C4 crossfire performance cam & heads
03-13-2018, 11:00 AM
#1
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Location: Cresco Iowa
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C4 crossfire performance cam & heads
Good morning everyone,
I just picked up a 59k mile crossfire vette , working on some cosmetic issues first but am looking into several upgrades.
My question is how far can I go with cam and heads before the ECM has a heart attack ? From what I’ve read this ecm is a dinosaur a one off year and there’s not much or anything as far as programming ect ?
I’m thinking a 270 grind .470 to .500 lift , a set of 185cc 64 cc chamber heads , a set of 1.6 rockers and I’ve read up a bit on the renegade intake ,
Trying to get in that 10.1 compression ( close) with respectable drive ability.
I’d be interested in what others have done ?
Is the Renegade worth $550? Is there a better option?
Thanks in Advance!
Tim
I just picked up a 59k mile crossfire vette , working on some cosmetic issues first but am looking into several upgrades.
My question is how far can I go with cam and heads before the ECM has a heart attack ? From what I’ve read this ecm is a dinosaur a one off year and there’s not much or anything as far as programming ect ?
I’m thinking a 270 grind .470 to .500 lift , a set of 185cc 64 cc chamber heads , a set of 1.6 rockers and I’ve read up a bit on the renegade intake ,
Trying to get in that 10.1 compression ( close) with respectable drive ability.
I’d be interested in what others have done ?
Is the Renegade worth $550? Is there a better option?
Thanks in Advance!
Tim
03-13-2018, 01:35 PM
#2
Zen Vet Master Level VII
In short yes.
I don't know how much money you want to spend or what your goals are but you will pretty much wring everything out of that engine with a good intake (Renegade IS the one) a set of headers with a free flow exhaust and great tune up (bump the timing up as much as she can take).
I've read about heads and cams but can't comment. Not the bang for the buck INHO.
Go to the C3 section and hit up Buccaneer. He is a L83 genius.
I don't know how much money you want to spend or what your goals are but you will pretty much wring everything out of that engine with a good intake (Renegade IS the one) a set of headers with a free flow exhaust and great tune up (bump the timing up as much as she can take).
I've read about heads and cams but can't comment. Not the bang for the buck INHO.
Go to the C3 section and hit up Buccaneer. He is a L83 genius.
03-13-2018, 01:48 PM
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Thanks for the input on the Renegade,
Headers are for certain, as far as spending a boat load on the car , probably would if I didn’t have a bunch of parts already , I’ve always been into dirt track racing and a few different street cars , so over the years I’ve amassed a few extra parts 😎
I’ll message the member you mentioned and pick his brain , the parts I have , in just not sure what the ECM will tolerate, in some of the later model stuff it’s easy to compensate for , but with this ECM from what I’m hearing not so much
Headers are for certain, as far as spending a boat load on the car , probably would if I didn’t have a bunch of parts already , I’ve always been into dirt track racing and a few different street cars , so over the years I’ve amassed a few extra parts 😎
I’ll message the member you mentioned and pick his brain , the parts I have , in just not sure what the ECM will tolerate, in some of the later model stuff it’s easy to compensate for , but with this ECM from what I’m hearing not so much
03-13-2018, 04:35 PM
#4
Team Owner
Pro Mechanic
The ECM can tolerate a LOT....if you "trick it". It can't tolerate (or "adjust") much at all, if you don't.
I had an '83 Trans Am with the LU5; a 305 CFI. By the time I sold it, I'd modified the 305 to run 14.5/95 in the 1/4...no changes to the ECM, then I slapped a 350 in there (ran about the same times)...no changes to the ECM, then I put in a SBC 400, THIS CAM (224/234 @.050, 298/304 advertised and .466/.487 lift) cam, headers/exhaust, roller rockers, ported -and I mean REALLY ported- intake, bored TB's, ported lid, and a host of other little things; it would run low-mid 13's in the 1/4 at that point and still, I was running on the original ECM/tune. So it CAN be done, but it does require fooling around with fuel pressures and timing. One thing I found to be a big help (beyond conventional CFI help) was that I installed a marine TBI fuel pressure regulator, which was vacuum referenced like you see on MPFI engines. That helped cut fuel at idle and made everything work pretty well.
The bottom line; if you're willing to fool around with it, you can make it work. Otherwise, you'll need to change ECM's the tune for your combo.
I had an '83 Trans Am with the LU5; a 305 CFI. By the time I sold it, I'd modified the 305 to run 14.5/95 in the 1/4...no changes to the ECM, then I slapped a 350 in there (ran about the same times)...no changes to the ECM, then I put in a SBC 400, THIS CAM (224/234 @.050, 298/304 advertised and .466/.487 lift) cam, headers/exhaust, roller rockers, ported -and I mean REALLY ported- intake, bored TB's, ported lid, and a host of other little things; it would run low-mid 13's in the 1/4 at that point and still, I was running on the original ECM/tune. So it CAN be done, but it does require fooling around with fuel pressures and timing. One thing I found to be a big help (beyond conventional CFI help) was that I installed a marine TBI fuel pressure regulator, which was vacuum referenced like you see on MPFI engines. That helped cut fuel at idle and made everything work pretty well.
The bottom line; if you're willing to fool around with it, you can make it work. Otherwise, you'll need to change ECM's the tune for your combo.