Belt question before I buy

[arc00ta]

I searched and googled but couldn't find the right answer here. My setup is a 2.76 (I think) upper with 100mm aux idler. I've been going through Gates K080740 like they're candy. I keep returning it under the warranty but I feel like something is wrong. My tensioner is like 1/4" to the right of the "box" that shows where its supposed to be at, which to me says the belt is too loose. I'm getting a LOT of slip, enough to ruin the belt after about 200 miles. Also, watching my belt when the car is loaded on the dyno it barely moves the tensioner when going WOT, maybe 1/8th of an inch.

I'm looking at trying the K080733, because on the gates site the K080740 is listed as a 74 5/8" ID and the K080733 is listed as a 73 3/4" ID. Should I just try it and see if its better? Part of the problem is I'm not 100% sure if my upper is a 2.76 or not, its very ,very close to the blower snout though.

 

[Punisher03]

I have a 2.76 upper with a 100mm idler and run the stock length belt on it but i ordered a gatorback belt from summit racing due to chirping and squeaks with in a 1,000 miles of putting gates on. the gatorback has been on for 4k miles with no problem now,but i also am not to hard on my car either so not at wot alot!

 

[arc00ta]

Well I went ahead and got the shorter one, its quiet so far. The belt slip must have been worse than I thought because I got sideways on the on ramp way too easily.

 

[Alb Cobra]

If you tensioner is not flexing when you give it a little throttle action then your belt may be too tight, not allowing your tensioner to properly work, which will stretch your belt over time. At least that is the tad bit of info I got from reading metco website. Metco Motorsports

Maybe that is why you are going through belts quickly. I have a 2.8 upper and 100mm idler and it is so close I can't even squeeze the belt in between the pullies. I had to put the idler on last to get the belt on.

 

[arc00ta]

Maybe that is why you are going through belts quickly. I have a 2.8 upper and 100mm idler and it is so close I can't even squeeze the belt in between the pullies. I had to put the idler on last to get the belt on.

EDIT: After thinking about your post for a minute, I ran outside and checked my aux idler against some stock idlers I had pulled off last week and replaced. My aux idler is only a 90mm not a 100mm. That gives me an extra 1/2" of belt compared to cars running the 100mm idler. I realized this because I have about 1" of room between my idler and the snout pulley, and I remember seeing pics of how close they usually are.

 

[Alb Cobra]

Yeah it has been awhile since I have had a blower, if my memory serves me correctly when you crank down on the tensioner the indicator moves towards the driverside right? If so my indicator is to the right of dead center aswell but my tensioner flexes pretty good when opening the throttle body.