Pulley Combos for an S-port

Dahoopd

Registered User
I have a 94/95 blower with a 89-93 pulley on it. With an S-port, what would be the recommended pulley combination to run. I have underdrives and the heads and cam are stock?


10% crank, Stock JS, 89-93 pulley
or
5%JS, 89-93 pulley
or
10%JS, 89-93 pulley


(Excluding exhaust worries) Thanks for the suggestions
 
Are you running an MP inlet plenum? If so, 5% will net you 17psi which is more than plenty.

Are you running a stock intercooler? Depending on what intercooler you have will determine what level of boost leads to more or less detonation. On a stock intercooler, I wouldn't recommend running anything more than 15psi.

Considering pulley combinations, a late model blower with an early model pulley is 3% OD, thus, switching to a 5% blower pulley is an actual 8% OD. This would be the same as running a 5% JS and an 89-93 blower pulley (which is what I would suggest.) The larger blower pulley that you can run, the less prone you are to belt slippage.

Another good way to do it would be find a late model blower pulley, use the stock JS, and use an MP 10% crank pulley.
 
Are you running an MP inlet plenum? If so, 5% will net you 17psi which is more than plenty.

Are you running a stock intercooler? Depending on what intercooler you have will determine what level of boost leads to more or less detonation. On a stock intercooler, I wouldn't recommend running anything more than 15psi.

Considering pulley combinations, a late model blower with an early model pulley is 3% OD, thus, switching to a 5% blower pulley is an actual 8% OD. This would be the same as running a 5% JS and an 89-93 blower pulley (which is what I would suggest.) The larger blower pulley that you can run, the less prone you are to belt slippage.

Another good way to do it would be find a late model blower pulley, use the stock JS, and use an MP 10% crank pulley.

See, I should have asked before jumping. Its an aftermarket FMIC. I do still have the stock JS pulley but gave away the SC pulley. I am in the process of buying a JS pulley and wanted to make sure I ask first. Thanks for the help, I appreciate the imput. I will just go with the 5%JS and the 89-93 now.
 
I would just try using the pulley you have now, because with stock heads and cam I think your already going to be over 14 pounds of boost with an S port at 3% OD. If you need more boost, you could always add the 5% JS pulley later.

David
 
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