TommyF

Hi, i`m trying to help a friend to solve a problem with his supercharged LS1 `57 Chevy.

It will not get higher boost than 2-3 psi.
The engine is a LS1 from a 2002 Pontiac Firebird. The supercharger is from Procharger and a intercooler is also installed.
The only thing that`s not original on the engine is the Sanderson headers.

Somebody who can help us to solve the problem?
He want to get a boost on 6-7 psi.

conan

iTrader: (5)

Is that a blow off valve he's useing? Check to make sure its closing all the way. Also have you gone over all the hose clamps with a socket wrench to see if any fittings are leaking? Also has the car been driven, your only seeing 2-3 psi when the engine has a load on it.

ChevyChad

iTrader: (50)

What size pullies are on the crank and the head unit? 6 rib or 8 rib belt? P1SC or D1SC?

Also, not that this is the immediate problem, but that filter is tiny. I'd ditch it in favor of a much bigger one.

Brent@LPE

That is the older style blow off check it over to make sure it is not stuck,make sure the diaphragm in the pull off is good ( suck on the vacuum line ) It will not show much boost free revving it as said above. You will not see full boost until 6k. I would get it on a dyno.

Brent

TommyF

Yes, the car have been driven and the guage show 3 psi on full throttle.
We can check the hove clamps one more time! How can we check that the blow off valve dont open when it not shall?


I dont have the size on the crank, but we have called Procharger and we got a new crank from them(the crank ProCharger think was the best for the this supercharger), but it was the same we already got! So that was not the problem. (P-1SC)

The filter is repleaced with a bigger one already.

Thanks for tips and tricks!

conan

iTrader: (5)

If the the check valve is vacume operated, like the newer bypass valves, start the engine and pull the vacume hose off and put your hand over the out let if you feel air its not closing all the way. Plug the vac line in and it should open up and blow alot of air. When you pull the vac line off you should hear the blower cavitate. Also you can spray soapy water on the intercooler if the by pass is closing all the way and see it the cooler is blowing bubles.

BadgeZ28

iTrader: (28)

Does procharger make forward and reverse rotation drives? Or is it a straight cut gear that can go either way?

TommyF

I suck on the vacuum line, and it opened the valve.
When the engine is off the valve is locked, but when the engine is running the valve is opening (and stays open to we stop the engine). Is that right? I though it would open when it was to high pressure?

The valve is vacume operated but is it correct where we get the vacume?

I got some more pictures for you!


As i said, this valve is locked when the engine is off, and open when it is running.


Here we got the vacum to the valve (on the picture over).



And another thing...


This hos is going from the channel where the air goes in (with the airfilter in front of), but where should it go? It suck in air so we just gave the hos a airfilter on the other side of it.

I hope you understand my bad english. It`s hard to explain when you are not so good in english

EPP

iTrader: (22)

The bypass valve is designed to release all the compressed air until the valve sees near zero vacuum, which would be close to wide open throttle. When looking at the valve in the closed position there should be a slight air gap as the blade does not fully seal it off. If the valves gap is too large it won't build the boost you're looking for, as it will bleed it off. To see if the bypass valve is the culprit, you can temporarily remove it from the system to where the engine is always getting the boost, and make a run or two to see if you see more boost. You don't want to leave the bypass valve out of the system for good, as when the throttle slams shut all of this boost has no where to go, but to try to slow the supercharger down.

If the bypass valve is good, then you might try taking your intercooler plumbing loose at the blower and the throttle body, cap both ends but install a schrader valve in one in so you can hook an air line up to it to pressurize it.

Last but the first thing to check for, belt slippage. If you see black dust on the blower your belt is slipping. The blower belt needs to be much tighter than a normal drive belt. A new belt stretches after a half an hour on run time or so and needs to be retightened.

With a ProCharger system, the crank pulley will be a fixed size and the pulley on the head unit is the one that you change down in size to make more boost. There should be a number stamped on the side of it to tell you what size it is. Bob