62.6" correct belt for 9.1" lower and 2.55" upper?

[FFBOS]

I have an 8.6" with 2.55" now running a 67" belt.

I believe 62.6" is the correct length with running a 76mm idler as the top idler?

With the 9.1" lower

Correct?

[Mike_11CTSV]

That doesn't sound right. Did you get that from their pulley instructions chart? The chart is all screwed up. If you're running a 67" and the pulley is .5" larger, thats 67.5".

[Tim@Lingenfelter]

Here is the latest chart for different Cadillac CTS-V & Camaro ZL1 applications. We will have an idler relocation bracket that will be available for the 18% & 22.5% versions next week.

[Mike_11CTSV]

You don't need to relocate the idler, you just need to use a smaller lower pulley with the bigger balancer pulleys. You're making it more complicated then it is. A simple 50mm lower idler is fine up to a 9.55. Then you need to relocate. Its also recommended to run a 100mm upper idler with any upper supercharger pulley swap to maximize belt wrap.

[FFBOS]

Yea I had to use the 50mm lower idler. There was 1/10,000 inch clearance between the 9.17" and the stock lower idler. My installer didn't feel comfortable using it.

I used a 67" belt and it seems to fit fine. My tensioner mark on the tensioner is all the way to the left.