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Is any one on here running any type after market EFI kit?
I been looking in to putting it on my BB chevy.
I have been looking that this one http://www.edelbrock.com/automotive_new/mc/efi/pf_chevy.shtml
it's the last one on the page part# 3550

The only thing I'm worried about is the cam I have, it's a comp 292 with a 110.0 lobe separation
I don't want a tuning nightmare.
I called Eledbrock about it, when I told them what cam and lode separation they didn't sound to confident about it. They said " it can be made to work" That just sounds to me like a headache waiting to happen.
So my Question is what system are you running and what cam and how is tuning? I'm not wanting to peace a kit together.
Thanks Scotty
 

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Last I heard, Edelbrock was using a very outdated computer to drive their injectors and ignition.

The Holley Commander 950 is much more sophisticated and not much more money. I suggest you look into a Holley-based system.

There are any number of "high-end" systems but they get REAL expensive in a hurry.
 

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There are basically two different approaches to EFI in the after market...

First is the plug and play approach. Here you are just supposed to be able to bolt it on and plug it in and it works. Sounds great but there are some tradeoffs. For example with Edelbrock's version you have to provide them with your engine/application parameters and they generate a pre-tuned ROM for your EFI computer. If you change anything or did not quite get it right then you have to buy another ROM. Not very flexible but then you don't need to know much of anything about EFI either. Think of these as being like a vacuum secondary carb that works well on milder motors.

The other approach is the plug and tune. Here you get a fairly generic EFI computer that connects to a Windows laptop. You run a program on the laptop that allows you to tune and tweak and generally customize system operation to best fit your application. Within this segment there are high end and low end systems. The difference is in the amount of parameters you can tune. Very flexible but you do need to know what you are doing and for some systems may need a degree in EFI. Think of this as a mechanical secondary double pumper carb that works with more aggressive setups.

You will want to look for a system that includes a wide band O2 sensor. This will allow easier and more flexible tuning. Some systems will also allow you to tune to alternative and/or multiple AFRs with a wide band O2. Think 14.7 AFR for cruise and 12.5 AFR with more than x% throttle for example.

You may also need to run open loop at idle due to the aggressive cam. The Accel DFI documentation provides some different tune parameters for bigger cams, thinks like more ignition advance and higher idle speeds. At lower speeds your vacuum can bounce which can drive the EFI computer crazy trying to compensate for what it sees as a changing load. If you can setup the computer for basic alpha-N operation at idle (calculate fuel solely from RPM and throttle position) then you can mask out the vacuum bounce if needed.

One other observation is that none of the EFI systems or kits really cover the fuel system very well. Oh sure they include an inline high pressure fuel pump and the relay and wiring for it. And they will perhaps mention that you need a return fuel line. But nowhere will they talk about the need for a surge tank or baffling or some other solution to make the fuel supply constant without interruptions. This is one area entirely left to the student on all of the EFI systems.

I have had the EFI hardware and been planning on doing the conversion for some time. I picked up an Accel Gen 6 with a big pizza box and spaghetti tube intake that will be tricky to fit under the hood. I am just finishing up the fuel system upgrades at the moment. Maybe someday I might even get the rest of it installed ;)
 

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Steve, good info well stated. Thanks for posting.
 

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Zwede,
Did you notice a change in gas mileage when you installed the FI? Do you have any numbers?

I'm definatly looking at FI for my 402. That and an overdrive trans, but that's another thread :)

Does the Holley system have the feature that allows you to plug in an A/F ratio into the grid and have it read the wideband and do an initial tune. In other words, tune itself?

I tuned a couple of these myself, but I'd like to have those hours back if I can.
 

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What cam are you running, and how do you like your system?
It's a mild custom hydraulic roller. 224/230 with .573/.585 lift. I drive it around town so I wanted mild manners.

Zwede,
Did you notice a change in gas mileage when you installed the FI? Do you have any numbers?
I got 20.7 mpg on the highway. That's with 3.08 gears and a 5-speed turning 2000 rpm @ 75 mph. Car is a 3300 lbs C3 vette (1971). The engine was quite sick at the time though. Later found 4 broken piston rings and tons of blow-by. Since then I've also bumped compression from 8.5:1 to 10:1. It might do better now.
 
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