I currently have an edelbrock proflo system on my 383 in my 76 vette and would like to put it in a 427 or 454. An email from Edelbrock indicated that the injectors would need to be heavier, but otherwise it should work unless I get a higher lift cam, then I would need a chip. The thing that I am worried about is the 'global fuel' modifier on the proflo system. I have to increase it to +6% for the 383 and I think it only goes to +9%. It doesn't make any sense that I wouldn't need to modify the base fuel map to accomodate a jump to a 427 or 454.

Also, Technoresearch.com supposedly has software that just came out that allows a higher % of global fuel increases. I have emailed them and they just sent me a weblink, so I still have some work to do.

Anyone know anything about this stuff??

Thanks,

 

I don't know much about the ProFlo system but generally speaking given two differently sized engines but say similar in mods ( ie a crate SBC and a crate BBC) if the injectors are sized to the engine then the fuel tables will look the same.

 

OK thanks, that is some support for the info Edelbrock sent me. I have a year or so and want to do this right and don't want to save up another 2-3k for a different fuel injection system.

 

I'm not sure about the Ed Proflow system, I'm running the Holley CMD 950 on a 413 SBC and use 36lb/hr injectors. I'm thinking about building a 427 sbc as well and would switch to 40lb/hr injectors.

 

The Pro-Flow system is based on a Magneti-Marelli ECM that was used in a Lancia Delta Intregal "turbo wondercar" in Europe. The system is decent enough for the money but tuning is very limited compared to Holley, Accel and othe EFI systems. The Prom Chip contains the "base fuel mapping parameters" and the deviation allowed from the base is limited. There are people out there who can re-write the Prom memory chips besides Edelbrock but, I have never delt with any of them. I installed this system on my LT-1 years ago and because of the manufacturing defects in the EFI ECM ("we test each and every unit") we had to forgo dyno testing of my set-up and it is still sitting in boxes in my attic. I DID prove to Rick Roberts of Edelbrock that he is WRONG! and "each and every unit is tested" is an out and outright LIE! My Magneti Marelli ECM had missing grounds on 3 out out of 8 injector drivers and when I questioned Rick Roberts on this apparent problem, I was told to just "run the unit, they are all factory tested". My ECM set the injectors on full dwell (turned on, spraying fuel) and hydrauliced my LT-1 on the engine dyno! I went through HELL to get a repalcement unit and was given several PROM chips as a appology for their lack of proper testing and failure to service their product after sale. I know things have changed by now, but back then, Edelbrock had no spare parts on hand and good product knowledge was severly lacking. I can tell you that the "trick" ignition amplifier box is nothing more than a "7 pin" GM HEI ignition module and Micro Switch make the distributor sensor for the ECM. The Idle Air Controller is from a Ford (a big P.O.S. compared to the GM IAC) and the other sensors are mainly GM "spec" sensors (from TPI era EFI units.) Hollet does a MUCH better job of providing tech assistance and support for their EFI computers and while they are crude "batch fire" units they are better in execution/tuneability than the Edelbrock EFI units.

 

OK thanks for the info, that is helpful. I am probably stuck with this EFI system if I have any chance of making it work as these things are expensive. Regardless, I have had this since '92 and have put about 15k miles on it with the 383 and it h as run perfectly, never a single problem. I guess I just got lucky, but I am very happy with it.

It looks like I need at least 40 lb injectors for the 427.

Anyone have any idea what a sb 454 would need for injectors?