Planet 9

jeffreybehr · #1 06-05-2009, 10:52 AM

Since the caliper mounts so simply...what I'll call semiradially...seems it would be easy to install a larger rotor while retaining the original caliper, with a spacer, new screws, perhaps with a few new fittings, etc. Does anyone know of such a system? I'd LOVE bigger front brakes, but I'm not yet ready to spend US$3K+ on a, say, Brembo system from LPI... porsche brembo: porsche brake kit - porsche brake upgrade - porsche big brake - porsche brake conversion

**Craig@Rennstore.com** · #2 06-06-2009, 02:16 PM

Exactly - they are radially mounted so it is extraordinarily easy to install a *properly engineered* larger rotor setup.

PORSCHE CAYMAN ROTOR PACKAGES
SIZE:
Front: Factory 317 mm/GiroDisc 340 mm
Rear: Factory 298 mm/GiroDisc 325 mm

WEIGHT:
Front: Factory 19.85 lbs./GiroDisc 17.25 lbs.

Rear: Factory 14.0 lbs./GiroDisc 15.00 lbs.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The GiroDiscs make the most sense:

Price: Under $2300 for a COMPLETE 4 CORNER Cayman S setup

Performance: No more holed rotors, slotted last MUCH longer + floating design + larger diameter for additional thermal capacity

Shoot me a note if you need additional information -

**Craig@Rennstore.com** · #3 08-12-2009, 01:48 PM

FREE UPS Ground shipping now -

Jim Michaels · #4 08-12-2009, 03:05 PM

What's the braking gain with larger rotors while retaining the same calipers and pads?

jeffreybehr · #5 08-12-2009, 03:49 PM

Originally Posted by Jim Michaels

What's the braking gain with larger rotors while retaining the same calipers and pads?

Larger rotors dissipate heat faster/better.

And they look better, too.

**Croc'ed** · #6 08-12-2009, 04:37 PM

Originally Posted by Jim Michaels

What's the braking gain with larger rotors while retaining the same calipers and pads?

Same clamping force [from the stock caliper and pads] X Longer lever arm [by moving the caliper radially away from the wheel center] = Greater braking torque

**Craig@Rennstore.com** · #7 08-12-2009, 04:54 PM

Exactly.

Lever arm: This is precisely why race teams use such large calipers with a short annulus (swept width)

Size: Much better heat sink

AND: These are SLOTTED. Last a hell of a lot longer than OEM with all the cracking and grooving issues!

***Speedy*** · #8 08-13-2009, 07:46 AM

Craig,

This has probably been covered before, but if you don't mind me asking - will the GiroDisc rotors fit behind the stock 18" Cayman S wheel?

Thanks.

**Craig@Rennstore.com** · #9 08-13-2009, 11:19 AM

Definitely will, no issues whatsoever.

**jaica** · #10 08-13-2009, 12:41 PM

I will chime in. I have a Girodisk set, and they have been working great. I can outbrake just about anyone at the track, (except some dedicated track cars that weight a lot less, say 2200 pounds). No fade with Motul 600, flushed once a year and bled after every event, and braided brake lines. Easier modulation than the originals. Our original brakes are very good to begin with. I would not have bothered for autocross.

**Craig@Rennstore.com** · #11 08-13-2009, 12:55 PM

You also drive your car is extremely hot conditions too, correct?

**jaica** · #12 08-13-2009, 03:16 PM

The temperatures in the summer fluctuate from 95 to 100 at the track with the sun beating on the tarmack. In the so call winter it is 80 to 90 degrees at the track. It is a lot cooler in the mountains and somewhat cooler in the north coast where I live.

**Craig@Rennstore.com** · #13 08-13-2009, 03:53 PM

Data point:

There are 2 father/son track duos here who both had probelms pre-GiroDisc, no problems any longer.
Cars run all day, back-to-back sessions with 1 break at lunch.

canIray · #14 08-13-2009, 11:27 PM

do these rotors not fit on the non S cayman?

lspain · #15 08-14-2009, 06:53 AM

How about unsprung weight? Recognizing that it takes a pretty good driver to see any difference, is there a difference in handling that comes from this type of setup?

edit: Craig, I'm sure you've covered this before but it might bear repeating here.

**Craig@Rennstore.com** · #16 08-14-2009, 11:39 AM

Not avail for non-S which has a completely different caliper & rotor.

Here are the stats regarding size & weight:

PORSCHE CAYMAN ROTOR PACKAGE
SIZE:
Front: Factory 317 mm/GiroDisc 340 mm
Rear: Factory 298 mm/GiroDisc 325 mm

WEIGHT:
Front: Factory 19.85 lbs./GiroDisc 17.25 lbs.
Rear: Factory 14.0 lbs./GiroDisc 15.00 lbs.

**Craig@Rennstore.com** · #17 03-11-2010, 03:10 PM

UPDATE: FREE shipping on GiroDiscs!

*Must mention when ordering...anywhere in the USA via UPS*

Jeff G in NE GA · #18 03-11-2010, 06:08 PM

Originally Posted by Craig@Rennstore.com

PORSCHE CAYMAN ROTOR PACKAGE
SIZE:
Front: Factory 317 mm/GiroDisc 340 mm
Rear: Factory 298 mm/GiroDisc 325 mm

WEIGHT:
Front: Factory 19.85 lbs./GiroDisc 17.25 lbs.
Rear: Factory 14.0 lbs./GiroDisc 15.00 lbs.

They look very nice.
Do you have any actual rotational inertia info (since the weight was saved in the hat)? Thanks.

**Craig@Rennstore.com** · #19 03-11-2010, 08:46 PM

You bet - here she is:

PORSCHE CAYMAN ROTOR PACKAGES

SIZE:
Front: Factory 317 mm/GiroDisc 340 mm
Rear: Factory 298 mm/GiroDisc 325 mm

WEIGHT:
Front: Factory 19.85 lbs./GiroDisc 17.25 lbs.
Rear: Factory 14.0 lbs./GiroDisc 15.00 lbs.

intubator · #20 03-11-2010, 08:57 PM

Craig, do you have the size specs for the factory Cayman S PCCB's?