BRZ/FRS big brake kit vs WRX counterparts: brake piston size (differences, if any)?

[mav1178]

Hi everyone,

I'm trying to get some info on this, but would appreciate a definitive answer.

I know the WRX/STi brakes are a direct swap over to the FRS/BRZ (minus the swapping of bleeder valve), but wanted to know:

Are the front caliper pistons the same between the two? And any proportioning issues?

Wilwood site seems to suggest the two are identical, not sure if anyone else has found any contradicting info.

Wilwood FRS/BRZ:
http://www.wilwood.com/BrakeKits/Bra...BRZ&option=All

Wilwood WRX:
http://www.wilwood.com/BrakeKits/Bra...eza&option=WRX

The piston area, brake pad area, and brake pad volume are all identical between the two cars.

Thanks in advance.

-alex

[mav1178]

Bump for visibility.

-alex

[OrbitalEllipses]

WRX front OEM equipment should be the same or nearly identical. Our rear setup comes from the 2010 LGT...which as far as I can tell also has the same piston diameter as the WRX, but I'd have to confirm that as I'm going off memory.

Bias/proportioning: the 2002-2005 WRX and 2004+ STI have always been heavily front-biased; those are front-heavy AWD cars so that makes sense. The 2006-2007 WRX had more refined brake bias front to rear and that brake setup is highly regarding as a not so costly, but effective "BBK" for other Subarus. Regarding the STI: these Brembo opposed piston calipers can be mounted, easily, to our cars. Reasonably large rotors. Mounting the Brembo setup will move bias forward; there is a spreadsheet from NASIOC that has these and many, many more details. Very different from any OEM Subaru offering except perhaps the 2006-2007 WRX setup.

Regarding the above posted Wilwoods: never liked Wilwood BBKs. @swift996 is running the WRX 4pot kit on his BRZ. Also, the rotor diameters are slightly different between those two 6pot kits, that will alter bias slightly with the larger rotor creating more torque. Note the WRX kit is the one with the larger rotor, that is a heavier car - more specifically - front heavy.

[swift996]

Yup I am running the 4 pot Wilwood WRX kit. The BRZ kit is a 6 pot with a larger diameter and width. The car was pretty neutral bias with street pads but when you step up to race pads it becomes a little harder to match compounds to keep a neural bias. My front's bite hard (running Wilwood BP-30 race pads) and Carbotech XP-10s in the rear.

I'm use to it and for the money it was worthwhile for me. Not sure if just swapping pads would be more bang for the buck though.

[mav1178]

Originally Posted by OrbitalEllipses

WRX front OEM equipment should be the same or nearly identical. Our rear setup comes from the 2010 LGT...which as far as I can tell also has the same piston diameter as the WRX, but I'd have to confirm that as I'm going off memory.

Thanks for the info.. not running the Wilwoods, actually.

Came across a deal (potentially) for a set of Endless big brake kit. It's coming off a WRX, hence the question.

Originally Posted by swift996

Yup I am running the 4 pot Wilwood WRX kit. The BRZ kit is a 6 pot with a larger diameter and width. The car was pretty neutral bias with street pads but when you step up to race pads it becomes a little harder to match compounds to keep a neural bias. My front's bite hard (running Wilwood BP-30 race pads) and Carbotech XP-10s in the rear.

I'm use to it and for the money it was worthwhile for me. Not sure if just swapping pads would be more bang for the buck though.

My main concern is keeping the braking balance of the car with a brake kit for the WRX fitted to the BRZ. I know it'll fit, and I know it works fine for normal braking conditions, I want to know the balance under actual track use.

If it's neutral under street pad use, then that's an easy fix

Much appreciated!

-alex