Originally Posted by
Adam B
And finally, the belt tensioner. I do not run one. It does serve a purpose though, and that is to keep the belt stable and in theory allow for more consistent power to the front. You can also use it for tuning. The diffs can be rotated to change the belt tension. For example a tighter front belt might cause the car to pull out of a corner a little better, giving it close to a shaft driven car feel. You could tighten the belt with the tensioner, see how it feels, then rotate the diff to a proper position. I wouldn't use the tensioner all the time, but for a quick tuning change, why not?
I'm personally having issues with my front belt being a little long, which makes me run the eccentrics 3-4 notches back to get a tight front belt, which is lowering the diff. I'm going to be running a belt tensioner for the that issue, which should allow me to run my eccentrics as desired.
Conversely, my rear belt is too tight, and I have to run the eccentrics 1 notch from full back to get it loose enough, and it's still a little tight. Same as I had to do on my '11, I'm running a TOP racing rear belt, same tooth count but slightly longer, works very well.
IOW, I think a belt tensioner has it's place all the time, depending on your needs.