spedaleden

I have a 81 with carb and Vortec Heads. I know Edelbrock and Holly make EFI kits. Are they reliable, do I need to change stock tank, do I need to run new fuel lines. Hood Clearance issues. With current motor and stock air cleaner (Fast burn w performer intake & Edelbrock 1411 carb) I rub the hood slightly.

Just trying to figure out what I am getting into.

Current motor

Cookwithvette

I have the Holley Commander 950 setup with Wideband O2. I believe the Holley setup comes with wideband by default now.

I'm using one of those bicycle seat air cleaners, I believe you can use a drop-base cleaner if you cut the top of the linkage but I couldn't tell you about the stock air cleaner. Also, I think our hoods are different.

1975 was one of the odd years for Corvette gas tanks so my experience there won't be terribly useful. If you have a bottom draining tank you are in business. If you can mount a pump in the tank, you are good to go. Otherwise you might want to consider going the route I went and get a sump welded onto the bottom.

It has been reliable.

Lines... not sure what size lines your car has but I think the minimum feed line size is 3/8 and return is ...1/4? I ran braided SS hose (-6an) but that means finding a fuel filter (expensive). If you keep the stock steel lines you will need to replace any rubber on the pressurized side of the system to cope with the higher pressure.

It is a pretty good setup and once it's dialed in it will start and run in ANY conditions. Last winter my father came to visit and had never seen the car. It was 5*F and it started on the first crank.

Good luck... sorry I couln't give more specific answers but it is kind of a custom thing. Everyone's setup is going to be kind of different.

spedaleden

Cookwithvette

Thanks for the info. Did you notice more HP with EFI?

shafrs3

Minimum return fuel line size is 5/16" according to holley's instructions. Mine has been reliable too.

spedaleden

Can anyone email or fax me a copy of the installation manual from Holly.

Please advise

shafrs3

You can download it directly from the holley web site, PDF format.

spedaleden

Thanks, I got it. It is cool, but it looks like a project to do over winter.

Cookwithvette

Not really noticable HP increase but Holley claims the ZZ4 picks up about 30 ponies with the swap. Most of that should come from the change in manifold type.

It does behaive differently. It seems a touch softer in lower RPMs but once you get above about 1800 it starts to kick in, past 3000 it really wakes up and hauls to 5500. Before it started to run out of breath around 4800.

Cruise milage hasn't increased either. I believe my TH400 is what's holding me back there.

With the carb... if I drove nicely I got 20 mpg. If I drove hard it was closer to 10-13.

With EFI... driving nicely it's about 20 mpg. Driving hard it's about 17-18.

davidm_comp

I just started putting in a Holley 950 system last weekend. Hardest part so far was removing the existing fuel lines and running SS Braided in stock location. I decided to set the original gas tank aside and put a fuel cell from Summit in. Tonight I will finish up the welding of a cage that encloses the fuel cell and hopefully get the cell mounted in the car. I will be running an external electic fuel pump. As far as hood clearance, the holley tbi aircleaner flange is much lower than my old edelbrock carb, so I can run a taller aircleaner and still be ok.

spedaleden

Sounds good. If you can post as many pictures as possible

Thanks

fl_rider

Doesnt the stock Chevy TBI use a spacer ring for the air cleaner?
Couldnt you use one of those to get the stock height or somewhere near it?

Chris B

davidm_comp

I will have more pics tommorrow, hopefully some with the fuel cell mounted in the car and fuel lines all plumbed up.

spedaleden

I like what I see. Keep the pictures comming.

I found this at Holley. What do you think?




Stealth Ram Multi–Point Fuel Injection System Vortec Engine Applications,
385–480 Horepower Range with 30lb/hr Injectors
Polished Finish

VetteNut72

Just finishing up the harness and sensor installation on my ProFlo EFI system from Edelbrock.

Still have to install the throttle position and MAP sensors.




This shows how I ran the fuel supply and return lines.


I ran the harness through a grommet in the firewall.


Craig

davidm_comp

If I had the money that is the one I would have gone with, but I could not afford it, so I got a 700 cfm tbi kit off of ebay. Also, plan on getting a wideband O2 sensor, everyone I have talked to has said it makes tuning much easiser. You do not need the $800 Holley wideband setup, I went with this http://www.innovatemotorsports.com/products/lc1.php.

burners

I have the Commander 950 EFI on my '78 L-82. The stock air cleaner will clear if you make a small relief in the lower pan for the throttle lever. I suppose you could shorten the lever but it was too pretty for me to cut. I also had to modify the throttle cable bracket to clear the air cleaner but that was a matter of bending it.



I plumbed the fuel pump into the stock pick up and outlet and have had no problems running the tank low or during racing. I had to run a new 3/8" steel return line along the driver's side following the original return.

spedaleden

Very nice work!

shafrs3

I have a '72 so I don't recognize this area, is your fuel pump located below the fuel tank?

burners

shafrs3, that area may not exist on your car. The pump is bolted to the top of the rear bumper. The shot is looking aft, the hole above is the fuel filler door and the gas tank is removed. Isn't the door located further aft on the '78's and later because of the rear window? The camera is where the gas tank would be. The pump probably sits about mid height on the tank.

spedaleden

Where do you hook up vacuum advance?