My new 96 z28
TECH Addict
Joined: Feb 2012
Posts: 2,103
Likes: 21
I hope this works out for you. Seems be to a lot of "unknowns" and quirky information about this car having a supercharger installed.
Only one way to tell, but breathing through stock exhaust manifolds and no intercooler with a questionable fuel system and tune puts my guess where it is. Only one way to find out, take it to the track and see your mph or a dyno pull.
Go get some baselines in now then do it again after you fix that stuff. Then post back and well tell you how to fix it and get the real potential out of it.
Go get some baselines in now then do it again after you fix that stuff. Then post back and well tell you how to fix it and get the real potential out of it.
You might as well go buy some longtube headers right now (and good gaskets) why bother troubleshooting an exhaust leak on POS stock manifolds. A blown LT1 needs to breathe...I wouldn't be suprised for it to pick up 40+ HP with the supercharger factored in. Then look into tuning, fuel system, intercooler/SC upgrades to make more reliable and add HP. A SC 383 it is being completely choked off by those manifolds; those are inadequate on a cam only setup...much less stroker+ power adder HP level.
TECH Fanatic
Joined: Aug 2008
Posts: 1,740
Likes: 2
From: Nebraska
You might as well go buy some longtube headers right now (and good gaskets) why bother troubleshooting an exhaust leak on POS stock manifolds. A blown LT1 needs to breathe...I wouldn't be suprised for it to pick up 40+ HP with the supercharger factored in. Then look into tuning, fuel system, intercooler/SC upgrades to make more reliable and add HP. A SC 383 it is being completely choked off by those manifolds; those are inadequate on a cam only setup...much less stroker+ power adder HP level.
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Thread Starter
Staging Lane
Joined: Oct 2014
Posts: 50
Likes: 0
From: Iowa
Thread Starter
Staging Lane
Joined: Oct 2014
Posts: 50
Likes: 0
From: Iowa
Thread Starter
Staging Lane
Joined: Oct 2014
Posts: 50
Likes: 0
From: Iowa
You are correct...those ARE headers, not manifolds upon closer inspection. You would be surprised at some of the things people do that don't make any sense at all around here....Like a Mustang/Mopar lover buying a LT1 Camaro of all things! Or this time some crazy dude started posting on a GM based forum claiming "Ford is better".
My Uncle was a body man, he's heavily into Mopar.
Are the current headers acceptable for this build? Or should I get better ones?
TECH Apprentice
Joined: Feb 2005
Posts: 384
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Those are indeed aftermarket headers -- not stock exhaust manifolds. They just happen to retain the factory emissions equipment (secondary air injection at least), which isn't surprising on a California-based car. They should be fine.
Can you see any model numbers on the Paxton head unit? 8~9psi on a 383 isn't shabby for an older Paxton. If I knew the pulley sizes and step-up ratio, we could calculate the impeller speed to see if you're overspinning it at all, but it's probably not a terrible idea to rebuild it with fresh bearings either way.
Despite not knowing all of the specifics, I'd run 91 (premium) at minimum, preferably higher if available. Don't want to run cheap fuel, being non-intercooled. Your compression, final ignition timing and IATs will have a large effect on when detonation hits.
I like the paint.
You mean Superfueler. The Superfueler came with the Paxtons and added the extra injectors up front. Versafueler is a peak-and-hold driver box for 8 low-z injectors on the rail (which would otherwise fry the PCM drivers due to excessive current).
Can you see any model numbers on the Paxton head unit? 8~9psi on a 383 isn't shabby for an older Paxton. If I knew the pulley sizes and step-up ratio, we could calculate the impeller speed to see if you're overspinning it at all, but it's probably not a terrible idea to rebuild it with fresh bearings either way.
Despite not knowing all of the specifics, I'd run 91 (premium) at minimum, preferably higher if available. Don't want to run cheap fuel, being non-intercooled. Your compression, final ignition timing and IATs will have a large effect on when detonation hits.
I like the paint.
You mean Superfueler. The Superfueler came with the Paxtons and added the extra injectors up front. Versafueler is a peak-and-hold driver box for 8 low-z injectors on the rail (which would otherwise fry the PCM drivers due to excessive current).
Thread Starter
Staging Lane
Joined: Oct 2014
Posts: 50
Likes: 0
From: Iowa
Those are indeed aftermarket headers -- not stock exhaust manifolds. They just happen to retain the factory emissions equipment (secondary air injection at least), which isn't surprising on a California-based car. They should be fine.
Can you see any model numbers on the Paxton head unit? 8~9psi on a 383 isn't shabby for an older Paxton. If I knew the pulley sizes and step-up ratio, we could calculate the impeller speed to see if you're overspinning it at all, but it's probably not a terrible idea to rebuild it with fresh bearings either way.
Despite not knowing all of the specifics, I'd run 91 (premium) at minimum, preferably higher if available. Don't want to run cheap fuel, being non-intercooled. Your compression, final ignition timing and IATs will have a large effect on when detonation hits.
I like the paint.
You mean Superfueler. The Superfueler came with the Paxtons and added the extra injectors up front. Versafueler is a peak-and-hold driver box for 8 low-z injectors on the rail (which would otherwise fry the PCM drivers due to excessive current).
Can you see any model numbers on the Paxton head unit? 8~9psi on a 383 isn't shabby for an older Paxton. If I knew the pulley sizes and step-up ratio, we could calculate the impeller speed to see if you're overspinning it at all, but it's probably not a terrible idea to rebuild it with fresh bearings either way.
Despite not knowing all of the specifics, I'd run 91 (premium) at minimum, preferably higher if available. Don't want to run cheap fuel, being non-intercooled. Your compression, final ignition timing and IATs will have a large effect on when detonation hits.
I like the paint.
You mean Superfueler. The Superfueler came with the Paxtons and added the extra injectors up front. Versafueler is a peak-and-hold driver box for 8 low-z injectors on the rail (which would otherwise fry the PCM drivers due to excessive current).
