mdrums

You need GT3 front calipers....then everything will work as a true upgrade.

Hatzenbach

Nope,

GT3 calipers have a different offset.
What you meant to say is that I need Turbo calipers

mdrums

You need gt3/turbo..front calipers...they are the same FYI....and 350mm turbo (offset) rotors then you'll have a true brake upgrade. I know this from experience in having done this with my car...I'm not lying to you. This is a easy direct bolt on....throw the silly caliper spare away and get the 6 piston gt3 calipers....search the forums I've posted a lot about this. Still don't believe me then call John at BGB Motorsports and ask him...he won a championship on these same brakes.
See ya .....Mike

Wolfk

Hatzenbach,

In regards to your original inquiry, I noticed while working on a c6 Corvette, the rear factory discs were larger than the calipers leaving an unswept area, much like your dilemma. These areas were painted hub color, no rust rings.

M3 Defector

I have had the Giro discs for nearly a year, PFC 08s and several track days now. No ugly rust ring.

Hatzenbach

Thanks,

that was the answer I was looking for :-)

Hatzenbach

Mike,

so here's the part I don't understand:
My whole "brake odyssey" started when I ordered 350 mm GT3 rotors and then figured out that the offset on the rotors was wrong
(by the way: "reasonably priced" slotted GT3 front rotors anyone?).
So if the GT3 calipers and the Turbo calipers are the same, that would mean that both the Turbo and GT3 rotors have a different offset

- OR -

Does the Turbo/GT3 upright have a different offset?

Let's ask the question differently:
I now have the Girodisc 350 mm rotors on my car and I have the GT3 rotors in a box in my garage.
If I'd replace my stock caliper with a GT3/Turbo caliper which of these two rotors will fit? (it can be only one, that's for sure)

Wolfk

Hatzenbach, I am interested in seeing a photo of your current setup, large rotors, small calipers. I think many would be interested in the big brake look without the expense of big calipers. Of course, the correct way to go is to add the larger caliper also. But some of may be just interested in your setup just for the aesthetics.

Surely, the unswept areas of your Girodiscs are going to rust, M3 Defector states his are not rusting, but he most likely has proper sized calipers.

To answer your question about which rotor will fit with what caliper, I can not answer. Surely someone else can.

Have you noticed a difference in braking feel on the street with your current setup? I know you said you have shutdown track time for this year.

Hatzenbach

Pictures attached.

You can see that I used new rotors and old pads, the pads are not totally "worn in" yet, so the swept area has some areas which aren't shiny yet.
There's no difference in braking power, I also didn't expect any, my concern was heat dissipation.

By the way my statement about two "rings" was wrong. There's only one ring on the inside (it's about 1/4" ~ 1/3" wide). And the brake pads have a very small "eyebrow".

Wolfk

Cool, very nice. The unswept area is barely noticeable.

mdrums

GT3 and Turbo 350mm rotors have different offset. The calipers are the same. So just guy the better 6 piston GT3/Turbo caliper and the 350mm Trubo rotor (has correct offset) and you are good to go.

Also the 6 piston calipers stay red for a lot longer...like years...instead of over heating and turning dirty dark looking like the small 4 piston calipers do. Checker your piston seals on your calipers...they are probably cracked and or missing by now seeing how the color of your calipers shows signs of severe over heatings.

scorcherjf

I'm planning on upgrading to the Girodiscs as well and was wondering about the brake pad swept area. I know there will be an unswept area along the inner side near the hub, but how do the pads fit on the outer edge of the rotor? The caliper spacers they sent me say 12mm on them, which would seem like they would cause the brake pads to extend 2mm beyond the edge of the surface (330mm original diameter, 350mm girodisco diameter, so 20mm difference, 10mm from center - why don't they include 10mm spacers instead?).

A similar RacingBrake kit does the same and they note this happening, was just curious if this happened for you with the Girodisc setup as well?
http://www.racingbrake.com/Porsche-9...m-p/2179-k.htm

Cloudspin

I've used the 350mm Giros rotors with PFC08 pads on my 997.2 C2S for several years now. Attached are front and rear rotor photos while my car was up on a lift. I don't know how many track days they'd been on there but do know the rears had seen more than twice as many days as the fronts.

Cloudspin

I'm not very adept at posting photos and hit submit reply too soon. The only times I get a band on the rotor are immediately after changing pads or discs. It is only temporary though and disappears a few heavy braking events. If you do go with the Giros, I strongly recommend changing your caliper bolts to studs and nuts. I had a bolt pull out of the upright at Sebring soon after having the Giros installed. The caliper came loose and wedged in the wheel well bringing that wheel to an immediate stop. I had just come into the pits fortunately or it could have been very dangerous. As it was I just missed one of the Stevenson Camaro GS cars that was about to head back out on track. No issues after changing to studs and nuts even after multiple disc changes.

Heat dissipation was one of the OP's concerns that led to him going to Girodiscs. Front brake cooling can be enhanced with the addition of GT3 fenderliners that divert air from the radiators from flowing downward and instead flow across the rotors. It is not cool air per se but it is a large volume of air and much cooler than the rotor temps. I don't have the part #'s but have attached photos below.

Girodiscs are one of the best mods I have made to my car. I live in South Florida and do track events all summer. The rotors in conjunction with the pads, braided steel lines and Castrol SRF fluid have eliminated heat related brake fade as a concern for me.

scorcherjf

Thanks for the pics, can't wait to get mine installed. Did you notice the brake pads protruding over the edge of the rotor like this at all? http://www.racingbrake.com/v/vspfile...79-k%20(2).jpg

Do you remember what size spacers they included for the caliper? (I believe it had a label on the spacer itself)