Hi, yes you should change it but you also use a shorter one. If you use stock length belt then 2 problems arise...Firstly as the belt stretchs the tensioner assembly will hit the stop before it should. Secondly under fast engine acceleration the elastic nature of the belt means again it will hit the stop. Both situations will give slip. The first all the time once its on the stop, the second momentarily.
Even
JCW uses a shorter belt and thats with a 11% pulley!
A stock belt will get you by but its far from ideal.....
We include & fit a shorter belt with all GTT conversions.
Best Regards Roland GTT
