Need input on pulleys.

[toxzzic1]

I have been doing my best to research this but just get confused. I have a powerdyne s/c making 5 lbs of boost. I am wanting to get it around 9lbs of boost. what pulley do I need? Please give some input.

 

[bentley429isBAC]

If I remember correctly I had to go down two sizes from the stock pulley to go from 6 to 10 psi. This was with the small crank pulley also and it was a BD-11a which is what you have correct?

 

[toxzzic1]

. The problem that I have is I am not sure what pulleys are on it now. It came on the car.

 

[bentley429isBAC]

So.....measure them?

 

[toxzzic1]

Exactly where do I measere from? Outside to outside? The powerdyne pulley bolts to the crank pulley. Do they make another pulley that will bolt to the crank pulley or do I change the s/c pulley?

 

[bentley429isBAC]

Exactly how much time did you spend researching? A vortech crank pulley will work if you want to swap that out instead for a larger one. When you measure the pulleys you measure where the belt rides.

 

[toxzzic1]

Is it better to use a crank pulley than a s/c pulley due to slippage issues when using a smaller pulley on the s/c? I just spoke to the guy that I bought the car from. He said that it had the pulleys on it that came from powerdyne. They bought the 6lb kit. What size crank pulley would make 9-10lbs?