Cup Fender Liner - 997.504.123.90 & 997.504.123.93
Air Guide - 997.575.231.91 & 997.575.232.91

 

The complete fender liner as used on the cups has air guides to direct air into the rotors. Its very effective.
That said, I forgot to mention you also need to trim (not remove) the backing plates to expose more of the rotor to the airstream. The backing plates protect the speed sensor and ball joints from the heat.
Couple of thing to note in this pic..
1) The open air channel behind the radiator
2) The air deflectors inside the fender liner that begin to guide air towards the inside barrel of the wheel.
3) The air guide behind the fender liner to really direct air into the barrel of the wheel.
4) You can see a little of how my backing plates are trimmed and gold foil used to protect the plastics electrical junction so I could remove more of the backing plate.
5) Ignore the duct to directly cool the caliper, thats my secret sauce....

 

Thanks for the details on GT3 fender liners and brake ducts.

I was thinking GT4 fender liners, which to my knowledge do not have a dedicated duct to the brakes.
.

 

gt4gt4, cracks in drilled stock rotors are expected. Cracks longer than 5-6 mm, cracks that join or edge cracks should be replaced. Many convert to Sebro slotted for that reason. The Sebro slotted IMO add a larger heat load to the brake fluid. Not a problem for SRF.

 

Lots of great info in here, my car had the GT3 ducts on it when I bought the car (I had actually put those on my VW R32 also), great cheap mod. I am going to need to do a brake upgrade soon, glad to hear that so many like the Sebro rotors, that is what I planned to use.

One thing that hasnt been discussed is the GT3 master cylinder, @jscott82 have you done this on your car?

 

yes 997gt3 MC + 996TT booster improve pedal feel a bit. Not sure i would go out of my way to replace them, but its a good "while you are in there" kind of upgrade.

 

I wanted to add a data point that I used to use ATE type 200 and switched to SRF several years ago after type 200 kept boiling on hot days at high speeds. Never had the fading/boiling problem once I switched to SRF. I have been track driving for about 21 years now on many tracks that range from light to heavy brake use. I am sure Motul 660 and 600 are great, but I have not tried them.

I change my fluid annually. Moving from type 200 to SRF adds about $40+ a year to maintenance, which is well worth it. I get SRF on Amazon and last paid $60 a liter. I have tested the fluid, and annual changes are quite often enough. By the way, I also run OE pads and have not found that specialty pads afford me any significant performance advantage.

I have always run cross drilled discs for the lighter weight, better cooling, and better looks. I am wondering what thoughts are on slotted vs drilled. I notice that I do go through pads relatively quickly and that I get grooving where the holes are in the discs. If I went solid or slotted, I expect I would not get this grooving and the pads would last longer, but how much longer I do not know. Am I really going to miss the cooling, or is this a minor difference? I am curious if anyone switched one way or the other and could really tell a difference.

 

Another data point... I don't care about any spec sheet says, SRF kills the competition and last far longer too. Firsthand experience here. You can't beat it. Absolutely worth the premium over inferior fluids.

 

+! For track use, can't be beat. Ran it in my club race car and never looked back. And that car ate Pagid black pads and frozen Porsche rotors like they were candy. The fluid, however, never disappointed.

For street-only cars, I'm still running the stock fill from Porsche, presumably the Pentosin Super DOT4 stuff. For track work / racing... it's SRF baby!

 

It should be noted that the -93 number(s) are if you have a .2.

I had a few customer's try to order these part numbers in the past several months. Call us if you you would like to order the correct parts.

--Aaron

 

Wow! Another historic thread with a goldmine of useful info!