Hello Everyone:

I just went into the local gas station for my state inspection. The guy noticed that I needed a new serpentine belt. Is the stock belt OK or are there better ones ou there like the JCW belt? BTW I have a 15% pulley installed.

Thank you!

 

Napa 060535 is the belt you want for a 15% s/c pulley and 0% crank pulley. Dyno proven not to slip. Since the belt drives the accessories and the supercharger [which sucks up about 50 HP alone!], it's a good idea to plan on replacing it about every 20k miles.

 

don't use the stock belt, even though the car will run chances are when you get to high rpm (5,500 n' up) the belt may be slipping even though you may not feel it

 

also just to make sure that you have the correct belt check the tensioner after installed, you'll want to see at least one hole showing on it more or less

 

Thanks everyone for their input. I did a little more research and found something on Detroit Tuned's website about a tensioner stop http://www.detroittuned.com/products...20070112214410. Is this something good to have or really not necessary?

 

Probably not needed with a 15% pulley...but it sure is cheap insurance for your crank pulley and tensioner

 

Would've saved LOTS of €€€ for me if I'd've known. I'm so sure of trouble that I would've installed the DT strap at the same time as the 15% Alta v2 pulley. Hope you have better luck than me.

Cheers!!

 

i just got the m7 2% crank pulley. any recomendations on belts? i have the 15% also. (not trying to hyjack the thread!)

thanks

 

You could use a 539 belt as well.

 

You could, but there's a good chance it will slip to one degree or another.

 

Same question here....I shredded my belt @ Watkins Glen on Monday. HELLO limp mode! Happened going into the toe (turn 7) on my out lap in the 3rd session. Lost the rest of the day since it was Labor Day. I'll add this to the list of spares to bring. After Napa delivered a new one (#25/060547), stock size, I was golden for the last two sessions on Tuesday.

The belt that failed wasn't stock size but I can't seem to remember the part number as I've misplaced the paperwork. I also have a 15% & 2% crank...

It was on the car since this past April and has seen about 10 autox's and one other HPDE @ Watkins Glen since then...

So what would be the correct belt size and a better brand than Napa??

 

060537

 

I have Gates K060539. My car is stock and I want to replace the belt. Did I buy the right belt? (I got it from OutMotoring, the website says 15% and stock is the same)

Thanks

 

I keep seeing references to a 15% pulley, which one is that and what's the advantage of that pulley over what came on the car.

 

MANY, MANY threads on this! 15% pulley is smaller than the stock supercharger pulley and provides more boost, especially at lower rpms, right where the MINI needs it.

 

Changing to the pulley that is 15% smaller than the stock pulley will spin the supercharger faster and increase the boost by about 4lbs, thus increasing the power output of the engine. This is the biggest bang for the buck you can do to get more power out of a supercharged MINI. It's the most common mod out there. They make some that are 17% and 19% smaller, but the 15% supercharger pulley is the most common.