I am running the Brembo BBK. and the biggest problem was wheel fitment.
you need to be running at least a 45 offset wheel (probably one without a lip).
and even then have to double/triple check caliper clerance.
I ended up running a .25mm spacer so my OZ would clear.
upsides:
- reduced un-sprung weight on the axle. Each caliper is half the weight of stock caliper. Stock calipers are heavy as hell.
- more stopping power only if you upgrade the tires.
- kit comes with steel braided lines
- less brake fade / better pedal feel for extended sessions
- changing pads takes 10 minutes. remove clip, slide out...slide in. DONE
http://www.youtube.com/watch?v=OOyvGpIOCNw
-decreased stopping distance once you upgrade the tires..into 245 or 255 range....you thought stock setup was good ?
your eyes are gonna pop-out!
downside:
- you will have to replace stock studs - depending on your spacer size.
HR spacers come with extended studs- fyi.
- wheel clearance issues + have to spend $60 on set of hub-centric/ correct bolt pattern spacers, or you will get shudder with non-hub centric spacers like I did.
Now there have been extended threads on several forums about how x-drilled rotors crack and proven with pics etc.
However, I have been talking to several folks at HAWK and Brembo and they all agree that a x-drilled rotor with a good cast and right hole size. don't just crack. unless its past its life...and past their life, all rotors crack. that said, x-drilled rotors may have a shorter life span vs plain/vented rotors.
and I can't wait for someone to introduce carbon rotors to track enthusiast market...further reduce un-sprung weight.
let me add something else here:
I was that guy who was always going "oMG....those wheels cost $1200 ???"
but I learned...that you're paying for reduced wheel weight and reduced unsprung weight and reduced rotation mass/weight.
If you are performance minded...save save save..and get a good wheel. Work, volk, Gram lights...whatever...get a light wheel.
Also, rotora kit requires less clerance...and is preferred by most.