Does anyone know of an upgraded SC belt tensioner? I'm running a 4.2 lower pulley and 6% upper pulley with a brand new gates HD belt and it likes to slip badly at 5000 rpm. The belt is 1345mm long and fits comfortably in the middle of the tensioners range.

I can get a new tensioner, but I don't really think it will solve the problem. I'm hoping there's an upgrade or perhaps an option that locks in place rather than uses spring tension. Does anyone know if the 4.2 cars had a superior tensioner?

 

I haven't seen anything about an upgraded tensioner; maybe the belt is a bit too long? When I did my larger lower pulley the belt size was specified by the builder, so I didn't have to hunt. The belt should just barely fit over the SC pulley with the tensioner fully opened to the stop.

 

I think my belt may be too long at 1345mm. I ordered one that's 1306 and am going to see how that fits. I do think it's possible the tensioner may be too close to the end of it's travel. I'll report back with findings.