boost problem

[turki95]

hi guys
i have 95 camaro lt1 engine. i have installed a 9:1 comp. pistons and h beem rods. and i installed P1SC procharger the problem is i dont get enough boost. i had 8 psi pulley and i dont see any boost then i have installed 15 psi
pulley i got only 4 psi!!! i dont know what to do i have tested the unit for leaks looks ok. the last test i have done was, i close the outlet of the unit with a plug that has a boost gage hooked in it so i got 15 psi max at high rpm,
is that normal should'nt i got very high boost since the air cant go no where?
please help me
regards ,,,,

i have 8 rib belt and i dont think i have any
slipage. i will remove the intake mainfold and check for leaks. but my q? before that is:
when i closes the head unit outlet and i have boost gauge hooked to it i got 15 psi was that normal,shouldn't i got much more than that?:weird:

[turki95]

nobody can answer this question?

[KS91Z28]

You won't build much boost just revving it up in park. The engine has to be under a load also. Give us some more info. How is your engine built? What diameter is your blower pulley. Your question is too generic.

[turki95]

hi...
the engine built with H-beam rods and all forged internals . the compression is about 8.5:1 . the blower is p1se with 3.4 inch which should give 15 psi at 5750 rpm for an lt1 engine . i drove the car while the pipe is totally colsed and the boost gauge is hooked to it to test the head unit and it is reading around 14 psi at high rpm ? i thought it should read around 30 psi which is the max boost the unit can handel .so is that mean the unit has a problem or is it normal ? when i connect the gauge to the manifolds i only see 4 psi while driving ...
i know that the intercooler drop some of the boost but not that much...
so what do you think guys ?
and excuse me for the spilling mistakes :(

best regards..

[KS91Z28]

You are seeing the correct amount of boost. The only way you would ever see 30 psi would be to put that blower on a little Honda motor or something. Boost is just a measure of restriction, and your engine is evidently efficient enough that you're only going to see around 14 psi from that P1SC.

[turki95]

but why i still see maximum 15 psi when the outlet of the head unit is totally closed?

[KS91Z28]

Are you seeing 15psi with the outlet totally closed at 62,000 impeller rpms?

[turki95]

actually , i don't know the impeller rpm but i see 15 psi when the outlet is closed...

[KS91Z28]

You're over-analyzing the situation. Just hook up the system, put on a boost gauge and go drive it.

[94BLOWNCOBRA]

You wont build much boost the way you are doing it! you just cant cap the discharge off, it wont draw the air into the blower well enough to make max boost!

Also, that rating on you blower pulley being "14#s", is a rating with a STOCK motor! So like said already, boost is a measure of back pressure, so if your motor breaths better than a stock motor than those boost #s are lowered.

Sounds to me like your P1SC igh be the wrong unit for your motor!

I could only make about 10#s on my car with a 17# pulley!