[Terry Thomas]

Today I replaced the rear rotors on my 987.2 mostly track car with a set of 325mm Girodiscs. I had done the fronts earlier in the year and was really impressed with the difference they made, both in braking force and heat management. And they appear to be handling the Performance Friction 08 pads nicely, showing little wear or scoring after several tough days at the track.

Although I knew the rears were in sad shape, only when I pulled them off and took a close look did I realize just how far gone they were. Each disc had the usual cracks emanating from the holes, but each also has a crack that went all the way to the edge and on through the disc surface. Nasty, and potentially catastrophic, if the discs decided to shatter at speed during heavy braking.

Now the car has proper brakes at all four corners, and once again all is right in the universe.

 

[Apex1]

Do you have GT2 cooling ducts on your brakes?

 

[Terry Thomas]

I do not. I gather they are worthwhile?

Terry

 

[Croc999]

GT3 ducts at front cost peanuts and plug and play affair.

 

[91Eunos]

Man, you weren't kidding! I replaced my fronts w/Girodiscs earlier this year and had what I consider normal wear/cracking:

...will replace the rears soon, but leaning towards "stock" replacement slotted (not drilled) Sebro rotors. IIRC, the Girodisc rears are a bit heavier than stock...larger diameter though.

And the front GT-3 brake ducts are cheap and easy...cost ~$5 each I think:

 

[Craig911]

Wow TT, those were a near disaster!

 

[Terry Thomas]

Yup, bad things happen when brake discs shatter under heavy braking. I had my eye on these before the last track day, but they cracked more heavily than I anticipated. All fixed ow, though, with the new discs in place.

 

[Craig911]

The rears - pads, caliper, rotors go thru hell on these cars - MUCH more so than 95% of all other makes and models

 

[Terry Thomas]

I think a lot of that is because the traction control cannot be turned completely off with the "PSM off" switch. Even with the switch turned to off, the traction control still operates on the rear brakes. I have solved this problem by installing a switch that turns off the yaw sensor. That does the trick.

 

[Craig911]

Exactly correct - rears get extremely hot....rears can turn purple/brown while fronts look nearly new