Why EFI?, maybe excellence was expected and they came as close as they could.. Options

[SirAndy]

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. :-)

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 ...
(IMG:style_emoticons/default/WTF.gif)


I think you're really grasping for straws here ...
(IMG:style_emoticons/default/rolleyes.gif)

[veekry9]

BMW-X6M

What kind of carb yuh runnin?
https://www.google.ca/search?q=setting+carb...DmZLsrOniHBM%3A
https://www.google.ca/webhp?sourceid=chrome...ing+weber+carbs
https://www.google.ca/webhp?sourceid=chrome...0fuel%20mixture
https://www.google.ca/search?q=constant+vel...vyNyXRYfd_WM%3A
https://www.google.ca/search?q=constant+vel...SWHBgEQ_AUICCgB
https://www.google.ca/search?q=su+cv+carbs&...ygA&dpr=1.5
https://www.google.ca/webhp?sourceid=chrome...on%20cv%20carbs
https://www.google.ca/search?q=mikuni+cv+ca...UWDAQcQ_AUIBigB
https://www.google.ca/webhp?sourceid=chrome...retor+vs.+slide
https://www.google.ca/search?q=kendig+const...SgA&dpr=1.5
https://www.google.ca/webhp?sourceid=chrome...ator+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
(IMG:style_emoticons/default/biggrin.gif)
https://www.sema.org/sema-enews/2011/19/cre...dig-passes-away
(IMG:style_emoticons/default/huh.gif)

[Darren C]

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.

[Tom_T]

Did Porsche eff up?

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

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

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

WHY DID THEY DO IT?????

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.

Well, with 7 pages of replies, you've certainly opened up a can of worms! (IMG:style_emoticons/default/biggrin.gif)

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!! (IMG:style_emoticons/default/dry.gif)

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! (IMG:style_emoticons/default/beerchug.gif)
Tom
///////

[Gunn1]

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

[KELTY360]

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

Are you still implying that someone did eff up? (IMG:style_emoticons/default/chair.gif)

Wake up and smell the hydrocarbons. (IMG:style_emoticons/default/slap.gif)

[DBCooper]

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

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:

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

[Gunn1]

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

Are you still implying that someone did eff up? (IMG:style_emoticons/default/chair.gif)

Wake up and smell the hydrocarbons. (IMG:style_emoticons/default/slap.gif)

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.

[Gunn1]

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

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:

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

Are you drinking again?

[jd74914]

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.

[914_teener]

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.

[914_teener]

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

[Gunn1]

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

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

[MarkV]

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

1. Reliability

2. Simplicity

3. The ability to use a non Bosch distributor

4. The look

5. The sound

[Gunn1]

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

1. Reliability

2. Simplicity

3. The ability to use a non Bosch distributor

4. The look

5. The sound

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........

[DBCooper]

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

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:

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

Are you drinking again?

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?

[veekry9]

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

https://issuu.com/contact.magazine/docs/alt...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.
(IMG:style_emoticons/default/biggrin.gif)

[SirAndy]

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

1. Reliability

2. Simplicity

3. The ability to use a non Bosch distributor

4. The look

5. The sound

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? (IMG:style_emoticons/default/wacko.gif)

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. (IMG:style_emoticons/default/driving.gif)


(IMG:style_emoticons/default/bye1.gif)

[Bleyseng]

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

1. Reliability- Damn I was always fooling with the Dells

2. Simplicity- Yep, simply refused to start in the cold

3. The ability to use a non Bosch distributor- why?

4. The look- well maybe

5. The sound- yes, that loud sucking sound so I couldn't hear the passenger talk....

[914_teener]

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

1. Reliability- Damn I was always fooling with the Dells

2. Simplicity- Yep, simply refused to start in the cold

3. The ability to use a non Bosch distributor- why?

4. The look- well maybe

5. The sound- yes, that loud sucking sound so I couldn't hear the passenger talk....

Fixed it.