I am considering an underdrive pulley kit for my 2006 XKR. I was wondering if anyone has done this and if made a noticeable difference in performance...Also curious about any other performance modifications and their results...Thanks for any input...

 

There are numerous threads in this section of the website dealing with pulley replacement, tuning, exhaust systems, etc. Suggest you do a search in the search box above regarding those things that you are specifically interested in. Also, you should register as a new member.

 

Thanks