My 03 MCS 135000miles has shredded two belts in 2 months . Both times was during high rpm shifting . I currently have a 15% sc pulley and the ATA 2% crank pulley . Is this an indication of a worn tensioner or something else like incorrect belt size . Also I could use a blet size recommendation as its very confusing . All I can find are belts for stock, 15% sc . and 17% sc + 2% crank . Cant seem to find 15% sc + 2% crank . Thanks

 

I know this is a late reply but 15% SC pulley +2% crank pulley is going to be a stock belt. Because the 2% is oversized by 2% so makes up for the reduction in size of the SC pulley.