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cravnpup · 08-16-2000, 07:32 AM

I think what blown97GT is refering to is a pulley change. When you change the size of the pulley that turns the supercharger you change the speed of the supercharger. Decreasing the size of the pulley will increase boost above the normal rating. However, due to design of the supercharger, the roots-type blower (Ford Racing) phyically cannot spin as fast as the centrifugal blower (Vortech). The faster you spin a supercharger, the more heat you are creating, and so there is a limit to how fast each supercharger can be spun. So they only sell different pulley sizes based on the superchargers speed limitations. That is why you can only get 9lbs max out of the roots-type and can get 12lbs max out of the Vortech. For engines with the stock internal components, it is reccomended that you use a maximum of 6-8lbs of boost. With 6lbs you should see an 80-100 hp increase, with 8lbs you should see 100-120 hp over stock.

I hope this helps...

------------------
2000 GT Conv. 5speed
Triple Black
Current Mods: K&N
Future Mods: Too Many to list

[This message has been edited by cravnpup (edited 08-16-2000).]

08-16-2000, 07:32 AM	#5
cravnpup Registered Member Join Date: Aug 2000 Location: Torrington, CT, USA Posts: 145	I think what blown97GT is refering to is a pulley change. When you change the size of the pulley that turns the supercharger you change the speed of the supercharger. Decreasing the size of the pulley will increase boost above the normal rating. However, due to design of the supercharger, the roots-type blower (Ford Racing) phyically cannot spin as fast as the centrifugal blower (Vortech). The faster you spin a supercharger, the more heat you are creating, and so there is a limit to how fast each supercharger can be spun. So they only sell different pulley sizes based on the superchargers speed limitations. That is why you can only get 9lbs max out of the roots-type and can get 12lbs max out of the Vortech. For engines with the stock internal components, it is reccomended that you use a maximum of 6-8lbs of boost. With 6lbs you should see an 80-100 hp increase, with 8lbs you should see 100-120 hp over stock. I hope this helps... ------------------ 2000 GT Conv. 5speed Triple Black Current Mods: K&N Future Mods: Too Many to list [This message has been edited by cravnpup (edited 08-16-2000).]