STI Rear Brembo
 

Is there any reason that a ~2017 STI rear Brembo caliper wouldn't interchange with a PP rear Brembo? We already know the bolt up to the car fine.

They both use the same Centric rebuild kit for a 40mm piston

https://centricparts.com/part-detail/14335031

They also both use the same DBA dual drilled rotor

https://www.counterspacegarage.com/dba-4000-brz-pp-rear

https://www.rallysportdirect.com/par...otor-pair-rear

This seems to indicate that they're the same offset and the same piston size so there would be no balance change or alignment issues.

Gonna find out ... for science. I ordered a set of reman'd Powerstop calipers and a Centric rebuild kit for each from RockAuto for $115/caliper including $48 core charge each. $15 a pop for the rebuild kits.

Going to measure the pistons when they get here, if it is what I expect (40mm) then I'll disassemble, drop them at my powdercoater for red w/ Brembo logo, and put the Centric seals in them.

They're the same. I assume the confusion comes from people measuring the front of the piston where it contacts the pad, which is 36mm on both the PP and STI rear, or because the orange 04-07 STI rear calipers were 36mm pistons. Pistons are 40mm on both 08-17 STI rear and PP rear.

This is a picture of some, just to help illustrate. The dust seal fits into the groove and effectively hides the full piston size.

https://i.imgur.com/C00hoEW.png

Is the bleed valve still on the top side?

Pretty sure ALL bleed valves are on the top for physics reasons.

Right, but what i mean is the caliper on the same front/back side of the rotor? The BRZ/FRS/GT86, the caliper is on the rear side of the rear rotor. If the sti caliper is on the front side of the rotor originally, then the caliper will be flipped about 90ish degrees so the valve might be on the bottom side if installed on our platform, assuming you can't just flip the side of the car.

Yes

STI caliper uses M10x1.5 38mm bolts instead of M10x1.25 38mm bolts, so watch for that if you're coming from normal sliding calipers or aftermarket rear calipers.

https://i.imgur.com/SfbQMOT.jpg

Rotor is a Centric PP blank, it is centered in the caliper.

Centric 40mm BRZ PP seal laid over the piston, matches

https://i.imgur.com/QBXlE2r.jpg

Nice find!

Thanks, I'd kinda worried about being called out on them for TT5 but I think that would be extreeeemly nitpicky and I think they fall under the functionally identical allowance anyway given that the difference between the two comes down to paint color.

Absolutely. No piston count change or piston diameter change, they bolt up factory and use a stock rotor. Its just a house brand caliper instead of a brembo name. No one would ever protest that.

Should be sticky. Nice find. I was going to replace rear calipers this year, may have to go this route.

It's too bad the STI front is 40/46, there are cheap remans of those too. Still got pay the steep PP front caliper tax.

why not go ats front calipers? Same size pistons as PP kit.

Not sure which ones you mean, this is what I see for front piston sizes for Cadillacs:

04-07 CTS-V - 40/44
09-15 CTS-V - 30/34/38
16+ ATS-V - 30/34/38
16+ ATS - 42/42

PP is 40/40

04-17 STI - 40/46
18+ STI - 30/34/38

The only thing I've really found that matches the PP 40/40 is the FK8 Civic Type R, but the bracket shape doesn't seem right (disclaimer: I haven't measured).

Also, thank you for making me double check, I typo'd the STI front pistons in my other post.

I had a set of these Rockauto ones powdercoated red to match PP.

https://i.imgur.com/WxZsa6e.jpg

oh, odd

https://www.ft86club.com/forums/showthread.php?t=117769

this says the front brembos are 42s

further research looks like 40s though, but his brake calc with ats front and evo x rear (same size as sti rear) puts bias close to stock.

The below are 38/42 brakes:

ACURA

TL: 2004 - 2008
AUDI

R8: 2008 - 2012, 2014 - 2015, 2017 - 2018
DODGE

Viper: 1992 - 2006, 2008 - 2010, 2015 - 2017
FERRARI

360: 2000 - 2005
NISSAN

Sentra: 2004 - 2006
SRT

Viper: 2013 - 2014
VOLVO

S60: 2004 - 2007
V70: 2004 - 2007

Alfa Romeo Giulia 2.0 also has 40/40 brakes. The caliper seems to be a monoblock which would be good. Not sure about offset and adaptor bracket (rotor is 13” instead of 13.8”)