

Posted by: Bleyseng Jun 15 2016, 08:04 AM

I still have to dyno my 2056 with a Raby cam and Djet as it should be in the 115-120 hp range. 25mpg and tons of torque....so who needs carbs as it looks totally stock.

Posted by: DBCooper Jun 15 2016, 09:30 AM

No, no “tit for tat”, just a simple request for substance that you've repeatedly ignored. You said “Many of the Guru's (about 5 to 1) prefer carburation.“ Now that’s a surprising fact that you then used to infer that Porsche “effed up” by putting fuel injection on their engines, questioning the competence of Porsche engineers. Those are statements you made, so I’m just curious to know where you get this information, who you consider a “guru,” and why you think they’re better than the Porsche engineers. Simple enough. You’ve been asked several times who these “gurus” are and you have time to rhyme, so what’s the problem?

By the way this isn’t a new question, google “carbs vs. fuel injection dyno comparison” or anything similar and find lots of empirical comparisons complete with charts and graphs. Generally carbs can equal fuel injection at wide-open throttle, so a draw there, but fuel injection is more efficient and performs better at all RPM points below wide-open. Meaning the Porsche (and every other car manufacturer's) engineers were right, no surprise. As to the “look” and the sounds of carbs, those are purely subjective so really silly to argue about.

Posted by: 914_teener Jun 15 2016, 10:33 AM

Glad to see you posting once and a while Geoff.

Posted by: OU812 Jun 15 2016, 10:50 AM

This thread has had more than five knowledgeable people weigh in on both sides of the issue.

I never considered this to be an argument, rather a spirited debate with the hopes of learning from those more educated than myself.

Posted by: Mark Henry Jun 15 2016, 10:58 AM

My new 3.0 performance /6 has weber's, got them cheap in a trade.
Although I like FI, that's what I will run unless I'm disappointed with them.
Still hoping to get my car back on the road this year.

Posted by: jd74914 Jun 15 2016, 11:41 AM

It's not unheard of for dyno engine speed measurement to be incorrect. There is a Dyno Dynamics brake locally which measures engine speed in error by ~200 rpm. We used to go and then scale all of the data back and recalculate torque at home.





If you compare the normalized curves, I'd guess one of the dynos was measuring off by ~225 rpm since the curves are nearly line-on-line with that shift. My guess is that the slope of the curve is different between yours and Geoff's because there is a slightly different driveline loss multiple (Cl) being applied. Given that, it does look like yours drops off sooner so there is probably some more carb tuning to be had.


For the record, I hate working with carbs...when you're on a dyno or tuning in general it's so much easier just to change a few numbers in a table! Well, at least until you work with something high end the likes of AER/Life Racing, etc. and they you have 20 tables to work with.

Posted by: Racer Jun 15 2016, 02:14 PM

No mess ups.. it was "cutting edge" technology back in the late 1960s when the car/engine was coming together.

I can't think of ANYONE else who built and offered in 1970:

Mid engine
Electronic Fuel injected motor (911s had either carbs or MFI)
5 Speed syncromesh trans (even base 911s came with a 4spd)
4 wheel disc brakes
4 wheel independent suspension
Nearly 14 cu ft of combined trunk space
Removable Targa top

All for $4K ?

Posted by: gereed75 Jun 15 2016, 02:26 PM

Wait, There were some really nice 20 year old designs from MG, Triumph, and Fiat to pick from!!

The X 1/9 was a modern design but with a sub 2 liter carbed POS engine and midget driver space.

The 914 was serious engineering when it appeared. Very cool!! It was kinda "mini exotica" for the common man when cars like the Lambo Muira and the Pantera were the shit. And you could subconsciously link it to the all powerful 917!!

I do admit to some mid engine lust for the Lotus JPS Europa, but it was just too quirky for a street car.

Posted by: ClayPerrine Jun 15 2016, 02:28 PM

Posted by: OU812 Jun 15 2016, 02:29 PM

I know .....what a value for a cutting edge platform!

Posted by: Darren C Jun 15 2016, 04:31 PM

Thanks jd74914, again great work on the data, and it makes complete sense with my gut feeling that the two Dyno traces had an inaccuracy somewhere in RPM.
I agree about a little more fine tuning on my particular car might be needed just to delay that drop off in curve at the end. That's why I'm hoping someone out there has a D-Jet stock AFR trace so I can see it's fueling. I'd guess I need to lean off my AFR post 4500RPM to get an exact matching D-jet curve (it isn't far off mind you already). But to be fair, I don't plan on sustained running at those RPM's. I have more of a classic car Sunday cruise plan for my 914, as I've got other big brutal monsters in my garage already that'll pass the 200mph mark and set my pants on fire, so don't need to prove anything with this 14. :-)

Posted by: brant Jun 15 2016, 04:57 PM

You don't want to match a stock djet afr trace!

The actual fuel used today is a much different blend than the blend that cars were set up for by the factory

Whether it's a difference in fuel blend or the factory's tune for emissions and economy. The stock are trace is not ideal.

I retune my stock fuel injection for a more rich mixture and still get 31-32mpg on the highway (1974 2.0)

Posted by: Bleyseng Jun 15 2016, 08:33 PM

I have another dyno chart somewhere and the AFR is pretty flat at 13.5 to one upto 5500rpms


Attached thumbnail(s)

Posted by: Darren C Jun 16 2016, 12:47 AM

Hi Brant, I think I didn't explain well or the meaning in my post is mis-understood. The D-Jet curve I'd like to match is the end of the HP curve, where it looks at the moment mines dropping off early. The AFR of the D-jet I'll never be able to match as the car would always want to run richer with carbs.
I'd like to see the AFR of a stock D-jet just for curiosity and to gain knowledge and understanding of the "benchmark" and also as a comparison to what happens to the AFR through the rev range when you fit carbs.
I agree totally that stock classic car engines (of all types) on modern fuels and with a good few miles under their belts often benefit from running a little richer than 40 years ago when they were new and running on older fuel types and blends.

Geoff,

If you have another graph with AFR trace that would be brilliant! Better to have your trace as it goes with the data you already posted so the best info we could have!
Thanks in advance

Posted by: euro911 Jun 16 2016, 01:37 AM

Hey fellas, what's the best oil for air-cooled motors?

Posted by: falcor75 Jun 16 2016, 01:54 AM

Oh no you didnt....

Posted by: brant Jun 16 2016, 05:40 AM

It depends on which tires you are running...

Posted by: veekry9 Jun 16 2016, 07:04 AM

And on the tenth page,they lost their minds.




/


(aircooledtechguy pix),T4 exhaust,section thru studs.

The beauty of the DFI is the lack of cylinder wall washing by raw fuel,improving ring life.
Drill and tap a hole into the chambers,preheat and tig weld the barrel from the chamber side.
Final drill and tap for the DFI injector,then,machine the head complete.
A dry flowing int port can be reshaped,without the unatomized fuel pooling out of suspension.
/

T4 intake,section thru valve guide and seat.


Good pix of the T4,T1 heads in sawn sections,as above.
http://www.thesamba.com/vw/forum/viewtopic.php?t=602256
Unlike the second plug proposal,a DFI install ought to enter the chamber from the intake,"fat"part of the chamber.
Could it be as good as 20HP/TQ across the graph?
/

Posted by: Chris H. Jun 16 2016, 07:54 AM

Brant can I run a 205 series tire under stock fenders? What size do you guys like? Hope this hasn't come up before.

Posted by: rhodyguy Jun 16 2016, 07:57 AM

Maybe Chris. Depends on your wheels and the chassis.

Posted by: DBCooper Jun 16 2016, 08:16 AM

Idiots!! [grumble, grumble] Use the gotdamm search function!!

Oh yeah, the horse! Gotta take out some of this hostility and abuse that poor long-suffering horse!!

Posted by: mbseto Jun 16 2016, 08:36 AM

Since we are digressing...
Always thought the six-stroke engine concept would be cool to apply to an air-cooled engine:
http://autoweek.com/article/car-news/inside-bruce-crowers-six-stroke-engine

An additional set of strokes is added to inject water into the piston. It turns to steam from the stored heat of the piston, so it gives an extra power stroke while cooling the cylinder at the same time.

Posted by: rhodyguy Jun 16 2016, 08:43 AM

Interesting article.

Posted by: veekry9 Jun 16 2016, 09:04 AM

The main crankshaft with one(of four) rod and piston. The power is taken off this crankshaft while the top crankshaft operates the small top pistons to give favourable port openings. (Cars and Drivers)

https://primotipo.com/tag/bob-chamberlain/
Well,this '40s engine type would now be a viable proposition with the DFI tech available today.
Swinging the twincrank to beyond 12K,with fuel efficiency never before possible.
A moment cancelling design,smooth.

/

Posted by: Darren C Jun 16 2016, 12:39 PM

Very interesting Veekry9,

While we're going off course a little...

I was an Engineer in the Navy for 18 years and one of our engine types was a Napier Deltic, I led teams rebuilding, replacing and maintaining them. They had opposing pistons and 3 cranks in a delta (triangle) layout.

https://en.wikipedia.org/wiki/Napier_Deltic

I also worked on an array of gas turbines, from full tear down and rebuilds to straight replacements, and general servicing. These included Early marinized Rolls-Royce aero engines, Tyne, Olympus (same engine as our Concord jet plane had) and Spey, I even qualified in the Harrier jump jet Pegasus too. We also used the Rover turbine (as a fire water pump) I rebuilt a few of these too. A very similar Rover BRM basic design copy engine was used in the Howmet race car.

https://www.youtube.com/watch?v=GAgLSy371us

I've actually help fix one of these gas turbine race cars in the paddock at Goodwood!

The complexity of the Fueling systems on these babies would blow your mind in comparison to D-jet :-)

Posted by: Steve Pratel Jun 16 2016, 01:20 PM

The REAL question is "Why did they design an engine that needed oil?" Did they Eff that up too?

Posted by: ClayPerrine Jun 16 2016, 01:24 PM

Posted by: wes Jun 16 2016, 02:38 PM

Ah Oil is thicker than water!

Posted by: veekry9 Jun 16 2016, 02:54 PM

Yeah,the Moon had not yet been traveled to,and turbine and Wankel engines were going to be the next big thing.
Today,I would surmise the vast improvement in materials would make a turbine/electric/magnetic/hybrid car
a marketable space age set of wheels.Heck,you could run it on recycled cooking oil/kerosene/mdo.
A set of igniters in each cylinder,to initiate a more complete burn will likely be the next big improvement for piston engines.
High temperature magnesium,whodathunkit?I'd like to see the response a lightweight reciprocating mass as applied to the
aircooled engines would have.The crank could be lightened substantially,piston velocities near or beyond what F1 is attaining today.
Something old is new again,the Napier is a diesel in the marine application I would guess.
Diesel with solid state spark ignition,when was the last time that was tried,I wonder?
Mg:
Cost, pure: $3.7 per 100g.
Cost, bulk: $0.29 per 100g.

http://www.hotrod.com/how-to/engine/hrdp-1009-what-ever-happened-to-smokeys-hot-vapor-engine/
https://www.google.ca/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=laser+ignition+piston+engines
https://www.google.ca/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#tbm=vid&q=rover+turbine+car+documentary
With the modern control of fuel by electronic means,EFI,the leanout of the chamber could be attained,a temp not possible then.

Appears you've had your sea legs for a lifetime.
Been to the Bay o' Biscay?(Cockney)
https://en.wikipedia.org/wiki/Rogue_wave

Posted by: 87m491 Jun 16 2016, 03:01 PM

Dupe post Never mind

Posted by: OU812 Jun 16 2016, 07:58 PM

How about a Ceramic Wankel? smooth, torque, more hp, better fuel economy better burn because of higher operating temps.......not sure about the effin oil though

Posted by: Darren C Jun 17 2016, 05:45 AM

Yes the Deltic is a Diesel in Marine form. It had two types of starter motor, the first was an air turbine, the second was a holder for shot gun cartridges, that you fired and the explosion cranked it over!

As for sea legs, yep you could say I've had had more than my fair share at sea and sailed the bay far too may times to count.
That rogue wave info is interesting, like the Clooney movie "The Perfect Storm", I've been at sea in these conditions twice. once in 87 and again in 96. In 96 I was Marine Engineer Officer of the watch on a Type 23 frigate (they were brand new back then) and we got into a terrible storm. The ship started to split in two. Cracks developed on 1 Deck abaft the beam forward of the hanger and aft of the superstructure. We had two teams around the clock with tape and marker pens, measuring how wide it opened and how fast it moved across and down through the ship, marking and timing each progression. It went completely across 1 Deck and then started going down through 5 Deck and then below. The Frigate was being tossed like a cork, we didnt sleep for 3 days, being thrown around inside, pumping out water while the crack only needed to go a few more feet before it got to water level and the ship would have flooded, broken in half and been lost.

Never underestimate the power of nature.

Fortunately we limped back to Portsmouth and I help the dockyard shipwrights repair the damage. From then on all Type 23 had an enormous gusset welded in between the hanger and superstructure on 1 deck to strengthen for this calculated 1 in 100 year event.

So back on track....Any news Geoff on your AFR D-jet trace?

Posted by: Bleyseng Jun 17 2016, 09:38 AM

Look back one page where I posted it.

Posted by: Darren C Jun 17 2016, 12:29 PM

Thanks Geoff, that's what happens when there's too much distraction in another direction....didn't see it!

But now. That is impressive, very stable and good burn. I doubt you'd get engine running smooth, driveable and with the same power & torque on Carbs at this AFR level you'd need 115 mains or below on a 2.0L to get anywhere close.

So OP, this is why the factory went D-jet. Right there in Black & White. ;-)


QED

Posted by: Brian Mifsud Jun 17 2016, 02:05 PM

If you really want to know the answers to your questions, you need to do some reading offline. Take it directly from the horse's mouth:

Get a copy of "Excellence Was Expected" by Karl Ludvigsen.

You will not only get an explanation of WHY Manifold Air Pressure Fuel Injection was chosen for the 914, but how Porsche went about making their decisions. You will also get the entire history of the company.


If you don't walk away after reading that book with a great deal of respect for the company, the decisions they made, and their place in history then it staggers the imagination why you'd suffer through the expense and hard work of owning and maintaining an old German car.

Part of owning a Porsche (even a NARP 914) is appreciation of the brand and the engineering. If none of those matter to you, sell the 914 and get a Honda.

Posted by: OU812 Jun 17 2016, 06:36 PM

Thanks for the reading recommendation, I found it and read some of the reviews on line...Looks like a great read.

I actually already have a great deal of respect for the Porsche name and engineering that went into the vehicles. It all started when my Dad started selling the majority of his Vette collection and started buying Porsche's. One of his I remember most was a 1964 356SC. He saw it in 1975 sitting in used car lot in Minneapolis(Westside Volkswagen) the dealer got it on a trade. it needed a ton of work, which was fine due to the fact Dad owned a body shop and Westside was one of his accounts, he also new the used car manager. After a lot of negotiating it was his for 600.00 bucks. this car provided many firsts for me. Learning how to use saddle soap and rubbing until my arms where sore. The heavy thick brown Leather softened up and looked like new.(Never forget that smell either) The interior chrome, it was amazing how much chrome there was in these small Marvels, using chrome polish until the fingers almost bled and going through a box of rags ending up with a pile of used black rags and black stained hands. Working through the rest of the Interior, the carpet and of course the Coco mats. It was a labor of love. At the time he had a Old school body man that removed all of the rust, he could fabricate any shape bend or curve with sheet metal, then I believe he would use "lead" to fill the dents or seams and file the panel until it was perfect. I cannot remember the exact color name, But it looked like Milk Chocolate, Brown chocolate. Bone stock beautiful. I can remember going out in it. Pop would get it singing down the country roads. He would often try to scare me a little be laying on the brakes and taking his hands of the wheel. The car never failed to stop quick and straight. I always liked the Porsche because if you owned one you "Didn't see yourself coming and going" Its unique shape and sound
always got looks. Since I purchased my first 914 this last February, I have yet to see
one on the road. I find myself wishing I could work on them daily. Like many I cannot wait to get them of the road.......

Posted by: OU812 Jun 18 2016, 09:23 AM

"Part of owning a Porsche (even a NARP 914) is appreciation of the brand and the engineering. If none of those matter to you, sell the 914 and get a Honda."

The above statement is true for some of us but not all.

Many have foresaken the type 4 and its factory fuel delivery system.
for a Chevy, Subaru, and yes even Honda engines and their respective
Fuel delivery systems.

So besides being Porsche, I think that is why the 914 appeals to many. It has so many ways to personalize it....

Posted by: OU812 Jun 24 2016, 10:18 AM

"Excellence was Expected" wasn't what I expected. While it was a good read it more was slanted toward the racing end of things... Didn't really include much to do with the civilian side (non race) of things. I would have liked to read more with regards to how and why they made their decisions relating to the consumer end user and not so much the Racing enthusiast.

It was Ok.

Is there any other good reads more related to the non race, more consumer side of the developments ?

Posted by: barefoot Jun 24 2016, 11:45 AM

With this being the case, Did Porsche mess up when they went the EFI route with the
"Excellence was Expected" wasn't what I expected. While it was a good read it more was slanted toward the racing end of things... Didn't really include much to do with the civilian side (non race) of things. I would have liked to read more with regards to how and why they made their decisions relating to the consumer end user and not so much the Racing enthusiast.

It was Ok.

Is there any other good reads more related to the non race, more consumer side of the developments ?
[/quote]
Try Wikepedia for a brief history.
Remember that the D jet system used on early 914's was already in use for 2 years on VW Square & Fastback cars.

Posted by: OU812 Jun 24 2016, 12:43 PM

[quote name='barefoot' date='Jun 24 2016, 12:45 PM' post='2363458']
With this being the case, Did Porsche mess up when they went the EFI route with the
"Excellence was Expected" wasn't what I expected. While it was a good read it more was slanted toward the racing end of things... Didn't really include much to do with the civilian side (non race) of things. I would have liked to read more with regards to how and why they made their decisions relating to the consumer end user and not so much the Racing enthusiast.

It was Ok.

Is there any other good reads more related to the non race, more consumer side of the developments ?
[/quote]
Try Wikepedia for a brief history.
Remember that the D jet system used on early 914's was already in use for 2 years on VW Square & Fastback cars.
[/quote]

Good point on the D jet.

Posted by: Rand Jun 24 2016, 01:16 PM

I see what you did there with the subject change. Having second thoughts about the "eff up" question?
Now you are asking if they expect excellence. Well, of course they always strive for it. Some things work better than others, but over time it's always about improving over the previous technology.
Are all your questions rhetorical?

Posted by: OU812 Jun 24 2016, 01:32 PM

Nope nothing rhetorical at all

Excellence was Excpected is the name of a recommended read.

No second thoughts, More what could have or should have been done by the engineers at Porsche to supply the end user with a "True" Porsche. That's all

Posted by: The Cabinetmaker Jun 24 2016, 01:45 PM

I think his new thread wasn't drawing any drama, so he resurrected one that should just die.

Posted by: KELTY360 Jun 24 2016, 02:02 PM

Now you want to play the "True Porsche" card??? I wish you'd learn to use search features so you wouldn't clutter up the board with 'loaded' comments and questions.

Posted by: Mueller Jun 24 2016, 02:33 PM

Couple of Q's for the thread starter:
Still watching black and white TV? If not, why not?
Still using a 386 based processor? Why not?

I doubt it, it is called progress. Of course black and white TV's and 386 based computers "work" so you shouldn't need anything newer.

http://www.cardiagnostics.be/-now/Educational_sites_bestanden/BOSCH%20L-Jetronic%20Injection%20Manual.pdf

See above link...They explain why in print, starting with page 3..
"can already comply today with the exhaust gas legislation of tomorrow"

If you read any of the manuals for D-jet or L-jet they specifically call out what the CO2 levels should be for each particular model, that number is there for a reason (emissions) Yes I know not all places care about smog or emission numbers, but they would rather not build a vehicle that is compliant in only certain areas (like the old goofy CA only smog rules, some models not legal for CA yet legal in all other states even those that are direct neighbors)

And if you think Porsche was all alone in the bad decision to go EFI, please feel free to criticize Saab, Volvo, BMW, Mercedes-Benz and Jaguar since they too started to use the same exact fuel injection as Porsche did with the 914.

I am glad to know that 914world is blessed with someone like you that is surely smarter than the thousands of engineers from those above companies.


http://www.lanuv.nrw.de/fileadmin/lanuv/luft/pdf/X735-Bruckmann_50-years_part-1.pdf

It appears Germany started to be more concerned with CO2 and smog in the '60s. Being that Bosch is a German company they had a huge finacial interest in getting these numbers down to an acceptable level.

Even the manufactures of carbs started to do R&D on EFI and had implemented it years ago.

Posted by: OU812 Jun 24 2016, 03:49 PM

I could say "now you get to decide what clutter and loaded Questions are?"

There have been numerous threads that have far less important subject matter in them than this one, and I don't find myself telling the OP they should not have started a thread because the subject has already been covered, or its clutter. Search functions don't always provide the info looked for. Finally if all got their answers from the search function and because of it didn't post....this would be a fairly slow and uninteresting site...

Posted by: euro911 Jun 24 2016, 04:04 PM

... but this one keeps going over the same old ground. D-jet & L-jet FI from the 70's ... it is what it is

Posted by: Mueller Jun 24 2016, 04:17 PM

OP is working on a time machine. He will convince Porsche they should have kept carbs

Posted by: 396 Jun 24 2016, 04:25 PM

I think the OP simply has too much time and would like to bump his tread up so he will be noticed as a value contributor.

Posted by: OU812 Jun 24 2016, 04:28 PM

What do you mean by "bump"

Posted by: The Cabinetmaker Jun 24 2016, 04:30 PM

Posted by: Mueller Jun 24 2016, 04:38 PM

as simple as it sounds...you bump something it moves....in the case it moves to the top of the list..

Posted by: OU812 Jun 24 2016, 04:49 PM

Alright simple question

914/4 EFI. 914/6 Carburated ...why?

Obviously many here would gladly trade
Their 4 for a 6 which didn't come in a fact
EFI configuration back then....if the 6 was
Truly all Porsche then why put a set of
Garbage (?) carbs on it? And go with what
Some are saying is the far superior EFI?

I just doesnt make sense.

Either Porsche was lazy and didn't want to go all the work to inject the 6, or they thought it to be in exact and not worthy of installing on the 6.

I don't know...maybe there is another reason?

Posted by: The Cabinetmaker Jun 24 2016, 05:04 PM

All the reasons are in the twelve pages of YOUR thread, yet you refuse to acknowledge the obvious? I won't be reading anymore of this thread. I also won't be reading any of your post in the future. By the time you read this, you'll be on my ignore list. Good luck in life. Your gonna need it.

Posted by: Mueller Jun 24 2016, 05:08 PM

Bingo...Porsche is the laziest company in the world, how did they muster the energy to make the /6 models with 5 lug suspension and make the ignition switch in a different location?

They made 3332 914-6 in a period of 2 years.

They made 115,646 /4 bangers.

The /6 models where not quite flying off the showroom floors due to the increased price, for a grand or so more you could have a 911.

The factory obviously saw that there was no reason to put big R&D money into a fuel injected /6. If you notice the /6 stopped in '71.

If the /6 was that popular and a money maker the factory would have spent the money to further improve the product line and it would have had EFI sooner or later just like the 911's which had it beginning in '73

Posted by: jcd914 Jun 24 2016, 05:12 PM

The 914/6 engine is simply a 1969 911 T engine which had already been designed and was in production at the time the 914/6 started production.
They chose a low end 911 engine to avoid the 914/6 out performing the 911.

Jim

Posted by: Mueller Jun 24 2016, 05:15 PM

yep,they actually did have a fuel injection setup they could have used, it was costly for the 911 and it would have been even more money for the 914 due to the lower production numbers. (sure some parts would be the same, but I'm sure there would be 914 specific parts which increases the price)

Posted by: Rand Jun 24 2016, 05:16 PM

Porsche DID go to all the work to inject everything. While they did the fours first, they followed with the sixes. That's just the consumer cars, don't forget the factory race cars WERE using FI back then. And since then, ALL of their cars have been FI. None of them use carbs anymore. WHY?
Please let that sink in before you rephrase the same questions again, or suggest they were lazy or "effing up" or some other ignorant nonsense, again.

Posted by: KELTY360 Jun 24 2016, 06:21 PM

Use the search.

Posted by: OU812 Jun 24 2016, 06:41 PM

Good luck in life, cause I will need it?

You'd swear I said something political.

Come on C maker.....I don't think this is life or death bud.

Don't quite understand the vitriol with the c makers comments.

Last time I checked this was a Forum, and I believe we all know what forum means.

Posted by: Cuda911 Jun 24 2016, 07:44 PM

"Dear Penthouse Forum: I never though I would be writing you! I took my car to the shop to have my EFI replaced with carbs. The mechanic turned out to be a buxom woman!. She asked what I could trade for the work....."

Posted by: 914_teener Jun 24 2016, 07:57 PM

OK.....time out...

Posted by: OU812 Jun 25 2016, 09:37 AM

Posted by: Jeff Bowlsby Jun 25 2016, 10:09 AM

Enough already. I cannot ban you but I can ignore you.


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Posted by: OU812 Jun 25 2016, 11:25 AM