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Essex/AP Racing 2-piece J Hook Brake Discs and Ferodo Racing Brake Pads for GT4
Hello Gents,
AP Racing J Hook Discs
I know some of you are aware that we recently released two-piece AP Racing J Hook discs for the 991 GT3. You can see all of the details in this thread. I've had a number of future GT4 owners call me about discs for their cars.
Everything we've seen from Porsche thus far has suggested that the front and rear brakes on the GT4 are identical to those on the GT3...same calipers, same pads, same discs. Can anyone who has taken delivery of their car confirm that information? Or, if anyone can please verify that the Porsche part numbers for the front and rear discs are identical across the 991 GT3 and GT4 platforms. We are particularly interested in the iron discs, which measure 380x34mm front and 380x30mm rear.
Below are a few photos of our discs:
Ferodo Racing Brake Pads
Also, can anyone verify that the GT4's front and rear pad shapes are the same as the 991 GT3? We have Ferodo DS1.11 endurance racing pads available now (and Ferodo DS2500 street/autoX compound), and we'd like to see if they'll fit the GT4. Drawings with dimensions can be found here:
Front Ferodo Brake Pad for 991 GT3: FCP4664W
Thanks to anyone who can help us. You can email me, or call me at 704-824- six zero three zero. If you can help us with this info we will be grateful, which could significantly improve your car's future brake performance and longevity!
__________________
'09 Carrera 2S, '08 Boxster LE (orange), '91 Acura NSX, Tesla Model 3 Performance, Fiesta ST
Jeff Ritter
Mgr. High Performance Division, Essex Parts Services Essex Designed AP Racing Radi-CAL Competition Brake Kits & 2-piece J Hook Discs Ferodo Racing Brake Pads Spiegler Stainless Steel Brake Lines
704-824-6030 jeff.ritter@essexparts.com
Would the hat have to be adapted to work with the GT4's 5-lug wheels rather than the GT3's centerlocks? Looking at the images you posted, it appears you've already got two sets of 5 holes in the GT3 hat, the larger of which seems to be used to bolt the assembly to the hub and the smaller being used for something I can't identify. If I hadn't seen the picture of your rotor on the car and didn't know this was a GT3 rotor, I'd have figured that the larger holes were for the wheel lugs and the smaller ones were for bolting the assembly to the hub.
All I got from my dealer when I checked was the attachment.
Thanks! From that doc:
At Porsche, superior driving performance also includes providing the right brakes. They too
come from the 911 GT3, and they offer ample reserves due to their large size. The brakes
feature fixed aluminium monoblock callipers with six pistons each at the front and four
pistons each at the rear. The front and rear brake discs all measure 380 mm in diameter,
so compared to the Cayman GTS, for example, they are 50 mm larger (front) and over
80 mm larger (rear). Not only that: to reduce unsprung masses, the brake discs are made
of a composite material, and their design is derived from motorsport. Overall, they are
around two kilograms lighter than comparable conventional brake discs. The friction rings
are made of grey cast iron; stainless steel pins are used to join them to the aluminium brake
chambers. The Cayman GT4 also has a specially developed cooling system for the brakes.
In front, cooling air is routed to the brakes by guide vanes and spoilers at the wishbones.
Special brake cooling air channels were developed for the rear wheels which ensure effec -
tive flow of cooling air.
The PCCB ceramic brakes, which can be ordered as an option, are also larger than those
in other Cayman sports cars. The perforated and internally ventilated ceramic composite
brake discs are 410 mm in diameter at the front wheels and 390 mm at the rear. They
match those of the 911 GT3. Along with the benefit of extremely low weight, the ceramic
brake discs immediately develop very high and, most importantly, constant friction values
during braking.
Yep...sounds like they're they same brakes...good news! ExMB just scored some favor points.
Would the hat have to be adapted to work with the GT4's 5-lug wheels rather than the GT3's centerlocks? Looking at the images you posted, it appears you've already got two sets of 5 holes in the GT3 hat, the larger of which seems to be used to bolt the assembly to the hub and the smaller being used for something I can't identify. If I hadn't seen the picture of your rotor on the car and didn't know this was a GT3 rotor, I'd have figured that the larger holes were for the wheel lugs and the smaller ones were for bolting the assembly to the hub.
Great minds...I was thinking the same thing. In addition to the centerlock opening, the GT3 has the studs/pins on there to locate the disc. Those holes in our disc hats may be in the proper location, but they may be a bit different in size. If I remember correctly, the ones on the 991 Turbo and GT3 discs are different sizes. We really need to get our hands on one front and one rear GT4 disc. The first person to get me one of each will be very glad they did.
I forgot to say...I'm horribly, horribly jealous of those of you getting a GT4! It's one of the few cars of the past decade that I've really lusted after. Congrats to all of the new owners!
We really need to get our hands on one front and one rear GT4 disc. The first person to get me one of each will be very glad they did.
Bah, my build isn't until November. Somehow I have a feeling this question will be resolved before my delivery. Oh well, in that case I'll just remain optimistic that the solution will be ready by the time I've got mine. Thanks for taking care of us!
Fwiw, in the interview Evo did with Preuninger, he said that the hubs come from the Turbo, so if you've already got a hat for that setup, you may already have the right hole pattern, although the rest of the Turbo's hat design may not be suitable for the GT3 friction ring.
Yep...sounds like they're they same brakes...good news! ExMB just scored some favor points.
Great minds...I was thinking the same thing. In addition to the centerlock opening, the GT3 has the studs/pins on there to locate the disc. Those holes in our disc hats may be in the proper location, but they may be a bit different in size. If I remember correctly, the ones on the 991 Turbo and GT3 discs are different sizes. We really need to get our hands on one front and one rear GT4 disc. The first person to get me one of each will be very glad they did.
Originally Posted by jphughan
Fwiw, in the interview Evo did with Preuninger, he said that the hubs come from the Turbo, so if you've already got a hat for that setup, you may already have the right hole pattern, although the rest of the Turbo's hat design may not be suitable for the GT3 friction ring.
The whole pattern should be on a 5 x 130 circle. AFAIK the only Porsche that doesn't have that bolt circle is the Macan.
I think member Petevb mentioned something about the fact that the 991 Turbo uses the same size rotors, diameter and thickness, but wasn't sure if the hat/rotor combination matched up with the GT3 when discounting the CL vs 5-lug setup. Maybe even some differences internally to the rotors - air flow????? Either way, the 991 Turbo rotors seemed to be priced cheaper than the GT3 by a margin.
But then again we know Porsche and something therefore will have to be different enough to warrant the pricing difference.
06-05-2015 | 12:19 PM
Essex/AP Racing 2-piece J Hook Brake Discs and Ferodo Racing Brake Pads for GT4
