Just looking for some advice. I bought a Greddy profec B spec II boost controler back when I was looking to put a turbo set up on my car. Now I have changed plans and am going with a ATI Procharger. Will I still be able to use the boost controler or will it be mostly useless to me now?

Allen

 

for sc's to make or take away boost u have to do pully swaps, thats why I went turbo :P lol

Jay

 

What I don't understand is to control the amount of boost you are making on a turbo setup you have to bleed boost off somewhere. Can't you do the same thing with a s/c?

 

You don't bleed boost off, you bypass any extra exhaust around the turbine once the turbo has reached the needed speed to produce the desired level of boost. To do the equivalent you would need a system that stops the blower pulley from going any faster at a set boost level even though the motor keeps reving higher.... so an apples to apples doesn't really work.

I have seen some strange setups where it was basically a wastegate on the chargepipe of a supercharger.... Don't know how well it works.

Example - You pulley it for 12psi - but only want to run 6 - Its supposed to get there and hold 6 psi much better across the board, since the pulleys are designed for higher boost. Again I have no personal experience with this.

 

Well on a turbo you are using exhaust pressure to creat boost, the wastegate opens at the desidered amount of boost/pressure and doesnt allow the turbo to spin faster.

I mean im sure it could be done on a centrifugal type supercharger on the cold side somehow mbut i have never seen it done and i dont know how it would even control it. it would act like a huge boost leak then not get power and run rich.

Jay

 

^^ Good point it would have to be speed density or the maf would have to be between the gate and TB - but that might cause issues too.

 

Well thanks for the advice. I guess I'll sell the boost controler and pulley the s/c to about 25 lbs. of boost and run it all out all the time.

 

Hope you've got a big procharger.

 

I had a 1998 Grand prix daytona edition GTP back in the day that had a 12psi pulley on the S/C. The wastegate on that S/c was internal (after MAF and behind throttle body but between the S/C and intake manifold). The wastegate was adjusted by a vacuum actuator and I hooked up a manual boost controller (turn style valve) to it and could regulate the boost... but I could only lower it from what the maximum the S/C would put out with that pulley. I later pulled the s/c and converted it to a turbo system but anyways......

That type of boost controller is intended to build up exhaust pressure and spin the turbo faster to build boost. with a S/C your max boost is limited by your pulley or S/C. the only thing you can do is regulate the boost pressure to the wategate to get it to open and lower your boost. You will not be able to increase your boost over what pulley or S/C combo you have.

If you want to adjust your wastegate on the fly and lower boost you are better off with a manual valve type boost controler on a S/C since your S/C responds somewhat linear to rpm as opposed to a turbo which is more of a load responce you dont need to play with start boost, gain and all the other settings..

FWIW I have a greddy profec spec II on my turbo car.

 

If you decide to sell it let me know, I might be interested...