I was thinking about a supercharger pully upgrade, I have a 2004 Mini Cooper S works. Will I have any problems with a kit?

 

Care to be more clear on the question?
A Works car has a 11% reduction pulley relative to regular OEM, so you don't get much with a 15%

 

Best to stay with a 15% which is the best bang for your buck that you can make to a MINI. You'll love the hp increase. Going down to a 17% makes sense on a track car but not on a street car because it will shorten the life of your supercharger.

 

By far the best bang for the buck upgrade for the R53.

If you have a JCW your supercharger already has a smaller pulley so going to a 17% will show the better improvement as it will be a bigger difference from the stock JCW. This will also gain you more low end torque as you will have more boost on the low end.
https://www.waymotorworks.com/wmw-pulley-package.html

You will also need a JCW specific puller to do the job.
https://www.waymotorworks.com/john-c...uller-r53.html

 

I use 99oct on my S5, as I have a convertible what sort of 0-60 times do you feel I would get? Perhaps increased by half a second 4ish?
Tutuapp 9apps Showbox

 

What is..."4ish"
Half a second 4ish...!?

Mike

 

2994mcw -

Do you have a larger damper? ATI makes a slightly larger damper that is also MUCH better quality than the stock damper. I believe the larger ATI will spin the blower another 2% over.

Mike

 

From a JCW pulley (11%ish) to a 15% pulley is a lot of work for not a lot of gain. Money and time would be better spent upgrading other failure prone components, including the crank pulley (previously mentioned), which you can get over-sized to increase your supercharger RPM.