If any one is interested, I did a 05 to 07 brake swap. Rather straight forward except for the bleeding the system which was a pain. I’ve listed the specs of both brakes and did a side by side comparison shot as well. May be a good reference for anyone considering the swap, here’s the link:
http://clubsportz.blogspot.com/2011/...og-states.html

 

Did mine a few months ago, my pedal is not where it used to be. We also used the motive bleeder on it. Took awhile, but did get pressure back in the pedal. Think I might change my Master Cylinder to a larger one. I am not completely happy with the pedal. Works fine, but don't think master cylinder was designed to move extra pistons, have to do some more research. Nice little write up.

 

There is a fairly significant change in master cylinder sizes between base 03-05 and 06+ model brakes, its really not an ideal swap with regards to maintaining good pedal feel although there is a decent bump in heat capacity.

 

Yes, I have to agree brake feel is less than ideal now. I have Stoptech pads and the bite is amazing but pedal feel is not there. Does anyone have the part numebr for the 07 Master Cylinder?

 

Last time i looked it up it was the same as the 03 and the Brembo equiped masters.

 

That’s what I thought, but I was referring to MW9's statement of moving to a larger MC. Is there such a thing?

 

this write up would've been useful a couple months ago when i had the brakes swapped- oh well.

i was also under the impression that the master cylinder was the same. swapped 05 to 08s and brake feel was great, and this considering the fact that i put on pinkish track-used rotors.

on that note, would it really matter that the master cylinder now pushes 2 pistons/caliper as opposed to one, even if it is smaller (as terrasmak and cubic said, i also thought the MC went unchanged 03-08)? the 03-05 single piston has a larger diameter than each piston for the 06+ calipers, the overall pressure across the caliper should be barely more. I figured any possible difference wouldn't be discernible on the street, assuming the brakes were bled properly. there may be a SLIGHT advantage on a track, but these aren't 4+ piston racing calipers where a swap might drastically affect the brake balance.

 

So your pedal feel is good? No issues?

 

pedal feel is fine, no numbness and no problems. maybe try bleeding again? i thought that was the hardest part of the swap. try using a friend pushing the brake pedal on your call instead of using a power bleeder? there is also supposed to be an "order" of bleeding the specific brake lines, check the manual i think. it's something like passenger back, driver back, passenger front, driver front but don't trust my word on that.