ok so before i had the cxracing heat exchanger on there by itself (i took off the stock one completely) and i was just running the stock h/e on the 2.7 pulley, i would boost 15lbs and at around 6 grand boost would drop to as low at 7 psi in 2nd and 3rd gear up to 7000rpms. So i put the cxracing h/e on and not i hit 17.5 lbs of boost randomly but usually around 16psi and i start to drop to around 12.5 psi at 7000 rpms. My question is what could this problem be? My diagnose:
1. Could the I.C. pump be broken and not circulating the coolant?
2. Could i just be running too hot temps causing boost to decline?
3. Could my supercharger gasket be leaking? (i have used the same gasket and taken off the supercharger 4 times still with the same gasket).

let me know. thanks.

p.s. The car definitely feels more cosistent and powerful now that the cxracing h/e is on. i can def. tell it made a difference.

 

This is a stupid question but do you have a stage 2 belt and/or an adjustable tensioner?

If belt slip isn't your problem my next best guess would be boost leak but normally I think you leak boost constantly, not past a certain RPM.

 

yeah i have a stage 2 belt. i am almost 100% sure its not belt slip. i think im gonna go order another gasket tomorrow and install it. maybe there is a tiny leak. im getting meth soon too so that should clear things up a bit i hope.

 

bump. c'mon guys anything?

 

Where can you get one of those s/c gaskets? I think mine may have blew.... What altitude are you at? That really really makes a difference... i get around 17psi with a 2.8, and ive read some people get 14.5 and 15 in some areas with the same pulley...

Mind you im at sea level in florida...

 

just go to a dealership. i live in reston VA so i dunno the altitude. i know its not too high tho.

 

your just under 300 feet, so i dont think it would be that much of a difference...

Did you have your car custom tuned? There could possibly be a boost limiter in place...

 

yes its custom tuned but there is no boost limit. plus i dont think it would limit it on a linear graph as you go into higher rpms. thats beside the point tho bc there is no limiter.

 

could be the ecu limiting boost based on IAT2 temps. meth injection is a MUST with a 2.7 pulley
probly isnt your s/c gasket. that would be causing your oil dipstick to blow out, among other things (fucked up idle)
Stage 2 belt with a 2.7" pulley might slip. usually anything less than a 2.8" requires a different tensioner.

 

well my idle does bounce occasionally. i went to the dealership today and they quoted me 67$ for a s/c gasket. is that right? i thought i saw somewhere that they were less than $40.

 

ya thats about right. dealerships will rape you on parts

 

yeah im really close to being sure that its the gasket b/c my car will hit 17.5 psi whenever it feels like it (when im at WOT) and the other times it will only hit 15 psi. my throttle also drops really low occasionally too.