FAST EZ-EFI

http://www.compperformancegroupstores.c ... EZIEFIKits

Anybody have any experience with this? They claim that it self learns, so there is no programming.

I've asked alot about this, it's only a 4bbl setup, they don't have an option for a 2bbl setup. and even with the alum head and 4bbl intake I fear it would be too much air flow, even tho it learns I have fear for our SMALL engines... bigger say a 300ci I could see it being usable

It's not like a carb, so it's not a question of too much air, it's a problem of too much fuel.

Air flow on a carb is important because you need to achieve enough velocity and pressure drop past the boosters and thru the venturi to draw and atomize the fuel. Go too big, and the airflow is too slow to work. With injection, air velocity and internal pressure is no longer as important, so as long as you can control the rate of opening on the throttle blades, you could put a 1000 cfm unit on a 200 cube engine!

But these throttle body systems only have four injectors and if they size them to meet the needs of a 500 hp engine, chances are you won't be able to get a small enough pulse width to idle it properly on a 200 cube, 100 hp engine. Mid range power delivery will probably suffer too.

Holley makes a 2bb avenger efi unit that is good to 260 hp, it would probably be perfect for our little sixes.

yeah, but I have heard tunning horror stories from guys that run the dyno... the cheaper once @ 1k don't tune well, and the 2k ones don't tune enough... but that's word of mouth and I have'nt seen anyone run it.

Probably the most cost effective way to put EFI on a 200/250 would be to use the GM TBI system with a 1227747 ECU.

The 2bbl from a 4.3 would be close enough to the HP of either one that you could get it tuned to run well. The duraspark distributor can be modified to lock the advance, delete the vacuum advance, and hooked to a GM 7-pin ignition module for timing control.

Use a 87-91 GM truck junkyard harness, add the coolant, knock, and MAP sensor. Discard the wiring for the EGR, torque converter clutch. You can add the A/C, vehicle speed sensor. You would need an EFI fuel pump and return line.

A stock 4.3 chip would probably get the engine running and might actually run well.

They toss these things onto almost everything and they seem to work well. I've seen one on a flathead V8, a Chevy inline six, a corvair, and all kinds of other oddball engines.

Two points of note :

I've read an article recently in Modified Mustangs and Fords where they installed a 2v Holley Avenger TBI on a 289. They did not use anything to control the ignition through the Avenger as they retained the use of the previous distributor for the purpose of this being a carb to TBI comparison with no other significant changes. They reported no issues with tuning and only good results. Though a 289 is clearly a larger engine than our small sixes, I suspect we should have little to no trouble utilizing it since it's rated max HP range is in the upper realm of what is achievable with a N/A 200.

Also, listed on the Summit site is a FAST EZ-EFI conversion designed for early L6 Jeeps, specifically for the 4.2L sixes. This is designed as a retro-fit, fuel-only system. It is a 4v system and I'm not certain if it is of a 4150 pattern. Regardless, it seems like an option better suited for a CI head and intake, unless a very custom adapter is made. Being it's sized for 4.2L sixes, it seems like a very reasonable option, more so than the "universal" ones that are all sized for performance oriented V8's and strokers.