C-4 Engine questions
Thread Starter
Intermediate
Joined: Oct 2013
Posts: 26
Likes: 0
From: Vancouver WA
C-4 Engine questions
I acquired a 1996 c4 convertible this spring and would like some direction as to improving performance without removing engine from car LT-1 w/91K on it
Last edited by captgarys; Oct 12, 2013 at 09:42 AM. Reason: Increase info
Melting Slicks
Joined: Feb 2008
Posts: 2,384
Likes: 56
From: West Chester PA
St. Jude Donor '09 thru '25
You can do plenty without pulling the engine...better air intake, Long tube headers, cat back exhaust, roller rockers & springs, change rear; lots of threads on these subjects if you do a search.
Also with a little teardown....new heads or have yours ported, port intake and throttle body.
Figure out how much you have to spend. Then do some reading, decide if / what you can do yourself then post up. You'll get tons of opinions .
Also with a little teardown....new heads or have yours ported, port intake and throttle body.
Figure out how much you have to spend. Then do some reading, decide if / what you can do yourself then post up. You'll get tons of opinions .
Race Director
Joined: Jan 2005
Posts: 10,641
Likes: 13
From: Slidell Louisiana
LT1 exhaust flows pretty good and you won't find much bang for the buck in changing it with a stock engine, same with the stock intake manifold.
If you have 2.59 rear gearing 3.45, 3.56 etc will make a huge improvement IRT acceleration.
However, for real power improvements on a LT1 require more than bolt ons IE Head, cam, headers etc.
(check out advanced induction if you want some proven reliable LT1 power)
FWIW I'm still using the factory cat back (collector pipes into high flow cats with out the resonator)on my 95 and we've had it on the dyno with a pressure gauge hooked to the wide band bungs in the header collectors IOT see if it was time to upgrade the exhaust and even on a 7300 rpm pull there was no excessive back pressure. I'm sure that some day I'll mod enough to have to install the 3" BB system that's been in the attic for more than five years.
If you have 2.59 rear gearing 3.45, 3.56 etc will make a huge improvement IRT acceleration.
However, for real power improvements on a LT1 require more than bolt ons IE Head, cam, headers etc.
(check out advanced induction if you want some proven reliable LT1 power)
FWIW I'm still using the factory cat back (collector pipes into high flow cats with out the resonator)on my 95 and we've had it on the dyno with a pressure gauge hooked to the wide band bungs in the header collectors IOT see if it was time to upgrade the exhaust and even on a 7300 rpm pull there was no excessive back pressure. I'm sure that some day I'll mod enough to have to install the 3" BB system that's been in the attic for more than five years.
