belt screech?
 

So I have subs in my s197 and they roasted the alternator. I bought a bigger one off am (can't remember the amps) and installed it. Now when I'm wide open and it shifts it sounds like a belt slips or screeches for a split second. Any ideas on what that could be or how to fix it?

Does it do it while you're pissing off everyone within a mile radius (i.e, does it happen only with the amps crankin') or all the time? If it's the latter, then I'd say the belt tension isn't correct. Matter of fact, it probably isn't correct either way...

Ya I can only hear it when I'm not bumpin haha. How do you change belt tension?

You can't adjust belt tension. Replace the belt, it's probably stretched.

I wasn't sure about that. Thanks, moosestang.

No problem. If he had a positive displacement supercharger, then he could adjust it. I believe they all have some sort of sliding idler pulley.

he could replace one of his stock idler pulleys with a larger one, but this might give you too much tensioner. I have a 90mm in place of my 70mm on my tensioner and a 100mm in place of one of the 90mm's.

Also, could go with the "frankentensioner" mod which will double the tension, also some of the slipage may be coming from tensioner arm flex in which case an aftermarket tensioner like the thump racing one could help out... but start with a new belt, they are cheap.

Sounds good, I'll try throwing a new belt on and see what happens!

My screeches after going through a car wash or while driving in the rain. Lol

FWIW mine also does this on hard shifts using the PA Performance Alternator.