1QUICK Z

I had no idea it was bigger. I just went by his recommendation

1QUICK Z

I was just told that my 2015 has a little different tensioner pulley and this is the correct belt. Late 2016 and up can use the factory belt

CamOnlyJabroni

How much boost were you making with the 2.31 and now the 2.175?

1QUICK Z

I will find out this weekend. Finally swapping to the smaller pulley in the next few days

1QUICK Z

Just shy of one pound of boost difference between pulleys. I was running low to mid 12's before and now it's in the low 13's. Using the factory belt

CamOnlyJabroni

Thanks for the update sir. Sounds like I should gain a little over a pound then going from a 2.38 to a 2.175.

1QUICK Z

Sounds about right. Happy to help!

dar02081961

Correct Sir. That is a longer belt and will slip at high RPM.

dar02081961

The stock belt works fine until it gets a little older, then or at high rpm sometimes it slips.
The 080855 slipped on a 2015 with the 2.31.
I am almost positive it will slip on a 2.175 at high RPM or in the winter when boost levels are higher.

If you have doubts or question if a belt is slipping. Take a look at the griptech coating after a little mileage and some high rpm runs. Does it still look almost brand new? If not, the belt is slipping at high RPM and boost.
Another indicator is a barley noticeable slight black powder build up on the supercharger snout behind the pulley.

The pulley and tensioner part part numbers for 2015s are the same through at least 2018 as far as my references go.
The belt sizes below are roughly 6 to 8 mm smaller as the last 2 digits in the part number gets lower.

If you cross reference the below numbers on any belt reference chart you will find the below info to be correct.

OEM is equal to the K080852 which is equal to the gates https://www.gatespowerpro.com/Comerg...ctID=855298852

Shops are recommending the K08055 which is 8mm longer than the stock 80852. https://www.gatespowerpro.com/Comerg...ctID=855298855

The K08085250 I recommended is about 6mm shorter than the stock 80852. https://www.gatespowerpro.com/Comerg...ctID=855298850

Effective length in the specifications listed here on the gates site is the key.

Trust me I have been down this road, wasted a bunch of man hours to end up here.

Thank you for your informative post on the dyno numbers between the pulleys. Good reference info here. It should be a sticky.