[jnp]

Hoping you can help me!

I have a Ford Motorsport (Roots Type) supercharger on my 96 Mustang GT. The current pulley is 4" in diameter and gives 5 to 7 pounds of boost. I was wondering what size pulley I would need to buy and install to get 8 to 10 pounds of boost? Can you help me get the pulley I would need to do this and can I safety go to 10psi?

Thanks,
Jeremy

[GTRaptor]

I think you need a 66 mm (2.75") pulley.

[Crash!]

I would be thinking intercooling. 10-11 PSI Safely? Not exactly. Not even with a small heat exchanger like the Allen kit. TUNING will be required!

[GotTorque?]

It depends what size your crank pulley size is. To figure out theoretical boost for a positive displacement pump, you can use the equation:

Boost = ((((Crank Pulley/SC Pulley) * Blower Displacement)/(Engine Displacement/2))*14.7)-14.7

For example, I have a 2.2L blower, my crank pulley size is 4.75, and my sc pulley is 2.5"

With 4.85" crank and 3" blower = 1.62 pulley ratio

Boost = ((4.75/2.5)*2.2L/(5L/2)*14.7psi)-14.7psi = 8.11 psi (theoretical)

Hope this helps!!

-Cara