'97 Vortec to Holley EFI

[wyn97]

I am eyeballing a future project involving a 4bbl L31 intake and a Holley Terminator 4bbl kit with transmission control, and even adding in the Holley ignition parts if I don't feel like integrating the Vortec distributor. That should take care of the engine and the transmission control. What I don't know is what I'd lose if I pulled the existing ECM out of the truck in terms of body control etc. I assume not much, but hoping that the more familiar parties here could shed some light on what I'm overlooking before I start acquiring parts.

I'm in no hurry, the motor is relatively freshly rebuilt, sat at my parents place after we rebuilt and swapped in a 5.7 from a '97 burban and was only used for truck stuff for the last 6 or so years. I've recently re-acquired it and will be using it as my daily. I can hear it now, "It works, don't fix it!". I can't leave well enough alone. Plus, I have experience with Holley EFI and would like to fiddle with my own project for once. Maybe someone with a lot more sense will talk me out of it.

 

[The_Family_Tahoe]

I'm not the guy to talk you out of it. I think you would be money ahead though if you did the 0411 pcm swap to the existing combo. With the mpfi conversion you can swap to larger injectors in the spider and have all the tunability of the 0411 to fuel and manage any combination of cam, heads, exhaust, boost, and gear ratio.

 

[LC2NLS6]

I have two Holley efi vehicles...Sniper was cool and all as an idea when I tried to do a cam swap on the cheap, but that snowballed quickly into a full engine rebuild, but the termi is the way to go. I run an HP ecu on a custom made harness that was plug n play by my engine builder for the Turbo Buick at cruz performance in Tampa FL. The terminator, its 3200-3500 iirc, then you have to get the adapters etc for everything, could be 5k by the time you get done with it for no real gain in performance if you aren't going big cam and better heads that can take the lift, what can the vortecs handle, maybe 450 lift and have press in studs that can pop if run high spring pressure, which is not a lot.

 

[wyn97]

I have two Holley efi vehicles...Sniper was cool and all as an idea when I tried to do a cam swap on the cheap, but that snowballed quickly into a full engine rebuild, but the termi is the way to go. I run an HP ecu on a custom made harness that was plug n play by my engine builder for the Turbo Buick at cruz performance in Tampa FL. The terminator, its 3200-3500 iirc, then you have to get the adapters etc for everything, could be 5k by the time you get done with it for no real gain in performance if you aren't going big cam and better heads that can take the lift, what can the vortecs handle, maybe 450 lift and have press in studs that can pop if run high spring pressure, which is not a lot.

I'm pretty familiar with the products, worked on racecars with everything from snipers to dominators. Just never had my own. I'm really just looking at what electrical hurdles I might run into with the truck and the dash, that's what I don't know about. What things I'm going to run into tearing the PCM out is what I have no idea on. I don't plan on doing any major changes to the motor beyond a cam way down the road, so maybe there's no point anyhow. I just like the idea of tuning my own stuff.

 

[L31MaxExpress]

0411 swap plus HP Tuners is far cheaper than the aftermarket EFI garbage. 98+ black box can also be tuned with Hp Tuners.

Currently have a ported stock intake with a 48 lb/hr spider on my ~500 hp 383. Gotta love being OBD2 smog compliant. I have not started power tuning it yet, still running a safe rich afr and low timing values and shifting at ~5,000 rpm, but the 383 is a beast. 0-60 in about 6 seconds in my 6,500 lbs Express van. Accelerates like you were rear-ended by a freight train compared to the stock L31. On E85 with the fuel dialed in and more timing as well as spinning it higher it should dip in to the mid 5s 0-60.

You must be registered for see images attach

You must be registered for see images attach

 

[The_Family_Tahoe]

@L31MaxExpress I didn't know of any examples of an 0411 swap with larger injectors in an MPFI spider. Good to know my theory is sound. Can you share your 383 specs? Specifically what cam and heads? How did you pass smog? In Texas they require an obd2 readout, but no sniffer. Can I tune the 0411 not to throw codes with a cam? I've been thinking a 212 to 218 intake duration at .050. Let me know if there's a better thread for all these questions. Nice build, and thanks for the pointers in my thread around installing stock front springs in the tahoe.

 

[Awest623]

0411 swap plus HP Tuners is far cheaper than the aftermarket EFI garbage. 98+ black box can also be tuned with Hp Tuners.

Currently have a ported stock intake with a 48 lb/hr spider on my ~500 hp 383. Gotta love being OBD2 smog compliant. I have not started power tuning it yet, still running a safe rich afr and low timing values and shifting at ~5,000 rpm, but the 383 is a beast. 0-60 in about 6 seconds in my 6,500 lbs Express van. Accelerates like you were rear-ended by a freight train compared to the stock L31. On E85 with the fuel dialed in and more timing as well as spinning it higher it should dip in to the mid 5s 0-60.

You must be registered for see images attach

You must be registered for see images attach

A little off topic, but are you using the wynjammer injectors? I've been using the 48lbs from them but haven't been able to find accurate specs to plug into the tune (flow rate, voltage offset, etc.). Makes tuning not quite as fun

 

[Awest623]

@L31MaxExpress I didn't know of any examples of an 0411 swap with larger injectors in an MPFI spider. Good to know my theory is sound. Can you share your 383 specs? Specifically what cam and heads? How did you pass smog? In Texas they require an obd2 readout, but no sniffer. Can I tune the 0411 not to throw codes with a cam? I've been thinking a 212 to 218 intake duration at .050. Let me know if there's a better thread for all these questions. Nice build, and thanks for the pointers in my thread around installing stock front springs in the tahoe.

You can tune the 0411 to do about anything you want.

 

[The_Family_Tahoe]

@Awest623 how do you like the cam and heads on a stock shortblock? It looks like a great truck and towing combo with the whipple. Any dyno or track times with the new combo? How close is your tune without the injector specs? What would you recommend for someone about to attempt something similar?

 

[Awest623]

@Awest623 how do you like the cam and heads on a stock shortblock? It looks like a great truck and towing combo with the whipple. Any dyno or track times with the new combo? How close is your tune without the injector specs? What would you recommend for someone about to attempt something similar?

I love it, not a whole lot of top end but she'd pull a house. Putting off any dyno time until I put an intercooler on it. It does pretty good even without the correct specs, just some tuning issues that I haven't been able to fully resolve. I.e., she doesn't like hot starts or idling for long periods of time. I think it's mostly an IAT sensor placement issue but incorrect injector data definitely plays into it.

My best advice would be to practice tuning the stock engine first until you have a basic understanding of how it all works. There's a lot of different tables to mess with, but most of them don't require adjustment to get it running. Learn the basics, once you have them mastered you can start messing with the fancy stuff.