When i first got my car back i was showing a steady 8lbs of boost... Then sometimes it would show 8lbs and others it would only show 6lbs... Now the most i get is 6lbs of boost... Speed inc told me not to tighten the belt anymore... Can i hurt anything by tightening it to tight? My car is tuned for 8lbs and i want the full boost.... Also how much VAC do you guys see when your car idles??? Thanks

 

If the belt is new, then it stretched which is normal for a new belt. Look under the car at the brackets and see if you have black dust on the brackets, if you do, then tighten it up more, should be tight enough for the belt to hum, when plucked from the side. If it isn't new and has plenty of miles on it, try to tighten it down and if that doesn't help get a new one and coat it with belt dressing before it goes back on the car.
This is what I had to go through when running the 6 rib.

And yes you might be able to hurt the s/c internals if you tighten the belt waaaay tight.

 

I see about 18-20 Vac at idle. I have the same boost problems too when changing belts. Anyone have a problem with the Gates Belts? They always jump off of my pulleys! The Gatorback belts are the only ones that I can get to work! I have tried Gates and some other cheap serpentine belt from Autozone and niether of them work. I buy a Gatorback and put it on. It works fine! Go figure!

 

Well i changed the blower oil a couple of days ago and there was a little flex in the belt but not alot...I didn't see any belt dust... Also it seems like it takes longer for the boost to get going and doesn't act as quick.... The belt has about 600 miles on it... Well i will try tightening it and if that doesn't work i guess i'll try the gator belt...

 

Well now sometimes all i see is 3lbs of boost... I tried tightening the belt a little more but don't want to over tighten... I thought about trying the gator belt... Where did you get your gator belt from??? Also with long tubes w/ORP and flowmaster catback what size pulley should i run??? I forgot what size they sent me....

 

I buy the Goodyear Gator back belts at a local Parts store. They are about $15.00 a piece!

 

Do you know what size belt I need for my mods???