I track my 991S several weekends throughout the summer. The car is stock other that Pagid RS29 pads and ATE Gold fluid. During a recent pad change I noticed that the outside rear caliper boots had melted/cracked obviously from excess heat. The replacement was easy and relatively inexpensive, about $35 for four boots.

Now why this happened to just the outside rear boots, I have no idea. My pads are currently about 1/2 used. I run/instruct in the advanced groups so I am fairly aggressive with the brakes. So maybe it's just the way it is.

Anyway, be sure to monitor your boots, guys!

 

The rears in the 991 actually run hotter than the fronts due to the PTV

 

If you buy the Centric rebuild kits, the boots are silicone, which have a higher temperature tolerance.

 

^^^ Great tip. I used the OEM Brembo kits. Do you have a source or part number for the boots you refer to? Thanks.

 

http://store.zeckhausen.com/catalog/...1471_5870_5871

 

Excellent! Thanks.

 

I know we're not supposed to run these cars on the track (according to the owner's manual) but I thought that superior German engineering would have anticipated this kind of heat issue and accommodated it?

 

I totally agree. I moved from a 987 Cayman S to the Carrera S and thought the upgrade in the car would accommodate me as-is for HPDE events. My very first weekend at the track I cracked my rotors and totally destroyed a set of OEM pads. A very expensive lesson. Porsche would cover any of it, even though my dealer was on my side.

So now I run Pagid RS29 pads at the HPDE events and change to stock for the street. Now, in my second season of HPDE events, I am getting ready to replace my second set of cracked rotors. I only run 4-6 events per season.

All the Porsche ads, videos and marketing would have you believe the cars are track ready. It ain't so!

 

good to know. I wanted to take mine out to at least one event to see how it does, but I think I will just stick to my 370z racecar. I took my last daily, an M235i to an event and totally trashed the tires and had to have the front bumper repainted. I clearbra'd the entire front end of this one, but still don't think I will take a chance with it at this point.

 

Interesting to read about the brake problems... I have done 4 track days and only half way down on the stock pads and just flushed the fluid with motul 600. I guess I'm light on the brakes? A clear bra is a must unless there's no one in front of you.

 

Hi Brad:
I run my 991 CS2 in Lone Star Region PCA events. Last weekend I ran three days at COTA (Circuit of the Americas) which has lots of high speed braking areas. I started with front pads used one weekend at TWS in College Station and brand new OEM rear rotors and pads. By the end of the last session both front and rear pads were extremely thin and need to be replaced. Do you have any suggestions for replacement pads that can be used on the street as well as the track.

 

I don't know of a suitable pad for BOTH street and track. I change my pads to Pagid for every track event and (almost) dustless Centric pads for street.

 

I stopped going to the track because the stock pads stand no chance in advanced group speeds, the pagids are loud as hell on the street, and it's too much of a pain to switch back and forth (plus switching to R-comps every time).