I am about to build a 406 that will make about 500-550 hp, either N/A or Procharged. I want to use the Holley Stealth Ram. My dad is going to sell his Z06 and take my Formula (he LOVED his 92 bird!) so I will be starting from scratch in terms of parts that I already have. (And the motor will hopefully go into a 66 or 67 Chevy II.)

I see my most obvious options for EFI being 730 ECM or DFI. I want to consider other possibilities, though:

Why not go MAF? Specifically, why not use a 94-97 LT1 ECM and harness with appropriate (3rd gen?) sensors?

The other thing I thought of is using a Ford 5.0 ECU and adapting either a GM or Ford harness to appropriate sensors.

I need to check at CZ28.com and at the corral to see what the respective EFI setups can handle, but that aside, what do you think? I don't pretend to have much knowledge of EFI, but is there some reason(s) that an LT1 or 5.0 computer would not work? Please help me out!

 

You do have plenty of options and you are going to find starting from scratch can be a pain but it can also reduce costs quite a bit. If cost isn't a concern, consider an electromotive kit. Comes with everything, manifold to ecu, for the swap. This way you don't have to piece it together. The LT1 stuff is a good idea but you have to find a way to run the optispark on the SBC dist. Shouldn't be too hard for a good machine shop to do. If you get that working you can run a coil-near-plug conversion from the LS1. The Ford stuff is a bad idea. I turn wrenches for a living and I just don't see any benefits to the way they do things. Plus you have the TFI ignition to graft anyhow, and their stupid PWM IAC. And the tuners for those cars start at around $500. I'm sure people will say that the tuner does al kinds of magic tricks but you don't need all the silly things they do. It's like buying Win XP when Win95 is more than you need. Honestly, I don't see how everyone running a Ford ecm doesn't switch to GM. The MAF thing I would stay away from too. Why have it when you don't need it. You don't have to worry about plumbing or contamination or anything else. No matter what it'll be a restriction. At least the LT1 ecm can be run w/o MAF so that can still work.

Personally, I have something very similar to what you are building. It's about a 500 HP 400 (dyno'd at 435 RWHP with a carb) when it was running. Damn valvetrain problems have sidelined the engine for a while. Since I have plenty of patience and like the challenge and am eternally low on money, I am building an EFI system for it from scratch. A friend gave me a 305 so it will debut on that and then make it onto the 400 when I get it back together. I have a running total of about $1450 and that includes the following: Accell single plane manifold for EFI with FI rails, SVO inj's, Aeromotive pump and regulator, VSS from JTR, Holley 850 carb converted to be just a TB with TPS and IAC, 730 ecm and harness, laptop (old 475), prom programmer, Tunercat software for prom burning, misc prom burning and scanner electrical gizmos. I'm going to need fuel plumbing but I don't expect that to go over $100 since I already have AN stuff all over the fuel system. Also, a wide band o2 for the DIYWB project. One of the things that shouldn't be included is the TB as this was free. Since I turn wrenches for a living I come into certain things that can be free like that. The carb was beyond frozen and full of rust and of no use to a customer. The TPS and IAC were free too from stuff we had laying around. A lot of the parts were also bought on very good deals. You do have to get things when they are on special, you know. All in all, I expect it to be less than $2K and only because of the high HP application it is intended for. If it were for something in the 350 HP range I figure it could have been done for $500 less. I can't say whether it'll run good on something that high on HP but I believe it will. I seem to recall someone on the GMECM list that had a 430 rwhp car that was running a 730 ecm. Paul Rolico or something? If it worked for him it should for me too. I've been waiting for EFI on this car for like ten years (I originally wanted a Holley 4V tbi, hah!) so I have had plenty of time to look around. Just last year I started collecting parts and more importantly, knowledge. Like I said, I have patience.

 

I checked stuff out at cz28.com. Cost is definitely a factor for me so I'm going to go with the LT1 intake and I want to use a stock ECM. I have two options.

1. Send the intake to John Millican to be modified for a distributor. I would then use a 730 ECM and get into PROM tuning.

2. People at cz28.com are tired of replacing optispark units. An excellent solution is currently being developed. It consists of removing the high voltage section (the cap and rotor, which is the cause of the problems), keeping the optical part (improved housings are currently being developed), and using LS1 coil packs. The stock PCM is retained. This solution is going to be in the neighborhood of four hundred dollars plus another two fifty or so for coil packs.

This is the main thread:
http://web.camaross.com/bb/Forum30/HTML/001074.html

This should come to fruition very soon! You can use a junk yard LT1 intake (with no modification), TB, fuel rails, sensors, opti "core," PCM, and harness. Add in an aftermarket MAF sensor and you have an entire fuel injection system for what, about $1000!!

For the first option, I would need a Millican-modified LT1 intake, TB, fuel rails, sensors, 730 ECM, and harness. If the opti fix turns out to really be $650, there is not that much difference in it and having John Millican mod an intake. Plus, you get more efficient CNP ignition.

I will just have to see what all is involved in tuning the LT1 computer and compare it to tuning the 730. I will have to get all the stuff to tune either as I don't even have a scanner right now.

 

Originally posted by cort351w
I checked stuff out at cz28.com. Cost is definitely a factor for me so I'm going to go with the LT1 intake and I want to use a stock ECM. I have two options.

1. Send the intake to John Millican to be modified for a distributor. I would then use a 730 ECM and get into PROM tuning.

I would definitely consider using a single plane manifold for EFI with the intended HP you plan on making. Since you have to buy a TB anyhow, the price would be about the same and the single plane would have much better breathing.


2. People at cz28.com are tired of replacing optispark units. An excellent solution is currently being developed. It consists of removing the high voltage section (the cap and rotor, which is the cause of the problems), keeping the optical part (improved housings are currently being developed), and using LS1 coil packs. The stock PCM is retained. This solution is going to be in the neighborhood of four hundred dollars plus another two fifty or so for coil packs.

That was what I was talking about in my first post. Bailey eng. already has the stuff for opti to CNP, no need to wait for anything. He also does the GN MAF translator. FWIW, I have a 95 Z28 that has 135K miles on the stock opti with no problems and since I live in tropical weather it has seen it's fair share of rain. Maybe it's something that happens to them when they are repeatedly taken to high RPM levels (6K+) on those seriously modded cars that things start to go wrong. Mine is still stock.

This should come to fruition very soon! You can use a junk yard LT1 intake (with no modification), TB, fuel rails, sensors, opti "core," PCM, and harness. Add in an aftermarket MAF sensor and you have an entire fuel injection system for what, about $1000!!

Well you haven't taken into account what it would cost to machine the opti for use on a SBC. 48 mm TB might be a bit smallish for 500 HP and I wouldn't bother with a MAF but you seem to like the idea. I plan to run SD mode on my LT1 when I get into seriously tuning it and so I can get rid of the stock air filter box. And you might have a tough time getting a junkyard to sell you the stuff since they could make way more cash selling the whole engine. It would have to be a blown engine or something.

For the first option, I would need a Millican-modified LT1 intake, TB, fuel rails, sensors, 730 ECM, and harness. If the opti fix turns out to really be $650, there is not that much difference in it and having John Millican mod an intake. Plus, you get more efficient CNP ignition.

From what I understand there is a world of difference between DIS (waste spark) and CNP so I can imagine what the difference is going from a dist to CNP. There might be another option than trying to run the opti on a SBC and using the Bailey box. You might be able to run the FAST e-dist with a modified dist using a Cadi 4.9 PFI dist that has cam and crank signals. Actually, it's just cam and TDC sensor for SFI identification.

I will just have to see what all is involved in tuning the LT1 computer and compare it to tuning the 730. I will have to get all the stuff to tune either as I don't even have a scanner right now.

Tunercat has def files for either. The scanner for either is free. However, you don't need a prom programmer for the LT1 so that is a big difference. In that respect the LT1 is easier, cheaper.

 

Hector, thanks for all your help so far. I have a few more questions.

I started a similar thread on cz28.com, but I'd like to get your advice also. I'd like to go the CNP route. What do you think of using an MSD crank trigger and cam sync, LS1 coils, and a box to fire the coils that is also compatible with an LT1 PCM.

If I've read stuff on cz28.com correctly, then the Bailey box should work, right?

Also, is the FAST eDist compatible with the LT1 PCM? Is Motec's box?

I like the computer-to-ALDL tuning style of the LT1 PCM and I like that I should be able to set up a CNP ignition. For these reasons, I would choose the LT1 PCM over the 730 ECM.

Also, I like your single plane EFI intake idea. What kind of TB would you suggest--TBI/4bbl-style or TPI/LT1-style with adapter?

 

Originally posted by cort351w
I started a similar thread on cz28.com, but I'd like to get your advice also. I'd like to go the CNP route. What do you think of using an MSD crank trigger and cam sync, LS1 coils, and a box to fire the coils that is also compatible with an LT1 PCM.

The Bailey box works with the opti, I don't think it'll work with the crank and cam synch. That's going to need the e-dist from FAST but the LT1 pcm needs the opti signal.

Also, is the FAST eDist compatible with the LT1 PCM? Is Motec's box?

You're going to have to call FAST for the true answer to that but it is my understanding that it will. I believe what it does is intercept the timing calculation done by the ecm while sharing the cam and crank signals. However, this would mean you would need to run an opti *AND* cam and crank signals for it to work with a LT1 ecm although not the case with aftermarket ecms.

I like the computer-to-ALDL tuning style of the LT1 PCM and I like that I should be able to set up a CNP ignition. For these reasons, I would choose the LT1 PCM over the 730 ECM.

The problem is using the opti with the LT1 pcm is a must. Have you considered building a LT1 instead of the SBC? I think you could get to use the CNP with a 730 with the crank and cam signal you mentioned above. But you should call FAST for the final answer to that, don't take my word for it.

Also, I like your single plane EFI intake idea. What kind of TB would you suggest--TBI/4bbl-style or TPI/LT1-style with adapter?

I would suggest a free one like this. With the venturis taken out (not hat 850 Holley's have much venturi) it should flow the 1000 cfm most aftermarket units claim.

 

I run lots of Bailey stuff on my car, and every little item has performed flawlessly.
I'm also running an eDIST. With the eDIST you have to fab up the whole harness, and it takes time and effort.
Bob's stuff has always been basically a drop in.

Using the 95 LT1 PCM, 8051, is niceeeeee.
the CNP adds up thou.

The 730 is a work horse thou.

 

Thanks for the information! Because I already have a thirdgen and because of the cheaper cost to build a fox body, I'm building an 88 Mustang coupe. It can't possibly hold a candle to my Formula in terms of looks, but will sure move when I get done. I'm going to build a 347 (or maybe of 408) N/A to about 500 hp. Down the road (more $$), I'm going to procharge it. Maybe I'll also look into the CNP ignition on it down the road, but right now I'm just going to stick with the basics.