I finally took the car out for a spin. It made more boost than it ever has, pulled harder than it ever had, and even made big boost at part throttle instantly. I am very pleased with this belt so far, and no squeal or chirp at all.
The RPM belt must be tensioned different than a green belt or standard black belt. The RPM belts do not stretch hardly much at all (due to aramid core vs polyester core on green belt), so the tensioner must be at 50% or less compared to 85% tight tensioner position for a green belt. If installed at the same tensioner position as a green belt, nearly all the way tight, they will eventually snap when you let off and the tensioner slaps the stop. I actually moved my adjustable idler to a looser position than the pictures above, right at the 50% mark on the tensioner. I couldn’t get it any looser, so I ordered a slightly longer belt just in case this one is too tight and snaps. If you need want more explanation and videos comparing green belt vs rpm belt on a dyno pull, there is a great thread on a mustang forum that’s easy to find with a google search. I had no idea how much a green belt stretch’s at full boost, nearly the entire throw of the tensioner.
I have 20 miles on it so far, I’ll report back if I have any issues. So far, I would highly recommend this belt if you have slip or keep killing green belts. Best part, it’s black. Looks so much better on a white car.
The RPM belt must be tensioned different than a green belt or standard black belt. The RPM belts do not stretch hardly much at all (due to aramid core vs polyester core on green belt), so the tensioner must be at 50% or less compared to 85% tight tensioner position for a green belt. If installed at the same tensioner position as a green belt, nearly all the way tight, they will eventually snap when you let off and the tensioner slaps the stop. I actually moved my adjustable idler to a looser position than the pictures above, right at the 50% mark on the tensioner. I couldn’t get it any looser, so I ordered a slightly longer belt just in case this one is too tight and snaps. If you need want more explanation and videos comparing green belt vs rpm belt on a dyno pull, there is a great thread on a mustang forum that’s easy to find with a google search. I had no idea how much a green belt stretch’s at full boost, nearly the entire throw of the tensioner.
I have 20 miles on it so far, I’ll report back if I have any issues. So far, I would highly recommend this belt if you have slip or keep killing green belts. Best part, it’s black. Looks so much better on a white car.