fhp911

I agree with hoopumpers -- I did upgrade just now to the GT3 master cylinder but let's put things in context -- my stock system 987 system is quite adequate, both for street and track. I never had the pedal sink to the floor or any other problem.

mhm993 (who is a long-standing friend of mine) must have a problem with his setup.

ChrisFL

What everyone is talking about is pedal feel. The brakes are more than adequate to do the job on track. The pedal staying firm is (mostly) fixed with the GT3 master cylinder.
Its slightly bigger than the PCCB so it worth it to get the GT3 one. You can get the "generic" from ECS and save a bunch of money (they actually make the Porsche one and then Porsche brands it and sells its for 2x the cost).

The other issue I believe is overheating of the brakes... some get bigger discs (Girodiscs), GT3 brake ducts help, but I think putting a air duct from the fog light opening to the front brakes are the better solution.

orthojoe

+1

Even though Randy Pobst also felt like it was a spongy pedal from overheat, I don't think it's an issue with the brakes overheating. That's just the way the pedal was designed to 'work'. The reason I say this is because I had the same mushy problem even with 350mm PCCB rotors and massively oversized 6pot calipers. There's no way those brakes were overheating. They never have. At first I thought it was a pccb characteristic, but that turned out not to be the case, obviously.

ECS Tuning

4forme did a DIY and did an awesome job, I posted the link below.

https://rennlist.com/forums/987-981-...-cayman-r.html

ajondyh

Bigger discs are not needed really.

mhm993

Fred. It was a deal breaker if I couldn't resolve it. In brake zones the soft pedal had little feel causing me to keep pushing harder. The brakes worked just fine-- and I found myself deep into ABS all the time. And while I unfortunately have a deep love of braking too much, this was ridiculous. While I probably could have learned to live with it, the firm tall pedal with the bigger MC is just a world better feeling.
The car stopped fine with stock. The driver hated the feel.

orthojoe

Bingo.

mhm993

Ortho
Iirc, it was searching your posts regarding cayman brakes that convinced me of the solution. Many thanks

orthojoe

Glad to hear my ramblings can be helpful! Thanks!

khooni

yeah. for road use it is fine.

on track, you are compromised by the longer, mushier travel (yes Joe, you win) which i must say affects confidence. The PCCB brakes are not bad at all compared to the standard brakes and are in between those of the GT3s.

On the road, it is harder to heel and toe with the GT3 brakes, which I presume is why porsche did it for the spyder/Cayman. For road only use, I wouldn't switch it if you heel and toe. If you don't , it doesn't matter....

orthojoe

I am humbled, khooni.

Now, if only mrd_spy would join the dark side...

fhp911

Just drove my '11 Boxster S with the GT3 master cylinder installed for the 1st time.

Pedal feel is *completely* different -- was apparent at the first stop sign. Formerly the pedal would sink a bit before much happened -- now the brakes bite as soon as you touch the pedal. Whether actual braking performance is any better, I don't know.

I never suffered loss of confidence on the track with the stock setup -- I trusted it, but this does seem like a worthwhile investment.

khooni

who did the upgrade for you in the end?

ajondyh

My local OPC supplied and fitted it for me.

AP997S

I want to do the GT3 master cylinder upgrade on my early build 2014 Cayman S (981S). Does any know if GT3 part number 99135513080 is the correct master cylinder. I believe there is 2 versions (w and w/o a brake light switch).

Thanks in advance for any help.