Originally Posted by idbeast

john, I'm trying to help out a guy with a Series One supercharged '95 Buick Park Avenue Ultra.
the following is a email he sent me, any suggestions??????????????????

Jim, you said you may have some friends that speak Series One supercharged '95 Buick Park Avenue Ultra - Pulley matters.

I removed the 2.85 " OEM pulley, and installed a 2.55" OEM pulley of from a '93 Park Avenue. I can feel the difference when I put a fresh dose of Mobil One in it, or when I service the K&N air cleaner ... but I could not detect any change in performance with the pulley change. I did the ten minute battery disconnect thing, and tought it everything I know.

Shut down, the actuating rod on the Boost Modulator Valve is fully extended, start the motor and rev the engine and the rod retracts about half way seeminly in direct proportion to the amount of throttle you give it. This is hard to do while your driving. You suggested putting a gauge on it to see whats happening - where would I put the gauge ?

The first attached picture is the car - duh - the second picture is of the Boost Modulator Valve and shows boost bypass lines coming out of the intake plenum with one line dropping downward and going to a rectangular filter block, out of the filter with a sharp ninety degree bend of formed hose (no longer available from my dealership) and directly into the backside of the Boost Modulator Valve (waste gate).

The third picture is from above and over the left fender showing the a bevy of vacume lines ... one of which feeds the A/C system etc.

I 've missed something here - Jim - and I don't know what it is. I haven't realized any changes in performance with the pulley reduction. Got any ideas ?

Originally Posted by F14CRAZY

BTW, if you need a BCA, call Magnuson for one. They're much, much cheaper ($40) than GM ($300 something)