ranedoss27

iTrader: (4)

From reading various threads on here it seems I need to be around 50000 rpm to make around 8 psi on my set up and right now I'm getting 2 psi at 6000rpm on the the motor. I feel like I'm losing some psi due to my exhaust, cam, and FMIC. I currently have a 6" crank pulley and a 4.25" blower pulley. Im thinking about swapping to a smaller blower pulley to get more boost and want to make sure I'm on the right track and make sure it's not something wrong with my set up

MadIceV8

iTrader: (12)

That is a small crank pulley. I assume you are running a 6-rib setup then? I believe procharger provided a 3.7" to achieve about 5psi and a 3.4" to get 7psi.

Bob@BruteSpeed

iTrader: (16)

How much boost the blower can produce depends on many variables.
* Cubic inch. The larger the engine the less boost it will make with a supercharger.
* Headers and exhaust. A better flowing system will produce less boost, requires a smaller pulley to regain the loss in boost. Ultimately though, more power will be gained.
* Camshaft and heads. A camshaft with some overlap will leak out some boost through the valves. Better flowing heads react a lot like a better flowing exhaust system.
* Altitude. Elevation plays a big part in how much boost is produced. Those people living in the higher elevations have to spin the blower harder to see boost.
* Condition of engine. An engine with real good sealing rings will ultimately produce more boost than one with worn rings.
* Rpm. An engine that is spun up higher in the rpm range will normally produce more boost.

If you have a basically stock F Body with headers and exhaust, a D-1SC 6 rib kit with the 6.0" crank pulley and a 4.0 blower pulley will get you around 7 psi, if you're around 500 to 1000 ft in elevation. Whatever aftermarket cam you have is going to lower the boost.
http://shop.brutespeed.com/ATI-DPxxx...-ATI-DPxxx.htm
A 3.60 pulley should put you close to 8 psi. Bob