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Need a little brake rotor education - 380 vs 350mm options
So right off the bat...I am coming to you from the Cayman forum because I figure this group will have more insight given Im retrofitting GT3 brake calipers on my 987S. When I get out of my Dad's GT3 or Spyder...I cant get over the lack of braking power in my 987 in comparison. I just picked up 380mm conversion kit for the Cayman using OEM PCCB calipers. Now I am trying to figure out my rotor options. The Cayman is not a track car...it might get a track day once every few years. It seems like there are copious options for 350mm rotors; less so for 380mm. Basically, what I want to know is if I can simply fit 350mm rotors using these calipers? Or do I have to stick with 380mm?
someone else should answer this but if you put the spacers to accept larger disks and the calipers grab the outside of the disks (which they do) then you would need to stick with the larger disks, unless you remove the kit.
surprised that you feel your brakes are not adequate on street. I would investigate what pads and disks your car has. going to the larger disk will only help with cooling not amount of area of friction (for lack of better term).
someone else should answer this but if you put the spacers to accept larger disks and the calipers grab the outside of the disks (which they do) then you would need to stick with the larger disks, unless you remove the kit.
surprised that you feel your brakes are not adequate on street. I would investigate what pads and disks your car has. going to the larger disk will only help with cooling not amount of area of friction (for lack of better term).
I dont expect much different in braking performance for the driving I am doing between 380 and 350. I have jumped from PCCBs back to steels and vice versa and pedal feel/braking performance is outstanding for both. However, there is a big difference from what the 987S came with vs. the GT3 caliper/rotor (either steel or PCCB). The 6-pots have much larger pad area than the Cayman's OEM 4-pots.
My brakes arent bad...but they arent at the level of the GT3, Turbo or 981 Spyder. Pedal feel is good with the GT3 MC but even with Pagids I can tell difference in overall braking performance. Like you said, overkill for the street but my CS is setup like a club sport of sorts and would like the larger brakes and better stopping power.
Before installing a mish-mash of parts on the car, you may want to consider a complete system that was designed specifically for the 987. If you're aren't adding forced induction, a 355mm disc is all you'll ever need. Adding 380mm discs is going to considerably increase your unsprung weight. Our AP Racing Radi-CAL system shaves 4 lbs. unsprung weight vs. OEM 987 components despite being larger. It has a huge range of pad options. Spare iron discs are reasonably priced, and everything in the kit was explicitly designed to shrug off as many track laps as you'd ever want to throw at them. They won't change color with heat, and they will integrate perfectly well with your OEM rear brakes. Our system is a bit more expensive up-front, but it also holds its value a lot better than a jumble of parts. Most customers recoup about 65-70% of the kit cost when they sell ours on the used market. That's after beating them up for a few years on track. Thanks for your consideration.
If you do decide to go to a 380mm disc, we have 380mm discs that replace the OEM 997 GT3 units. Our AP Racing J Hook discs have the greatest longevity of anything on the market. We keep a large supply of spares on hand for accessibility, and our spares prices are very reasonable. Our suggestion would be to mate them up to a good set of Ferodo Racing pads. Again, we're not the least expensive option, but our AP Racing discs are the same ones that are winning the 24 Hours of Le Mans, NASCAR Cup Championships, etc. On top of that, they even look cool.
Here are some Porsche-specific examples: Porsche 991 GT3 owner- "These rotors were first on my GT3 then on my GT3RS, and we had 2 drivers on them for 2 summers. That equates to 70 track days at Mont-Tremblant...Lots of the sessions were back-to-back 20-25 min sessions, so 40-50 minutes straight with just a quick driver change in the middle. These rotors were used with Hoosier R7 and Pirelli DH slicks. Just a great combo!"
Porsche 981 GT4 owner- "I've been happily running the Essex/AP Racing rotor on my Cayman GT4 for a few years now. The reason I'm reaching out is that my current front rotors have seen 23 days at Circuit of the Americas running in the advanced student and instructor run groups...My dilemma is that 23 track days intuitively seems like a lot for a single set of rotors, and yet your article seems to suggest that they may yet have a fair amount of life in them."
Porsche 991.2 GTS owner- "This brake setup was amazing on the track. 0 Fade, 0 heat issues, smooth stopping, good bite. Just all around perfect upgrade! Highly recommend getting these rotors for an upgrade!”
__________________
'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
If i remember correctly, i think that only changing the mastercylinder will help.
The 997 turbo and gt3 are the same ,i think.
You can do a search, here on rennlist
If i remember correctly, i think that only changing the mastercylinder will help.
The 997 turbo and gt3 are the same ,i think.
You can do a search, here on rennlist
I have a GT3 master cylinder. It significantly changed pedal feel. Well worth it...still looking for better braking performance.
Before installing a mish-mash of parts on the car, you may want to consider a complete system that was designed specifically for the 987. If you're aren't adding forced induction, a 355mm disc is all you'll ever need. Adding 380mm discs is going to considerably increase your unsprung weight. Our AP Racing Radi-CAL system shaves 4 lbs. unsprung weight vs. OEM 987 components despite being larger. It has a huge range of pad options. Spare iron discs are reasonably priced, and everything in the kit was explicitly designed to shrug off as many track laps as you'd ever want to throw at them. They won't change color with heat, and they will integrate perfectly well with your OEM rear brakes. Our system is a bit more expensive up-front, but it also holds its value a lot better than a jumble of parts. Most customers recoup about 65-70% of the kit cost when they sell ours on the used market. That's after beating them up for a few years on track. Thanks for your consideration.
If you do decide to go to a 380mm disc, we have 380mm discs that replace the OEM 997 GT3 units. Our AP Racing J Hook discs have the greatest longevity of anything on the market. We keep a large supply of spares on hand for accessibility, and our spares prices are very reasonable. Our suggestion would be to mate them up to a good set of Ferodo Racing pads. Again, we're not the least expensive option, but our AP Racing discs are the same ones that are winning the 24 Hours of Le Mans, NASCAR Cup Championships, etc. On top of that, they even look cool.
Here are some Porsche-specific examples: Porsche 991 GT3 owner- "These rotors were first on my GT3 then on my GT3RS, and we had 2 drivers on them for 2 summers. That equates to 70 track days at Mont-Tremblant...Lots of the sessions were back-to-back 20-25 min sessions, so 40-50 minutes straight with just a quick driver change in the middle. These rotors were used with Hoosier R7 and Pirelli DH slicks. Just a great combo!"
Porsche 981 GT4 owner- "I've been happily running the Essex/AP Racing rotor on my Cayman GT4 for a few years now. The reason I'm reaching out is that my current front rotors have seen 23 days at Circuit of the Americas running in the advanced student and instructor run groups...My dilemma is that 23 track days intuitively seems like a lot for a single set of rotors, and yet your article seems to suggest that they may yet have a fair amount of life in them."
Porsche 991.2 GTS owner- "This brake setup was amazing on the track. 0 Fade, 0 heat issues, smooth stopping, good bite. Just all around perfect upgrade! Highly recommend getting these rotors for an upgrade!”
Have to say the Essex and AP package is the best going by far! we are running PFC 011 pads with SRF and they are mighty
10-21-2020, 12:02 PM
Need a little brake rotor education - 380 vs 350mm options
