Modifying an Edelbrock Proflo EFI for sb427

[CorvetteDave01]

Hey all, I'm new here and hoping to tap into some EFI knowledge as I don't have much. Any help would be greatly appreciated.

I have a '76 vette that I am in the process of putting a sbc 427 in (Dart Little M, scat crank/rods, AFR 210 Elim heads, 10.5:1 cr: solid roller comp cams 630/630 (with 1.6 ratio rockers) 252/258 dur @ .050 and 111 LS). I had a 383 with an Edelbrock proflo EFI system in the car for about 14 years or so and am in the process of modding it for the 427. Below is what I have done so far.

Contacted Edelbrocks efi tech line multiple times to get where I am. This is a speed density, MAP, MAT type system. I need 10" vacuum to keep it working according to Edelbrock, possibly can go down to 9" with proper tuning. 1000 cfm throttle body has a unique bolt pattern and throttle position sensor, so I can't get a different throttle body, might be able to make a stepped adapter and use a different intake, but I will use my modded intake for the time being as it is already in process.

EFI mods so far
1. 48 lb Venom high impedance injectors to replace the 28 lb injectors
2. Victor Jr. intake us being worked on now because the ports aren't tall enough to match/seal with the AFR 210 heads. They are welding a bead on each runner and then will machine and port the runners and plenum.
3. Debating on a different fuel pump. Edelbrock indicates the 3500 system pump is good for 625 hp, but someone posted that I need fuel pump flow 20%-50% greater than the injector flow? 50% would be about 566 lbs/hr.
4. Got a longer duration base chip from Edelbrock.
5. Thinking about buying the winproflo software for $139, so that I can program it on a laptop. Anyone use this before?

Will have around $1200 in mods if I get the fuel pump, so still way cheaper than a new EFI system.

Thanks for any help!

[Fuelie Nova]

I have run and modified a lot of edelbrock efi units. I think you will be disappointed in the end. You are taking the 3500 to levels is was not intentionally designed for.
I have used the proflo software and the only real advantage it has is data plotting and being able to look at the entire data table, you can also print out the setup.

I can post more tomorrow but if it were me I would bite the bullet and swtich to the Holley commander 950 ecm and add the wideband option (or XFI or Gen7). You will be much happier in the long run.
Tg

[CorvetteDave01]

I suspected as much and yet, I am stuck here for the moment due to budget constraints. The winproflo software indicates you can make 'greater percentage' changes? What does this mean?

How hard would it be to get something like the FAST, Lingenfelter or Megasquirt system to work with my existing hardware?

[Fuelie Nova]

I would have to look back and check. I don't run the eldo setup anymore however I remember that some parameters the eldo would limit how much you could increase (or decrease). I think the global fuel modifier was one. The winflo software does not limit how much you can change.

One alternative might the the Holley commander 950 setup. It is reasonably priced and easy to tune. I ended up ebaying my eldo ecm, display module etc. and converted to the Holley setup. Still using the eldo intake, throttle body, injectors etc. Had to convert the IAC ($100), it was worth the conversion.

Tg

[CorvetteDave01]

Thanks for the Holley info TG. I may end up doing that eventually, I think at this point, I need to see if the thing is going to run as is first and then decide.

Did you need a new wiring harness or just the ecm for the Commander 950 setup conversion? How much did that run you?

I also talked to an Accel DFI dealer and he indicates I could convert with my existing hardware no problem, but I would have to stick with batch fire if I didn't add a crank sensor and continued running the hall effect distributor. These are $1600+ unfortunately.

[Fuelie Nova]

You would need a new wiring harness. I think the ecm with all the sensors and wiring harness is around $950.
I sold my used eldo stuff for $525 on ebay... was a cheap way to step up.
Tg

[CorvetteDave01]

OK TG, again thanks. I'm wondering how hard it would be to convert my wiring harness? May do what you did and sell the Edel. ECU and harness.

I'm also thinking about converting to a megasquirt system, looking into it as well, but I'm going to see if the thing runs fine as is first.

[ErikSOCAL]

check this out.
ps - don't let him see you sold the harness for $525. I bought his for much less to mess around with a pro flo manifold I had found here. Also thought about doing the megasquirt ecm using the edelbrock manifold. My car isn't beyond the systems limits (@420hp) so no point to change yet.

http://www.edgesz28.com/edgesz28/fuel.htm

[Fuelie Nova]

Ya... I have corresponded with Ed several times. He is a great hot rodder. I can guess what you bought his stuff for because I came close to buying it from him.
The stuff I sold for 525 was close to as good of a deal... it had the mallory dist for the eldo setup, win proflow software. Different software for the ecm and many spare parts

The eldo is one reliable setup, I just switched from the commander 950 to an XFI. Really happy with the XFI setup.
Tg

[ErikSOCAL]

TG, I'm glad to hear you think the edelbrock setup is reliable. Lots of people seem to discount it but I think if you know your engine and its within the parameters that the system will support, its one of the less complicated ones. Plus I'm a beginner so this is right up my alley.
Not to thread jack Dave's post but what are either of your thoughts on running fuel lines. I'm thinking teflon lines all the way vice a combo of teflon and hardline. the section I would run the hardline would already be in or along the frame rail so I think to save myself some headache bending and interrupting the line for an inline filter and merging the different lines, I'll just run teflon the whole way.

[CorvetteDave01]

I got the motor in and barely running with the Edelbr proflo setup (with the upgrades). It runs extremely rich, just ran it for about 30 seconds then turned it off cause I don't want to damage the motor. The idle rpm won't budge when I try to calibrate it, so I think the ecu isn't able to read the MAP sensor. Don't think this setup is going to work at all.

I ran braided -8 AN feed and -6 AN return lines with an Aeromotive A1000 pump, Peterson pre-pump filter (stainless 100 micron with -8 AN fittings) and a JEGs post-pump, think it's a 10 micron filter with -8 AN fittings. Had a sump welded into the tank too.

Thinking more toward the Accel, FAST or Holley ECU's at this point. I just think the Megasquirt is going to be too much for me, everyone says it involves a LOT of time to get it right, more so than the other systems.

Going to have to decide something this week, cost is definitely an issue, might be able to squeeze 1500 into it, 2k is too much.

[Fuelie Nova]

I haven't tuned the eldo setup for a long time but... are your throttle plates set correctly? Also you can go into global parameters and reduce the amount of global fuel by a given percentage, make it less (You can even go negative if I remember correctly). That along with dropping your idle enrichment should help get it idling.
Are you able to check you engine vacuum at idle with a gauge? If so what is it? What does your eldo read for vacuum at idle? Is it close to matching your gauge?
Just some thoughts for you.

Tg

[CorvetteDave01]

I didn't try to go negative on the global fuel mods, guess I can try that. Vacuum is about 4-5" @ 750 rpm per the proflo module, but it bounces around quite a bit. I'll see what I can do with it, just don't want to melt pistons playing around with it and leaning it out too much.

[Fuelie Nova]

Yep. the eldo does not do well with vacuum below 10
Tg