Carbs or EFI?

[L88 crazy]

I have a 72 Vette that I want to modify but I have hit a snag. Should I stick with a carb or go high tech with eletronic fuel injection. I like the idea of more power out of every air fuel charge with the more efficient EFI but I have heard that it adds an eletronic whirring to the exhaust. To me nothing sounds worse than a 427 BBC with side pipes with an electric whirring noise like stock exhaust C5s do. A carb is simpler compared to an EFI system in terms of setup. In a carb installation you set it on the manifold, you run the fuel lines, and you set the air fuel ratio and that's it correct? On an EFI you have to splice in the computer module, mount the module, than put on the manifold and setup the air fuel ratio right? Which is the best of both worlds in terms of ease of setup and tuning?

 

[lone73]

carb or efi

I put F/I on my 73 about 2 years ago. Its an Accel computer and harness with a Street & Performance intake manifold and Ford 24# injectors. Now that I have it in place it's very easy to change the tuning with a laptop. Knowing HOW to change the tuning with the laptop is the real rub though. In order to get the most out of it you just about have to have it tuned on a dyno.

As for the whirring noise, the only time I've ever heard that coming from a car is on mine due to the external tank mounted fuel pump.

If you go with F/I I strongly recommend you get a setup that allows the computer to mount under the hood. Going through the firewall with a harness or two makes the switch a lot more messy. My Accel ECM is behind the passenger glove pocket thingy. It was a REAL PITA to get it all in there. It is the older 6.0 ECM. I believe the newer ones mount under the hood now. More $$$ though.

That's my $.02 about it...

good luck.

 

[bossvette]

I have a 76 with a modified TPI controlled by a Holley Commander 950 ECU the only noise I hear is from my electric fan and a little whirring from the tank mounted fuel pump.
it is not a real hard conversion for someone with mechanical and electrical experiance working on your own car. The tuning is done by laptop and driving around and making changes. I plan on putting it on a dyno someday to get the last little bit out of it, but am having too much fun driving it now:J

exhaust sound

 

[MoeJr]

I would stick with the carb. Much easier on the wallet and you can use the money you save for other goodies. Just my .02

 

[M&W's72vette]

Lone 73, what engine do you have and what did the fuel injection do for your mileage?

Mike in Idaho

 

[Jacko]

Well, my .02 cents worth.........
EFI is the way to go for the street, and Edelbrock is #1 (in my book).
I run their Pro-Flo Multi-Point system and it works beautifully.
This is not a THROTTLE BODY, is is MULTI PORT injection. It has a 1000 cfm intake horn.
I added a lot of power and my Vette is as sharp and strong as any street car I have ever been in.
Of course, I also have a cam that works, along with the proper gears.
The right cam is crucial.
The Edelbrock EFI is a Speed Density system. That means the fuel-flow, spark advance and other functions are determined in most part from the critical values of engine speed and intake manifold air density. This density info is gained from the MAP Sensor (Manifold Absolute Pressure)
Accordingly, the Calibration Module displays values in Hg (Inches of Mercury, MV (Manifold Vacuum), since most people are familiar with this measurement as an indicator of relative load; with high vacuum at idle and light loads and low vacuum at heavy loads and WOT (Wide Open Throttle).
This type system is very easy for the layman to understand and it is easy to fine tune. The computer to make changes is a hand held unit and is supplied with the package. It simply sits along side you on your seat. Easy to make changes right there at a stop light.
On a 350 with a few choice mods, figure on over 400 HP. Thats a hell of a bang for the buck. The "buck" is about $2,000.00 for the base setup. That's cheap, (in my book), for the gain in performance.
Now I figure I am pushing close to 500 HP. I have some trick headwork done to my Brodix heads. Serti valve job and port work.
My Vette has run 12.3 @ 107 mph without pushing it too hard.
Now wait 'till I hook up the Nitrous, there is a serious street car waiting to happen and I can't wait to see this thing turn 11's
Jacko

 

[lone73]

Engine size

I replaced my original L-82 with a stock ZZ4 motor, other than the intake of course. My mileage actually went down a bit after the FI install. This is because of tuning I'm sure. I bought a used TB with my intake from S&P to save a little money. Bad mistake. It is junk. I should have sent it back and gotten an exchange but I didn't know better until it was too late. The car stumbles a bit when I take off from a light due to tuning, the stumble is worsened by the sticking TB. I'm pretty sure I'm losing significant gas mileage due to those two issues. I'll get it resolved eventualy though. AS with most folks cars, it's a work in progress.

I haven't tried it but I would think that if you installed a stock GM MAP style TPI on a relatively mild motor with a stock '730 GM computer you would see a decent mileage improvement as well as have better emissions. You would probably beat me in a race as well. I probably should've done that but I just HAD to have something unique. I seem to have a penchant for such things. I get the feeling the S&P intake isn't particularly well suited to the ZZ4's cam. S&P said they had installed it on ZZ4's before with success. I guess that meant the car ran. Ha ha.

Good luck with yours

lone73

PS

Unless you've really got it goin' on with computers, F/I, and cars in general, you probably oughta' listen to MoeJr

David

 

[bossvette]

lone73
I have a couple of used GM 48mm throttle bodies do you need early or late style, make me an offer if interested
Craig sr

 

[lone73]

bossvette'

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