Supercharger belt slippage???and more

XxSlowpokexX

Registered User
Hmm lets see..94 SC...Car has headers, full exhaust, raised top, bigger intercooler, smaller charger pulley..Car pins boost at 15 then around 5,000 rpm it goes down to 10..And I mean you see the needle just drop. I'm thinking belt slippage..Also are the steel tensioner pullys worth it?..Thanks
 
Do you see alot of "black dust" on the S/C snout?

If you do, then that could mean that there is significant slippage.

Are you running a 5% or 10% pulley?

There are a couple of things you can do about slippage, one, maybe your belt is due for replacement anyway. But you might want to go with the goodyear gatorback belts. I've heard good things about them and I know that they are very quiet.

Also, I have the steel tensioner pullies. They do quiet down the belt noise significantly.

The steel tensioner pulley for the superchager belt is 1/8" larger diameter, which means it is going to put a slight amount more tension on the belt. It's tougher to get the belt on the car though, but I did it with my stock pully. You might have an easier time with the smaller pulley.

Consider a slightly smaller belt too.

A loss of 5psi, at a certain RPM does sound like belt slippage, but it could also be something else.
 
Well it looses the Boost and it stays that way..close to 5000 rpm's...Belt does look like it could use changing...And honestly I dont know what size pulley it is..Looks smaller then the one on any of my pre 94 SC's..Came with car when I got it..Think I might go with a new belt and tensioner set..Well see what happens:O)
 
I'd whip out a tape measure....

And I'd measure the OD of that pulley and compare it to my other car (if I had another SC).

At any rate, 94-95SC pullies are supposed to be slightly larger since they spin the blower 3% slower than the previous years did.

So if your pully on your 94 is smaller than on your other SC, yes, you have an overdrive on it.

I put a good year gatorback belt on my sister's boyfriend's Buick Regal's V-6 engine (now there is a refined engine). And it was much quieter than the tattered old belt.
 
I just installed a 10% OD pulley on my 90 SC, I'm using the stock belt (I have the "short" belt on order) and I AM experiencing slippage. I can actually hear the belt slip. It makes a screaching sound. IMO you need to find out which pulley is on the car, and which belt is on it. If you can still read the belt number, the stock will have 392 for the last three digits if it's a Gates, or a Dayco. The shorter belt would say 390 (Gates pn # K080390) for the last 3. When mine slips, it only happens under hard acceleration when the boost gets up around the 14-15 psi mark, and to be honest, I've never watched the boost gauge once I hear it start to slip....I just back off it. Can you hear any slipping noise at all? I'm gonna see how mine does with the new belt (if it ever comes in) but I might throw a new steel pulley on the tensioner anyway. Those plastic jobs are junk!
-Jeff
 
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