cheddaboy

I have recently swapped my 3.8" pulley for a 3.6" and I am reading lower boost. My only conclusion is that the belt is slipping. I have a 6.75" pulley on the crank and made 17.5-18 psi @8000 with a 3.8" pulley. With the 3.6" pulley I am logging 13.8 -15 psi. I now question my belt tightness. Is there a more accurate way to measure the tightness of the belt other than the twist test? I've read that you can use a torque wrench on the tensioner and that should give you an idea of how much its pushing on the belt.

Ideas?

dshea

Make sure the nut that secures the tensioner is torqued to spec. I use this adapter with an adjustable wrench to get around the clearance issue: https://www.amazon.com/Motion-Pro-08...wrench+adapter

Once you know you've been tightening the nut properly, you can eliminate that as a variable. Then you can experiment with the belt tension until you get what you expect.

E4RTH WORM JIM

Tighten it until is stops slipping! That's the correct amount of tension.

Loads of people use that pulley size and smaller without slippage so you won't do any damage if you keep adjusting it until it stops.