Carbs VS FI, Which is better? Options

[Elliot Cannon]

I'm an old guy and I would say it depends on either how smart you are or how much money you have. I am not smart enough to diagnose FI problems but there are plenty who can. My current 914 stopped on me five times and I had to be towed home each time. I replaced something different each time but it continued to stop. (just like someone turned off the gas) I put a set of del orto 40's on and have not had any problems since. By the way, last year at WCR I averaged 32 miles per gallon. It is a '75 2.0 with 195 X65 tires and runs at 75 mph at 3000 rpm. My original 914, that I special ordered new started having FI problems at about 1979. I put a set of 40 mm webers on it and it still has them and is owned by my friend Bob Scott in Washington. He would not sell me the car back when I wanted to get back in so I found my '75 instead. I do know several owners that have had their cars for many years without any problems. It all comes down to the reliability of the parts on your car and their failure or not. The new FI systems seem to be much more reliable, however, I would be behind the same tow truck if it broke. (IMG:style_emoticons/default/stirthepot.gif) (IMG:style_emoticons/default/confused24.gif)

Nice wheels on that car. Where did you have them done? (IMG:style_emoticons/default/lol-2.gif)

[CrashDown]

Carbs are inherently better. That's why all modern car manufacturers use carbs to generate lots of efficient, reliable power. FI is just a fad.

(Getting ready to pul my SBC Holley 4bbl carb and install a MAF injection system.)

I agree with the first aprt, but you get a (IMG:style_emoticons/default/WTF.gif) on that last part

And the debate goes on and on and on and on ....

I'll take my 27 - 33 mpg and put up with fixing FI. If I want a sucking sound I will record it and play it through my stereo.

You can have your 12 - 17 mpg with carbs.

I have Redline 40's on my 914. i commute 50 miles round trip. When i drive my Subaru RS (non turbo) if i top off on monday i'm filling up thursday.

in the teener with the archaic, fuel wasting carb set up, if I top off on monday, i'm still going the following monday. I belive that's what people call in the judging community, a win.

Carbs VS FI, Which is better?

Yes ... (IMG:style_emoticons/default/biggrin.gif)

I vot this for line of the day....

Well, after buying my 76 914 2.0l with Dell 40's on it in 95, I drove it for three years until I couldn't stand it any longer. Cold starts in Seattle sucked so I bought and re-installed the Djet without any of this Internet help available today. Best decision I made as its been trouble free since but it did have one CHT failure (wouldn't start in the driveway). That was a easy fix so I still don't understand why people say FI is so complicated and hard to fix as there is very few parts, its KISS.

You sir, are a good man. lulz

For me it was easy, 4 injectors at around 100 bucks a peice, plus rebuilding the entire FI system i used to have, that had flat spots, wouldn't idle right, horrible top end was going to be atleast a grand, and that was MY COST at work.

So i just got a set of brand new Redline 40's and it ran me $650..... it runs great, lots of low end, doesn't have flat spots, lots of aftermarket stuff you can do to change them.

if you want to compare the two in terms of colleges;

FI = Oxford, welcome to dullsville
Carbs = Chico state, THE Party school. Now show us your tits....

-Matt

[Bleyseng]

$1000 to rebuild at YOUR COST at your work? Where do you work?

I agree with SLITS and couldn't put up with the sucking sound!
My MPG is around 30mpg on the freeway, in the city its a lot lower as I drive like its a AX reving to 6000 rpms thru the gears without any flat spots or crappy high end. Of course I do know how to tune Djet too by attending classes at the School of DIY.

[Dave_Darling]

I have Redline 40's on my 914. i commute 50 miles round trip. When i drive my Subaru RS (non turbo) if i top off on monday i'm filling up thursday.

in the teener with the archaic, fuel wasting carb set up, if I top off on monday, i'm still going the following monday. I belive that's what people call in the judging community, a win.

Funny, I would have called it "apples and oranges". Since the RS is heavier, has AWD (which takes energy to run), is not noted as a very efficient car, has a 2.5 liter engine, and what, a 10 gallon tank?

Versus the lightweight 914 with a 1.7 liter engine (or is it a 2.0?) with 2WD and a 16-gallon tank.

Tell me why you think that's a valid comparison again?

--DD

[ewdysar]

Carbs are inherently better. That's why all modern car manufacturers use carbs to generate lots of efficient, reliable power. FI is just a fad.

(Getting ready to pul my SBC Holley 4bbl carb and install a MAF injection system.)

I agree with the first aprt, but you get a (IMG:style_emoticons/default/WTF.gif) on that last part


if you want to compare the two in terms of colleges;

FI = Oxford, welcome to dullsville
Carbs = Chico state, THE Party school. Now show us your tits....

-Matt

My first line was tongue in cheek. I was referring to the fact that virtually all new cars are FI, even the high performance ones.

As for my 914 SBC conversion, the holley has been problematic with cold starts, high side load stumbling and elevation changes (regularly more than 5000+ ft differences). I'm switching to the Mass-Flo system that is becoming more common on the big and small block Cobra replicas. Truly self tuning, the only change that I would need for future engine upgrades will be if the engine exceeds the injector's 450 hp capacity. which is past where I plan on taking the car. Easy cold starts, high mileage when driven mildly, ready to run at any throttle setting and unaffected on a quick drive from sea level to 7,000ft. I just don't see a carb being that flexible. When this is done, my only car with a carb will be my Model T. But on that car, 100 year old technology, i.e. a carb, seems appropriate. (IMG:style_emoticons/default/poke.gif)

I don't believe that anyone will consider my car overly sedate (dullsville) after switching to FI. (IMG:style_emoticons/default/driving.gif)

Eric

[jzdu]

If anyone is scrapping their D-jet, I need the auxilary air regulator. Please let me know if anyone wants to sell theirs.

[PRS914-6]

Well, the poll only asks FI vs. carbs so general question gets a general answer, not really 914 but general...

Years ago when FI first came out I didn't understand it.....it was voodoo to me. When I ran into problems I yanked it off and installed carbs. Had them all my life and they were easy to me.

Fast forward 30 years and you couldn't give me a carb.....You couldn't pay me to convert. Now I yank off carbs and install FI. I went all the way the opposite direction where I actually burn my own chips (Chevy) When you can drive down the road running your vehicle on a laptop making changes on the fly you realize the time savings and efficiency. Too lean in one area and you can richen it up with a click of the mouse. Ping in one area, retard the timing in that area with a click of the mouse. Want a faster idle, a mouse instead of a screwdriver! Too lean at warmup, easy to fix....all on the laptop. When you get it perfect, you burn the chip and you are done. It's unbelievable awesome to do tuning this way instead of jet changes and recurving distributors. Those are the positives. The negatives are one....a steep learning curve. Modern day electronics pretty much diagnose a bad component on their own (not our 914's)

The negatives of carbs.....

When the air/fuel mixture goes around a turn in a manifold it has a tendency to separate
Gaskets dry out when it sits
Warm up is problematic
Mixture gets heated in manifold
Big cams , their low vacuum and intake reversion drives you nuts
Don't adjust for altitude
Not accurate across the temperature spectrum
Don't adjust for a hot or cold engine or air temp
Float bowls are vented to atmosphere causing sludge when sitting
Lots of work to adjust for engine changes
Ice up without "preheat" air

A carb is perfect on Fred's car.....Personally, I would leave it there (IMG:style_emoticons/default/biggrin.gif)

[GeorgeRud]

(IMG:style_emoticons/default/agree.gif)

though I love the look of my Webers, PRS914-6 hit it right on the head with his comments.

[stugray]

Just curious then:
Why was the 914-6 GT racing car sold with carbs?

AND won 1st place in GT class at 24 hours of LeMans in 1970?


(IMG:http://www.914world.com/bbs2/uploads_offsite/www.maxted-page.com-10819-1315333935.1.jpg)

Musta been because FI was better, but they wanted the challenge of racing with inferior equipment.....

Just ONE of the answers is:
Because the carbs give an expert infinite (almost) adjust-ability.
But with 70s technology FI, you get what you get.
Now if the Poll had mentioned modern FI like the megasquirts, the FI wins hands down.

The stock FI on the 914 is an analog computer. Unless you know how to change the gains on Op-Amps, then you cannot change much at all.
If you increase displacement or change the cam you are stuck.

Stu

[FourBlades]

EFI for a daily driver because of its sealed fuel systems that don't suck up water like carbs do. Florida is especially bad for this problem with its constant high humidity.

E15 is coming and will make fuel problems worse for daily driver cars with carbs.

I would like to move to EFI for my driver 914s and keep carbs on my 914 IMSA car in which I will run race fuel from sealed containers. Expensive, but you know what you are getting and it will not turn that many miles per year.

John

[Robert21]

It will be eight years with my 914 2.0 Had troble with FiI at first, until got new wires and brain , Have not had any ploblem since then. that was 7 years ago. If works leave it alone. Run every time. no tow trucks. Go 80 mph down the fwy no problem.

[gil914]

F.I. any day. My WRX has fully programmable stock and a programmable TEC-II (redundant F.I. no less) switch back and forth as needed. My 914-6 has programmable Autronic with individual stacks. The new 2.0 has Webers but I'm trying to find a working stock 74 DJET. If not I'll fake it and put a Megasquirt hidden somewhere.

The tripple and double webers sitting in the garage sure are pretty though....

[reharvey]

[quote name='gil914' date='Feb 15 2012, 01:58 PM' post='1625932']


My D/jet 2056 with Webcam # 73 runs great but you need to know how to tweek the FI so it'll run well. I'm sure it's the same with carbs. So----maybe it's all in what a person knows how to work with. Ray

[Dave_Darling]

Just curious then:
Why was the 914-6 GT racing car sold with carbs?

Because that's what the street car was homologated with. If they could have put MFI on the motor and stayed within the rules, I'm pretty sure they would have done it. Most of the factory's full-tilt race cars used MFI at that time, and for quite a few years later.

--DD

[914_teener]

Just curious then:
Why was the 914-6 GT racing car sold with carbs?

Because that's what the street car was homologated with. If they could have put MFI on the motor and stayed within the rules, I'm pretty sure they would have done it. Most of the factory's full-tilt race cars used MFI at that time, and for quite a few years later.

--DD

Dave....homo what?

Nice.

Injection is great....it's the wave of the future don't ya know. My teener runs great with it. The car was homolagated with it...them German egeneers knew what they were doing.