so yea the title pretty much describes it....im just wondering what is causing this....my mods are listed below
and for 20psi it just dosent seem to pull like it should

so any helpful information would b greatly appreciated
thanks

 

sounds like clogged cat

 

the car has a catless dp

 

there is a restriction elsewhere in the system.

 

either wut blown has said, or you are running alot of retarded timing. more then likely a restriction.

wut altitude are you at and wut size pully 77.9mm 2.8, 2.7 ect. i know is gm stage kit, but theres a few pulleys for it

 

i mean there is a slp muffler on the system....but it might b clogged...any other thougths or info about fixing it

 

its the factory gm pully and tune...

 

seafoam the car and get a header.

 

the car has a badmab header on it that i forgot to mention...and ill prolly try that...

 

might wanna have your tune checked then maybe. I'm running the GM Stage 2 on the 3.0" = 77.9mm pulley and i am hitting just a little over rated 15.5psi and thats only on cold days at redline in the higher gears, but i'm also stock header, downpipe, and catback. Just have a different muffler.

 

take your catback off from the down pipe, itll be loud, but this will tell you if you have a issue with restrictions. run the car get into boost and see

 

is the car slow when you floor it

 

ill try taking off the cat bak...and slowline it doest seem as fast as it did when i floor it

 

thanks for all the info guys....ill try the stuff and see if that works
any other bits of info r greatly appreciated too

 

Im gonna say busted gauge or smthing along thoes lines, im on a 2.85 and will be lucky to see 16psi on a cold day.

 

the car was reading it on the stock boost gause and on the new interceptor i just put in...so im pretty sure that isnt it...but thanks for the info

 

hows the car run? could be a bad map sensor.

 

i havent really beat on it too bad from what i have it runs and sounds fine....its just the boost issue...i just installed my interceptor and im monitoring all the stuff..is ther something i should look at more closly?

 

restriction restriction

 

I just fail to see where that much resection could be in a exhaust setup you can roll marbles threw,Unless something is crushed or the mufflers exploded on the inside.
The only other restriction i could think of would be inside the intake manifold if something were to clog the cores ,but the map is mounted on the cold side of the IC (after the cores) ...but who knows ...keep us updated

If the car was recently flashed it could be a ecm firmware issure, the boost gauge receives its signal right form the ecm so that would explain why both the interceptor and stock gauge are reading the same.

 

exaust valves are stuck closed, but you would hear it, when you were catted the peice of catt got stuck in the muffler. Your cars iat2s are high because you havea bad ic pump, with hotter air itll boost more, as like colder will umm its hard to determine, check your iat2s when at wot and ect.

 

I'm pretty sure hot air is less dense.
And the only way valve would get stuck shut would be catastrophic failure in the valvetrain.
However it is possible for valves to hang open at high rpm or due to fatigued or broken valve springs.

 

by god i hope your not talking to me like i am a idiot. First off, if your ic pump works take it off do a few runs get your iat2s up there and see what im talking about. colder air is dense, but with warmer it can pact more air in . About the valve train i am givingyou options you ask us help, and trust me, im one of the people on this forum that can give it to you.dont take this as i am pissed but i cant stand when my words are questioned.

 

I'm with you on everything except your theory on air density heh.

Colder air is denser meaning more air molecules fit into a smaller volume of space.

 

you are correct here sir, colder air is more dens so therefor more air can be packed in. Now do this for me if you dont belive.......... if a car is tuned for the boost to be limited it wont happen, but if it isnt then one thing you can do is unhook it let the iat2 get hotter then 200 which is truly bad and your boost will raise no joke, im not saying hotter air is denser but its as if it pack more air in, possibly because of timing retard from hot iat2s unsure id have too check but t does happen