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View Full Version : Is there a way?



tim
05-31-2004, 11:20 AM
My car is now running a 5% od. pulley makes 11.5 lbs. of boost. It wont handle a 10% pulley to much. I dont know if anybody has run into this problem. I wonder If there would be a market for say a 7.5 % pulley, I sure would buy one. Seems to me that 5% to 10% is quite a jump. Aluminum would be nice.

Mike8675309
05-31-2004, 02:48 PM
There isn't much point. You can gain performance through doing so many other things that just bolting on a pulley.

If you follow the adventures of the guys messing with a Whipple charger on their SC, you'll see that one of the main issues is air flow through the engine and heat generated by compressing the air.

You need to resolve those other issues before gaining much performance from anything above a 5% pulley.

Keep in mind the sizes are based on the early model SC pullies. The 94/95 cars had a slightly larger pulley, so a 5% on a 94 blower isn't quite 5% overdriven.

ThunderDave
05-31-2004, 06:08 PM
That seems kinda low to me. I put a 5% od pulley on mine and I have close to 15 at max. rpms. I feel like I had a leak in an intercooler line or something because before I took it apart to do the head gaskets, it was only making about 12.

After getting it all back together, the boost was up. I don't have many mods either to account forthe rise in boost, so maybe you might want to check for leaks before doing anything else. Just a thought.

David

tim
05-31-2004, 08:48 PM
My car has a lot of mods that make it flow really free. Headers, dual exhaust, ported everything, 75 mm. throttle body and 76 mm. mass air. That is the reason it only makes 11.5 lbs. of boost. I really wanted to be at 15 lbs. of boost but with my compression the engine wont take it. Can I change another to make the blower turn just a tad faster? Is that aluminun jack shajtshaft pulley really worth 12 hp. to the rear wheels. I dont mind spending the money if it really works. Thanks Tim

Mike8675309
06-01-2004, 07:19 PM
The aluminum Jackshaft has been dyno proven for at least 7hp. The stock Jackshaft is heavy.

You can add a 10% SC pulley plus a 10% jackshaft pulley to get a total of 20% overdrive on the blower. You have to watch out for max sc rpm though. And those that have tried it have struggled with belt slippage. Thus the 10 rib setup from ESM.