So i hear a lot of different opinions on how much PSI you gain from various pulleys. Can any one for sure tell me the difference in PSI's in relation to the pulley diameter? What about rough hp/tq gains per pulley diameter?

 

Since many factors affect the output given by any pulley, since any pulley diameter cost roughly the same, I would suggest you to go to the smallest possible pulley supported by the stock PCM. The 2,8" will give you 5 PSI on top of the 12 PSI stock. It will also take you an adjustable tensionner arm. Bot parts are cheap.

http://www.zzperformance.com/cobalt_...0b90449f434982

http://www.zzperformance.com/cobalt_...ts1.php?id=447

Also, it is strongly suggested that you release some horsepower from the exhaust with that kind of boost. At least replace the rear muffler ...

 

thanks for the info!