: cam torque



96-deville-man
03-25-06, 06:21 PM
Ive got my buddy`s vortec superchager im trying to use as a mock up. For my superchager setup. we were trying to find the best way to drive it. we came up with driveing it off the cam that drives the waterpump. I need to know what kind of stress the cam will handle? and what the ratio is for what rpm the cam spins relative to the engine rpm? I figure if this goes together like we are hopeing i may beable to do this for about $2000 maybe less including a PCS X-F-C. Im looking for about 5-6psi wich should get about 400 to 500hp. maybe alittle more with a port and polish.

eldorado1
03-25-06, 07:09 PM
Not a good idea for 2 reasons -

1) The cam is driven at 1/2 the engine rpm. The supercharger needs to be run at twice the engine rpm (roughly). This means you'll have to have a large pulley to make up the difference. The smallest supercharger pulley is maybe about 2", so instead of a 4" drive pulley, you would need an 8" drive pulley.

2) It requires maybe 30-40hp to drive the supercharger. At 3000rpm (roughly the maximum cam rotation at redline), that means it's going to be drawing 70 ft-lb of torque through the cam. Not only through the cam, but through the cam chains. This will put a lot of added strain on the tensioners chain, guides, etc. It may not last 100 miles.

Either you need to mount it in front, or you need to build a driveshaft for it to cross the engine.

96-deville-man
03-25-06, 07:12 PM
Not a good idea for 2 reasons -

1) The cam is driven at 1/2 the engine rpm. The supercharger needs to be run at twice the engine rpm (roughly). This means you'll have to have a large pulley to make up the difference. The smallest supercharger pulley is maybe about 2", so instead of a 4" drive pulley, you would need an 8" drive pulley.

2) It requires maybe 30-40hp to drive the supercharger. At 3000rpm (roughly the maximum cam rotation at redline), that means it's going to be drawing 70 ft-lb of torque through the cam. Not only through the cam, but through the cam chains. This will put a lot of added strain on the tensioners chain, guides, etc. It may not last 100 miles.

Either you need to mount it in front, or you need to build a driveshaft for it to cross the engine.

the drive shaft was my first thought. thanks for clearing all that up. I knew the supercharger needs to spin that fast. thanks.

eldorado1
03-25-06, 07:19 PM
That's what these guys did:

http://www.angelfire.com/stars/mycaddy/northstarsuperchargerphotos.htm

96-deville-man
03-25-06, 07:36 PM
That's what these guys did:

http://www.angelfire.com/stars/mycaddy/northstarsuperchargerphotos.htm

yep im gonna do somthing relative to that. thats what gave me the idea. i figure i can get about with a unit from ebay for about $200. this guy who im using his unit for a mock up is probably gonna get me all the stuff that is nesary to do this. he will also heko me get the piggy back hooked up.

danbuc
03-26-06, 02:22 AM
That's the system XMS Racing was developing a few years back that never really produced any results. It looked to be a relatively sound design though.