Jeff4598

I am trying to put together my config for a spring delivery. When I read about CCBs I see comments about decreased dust, track performance and prestige. I am interested in around town handling FEEL. One winter I bought snows for my M3 and got cheap but light wheels. Wheel weight went down about 4 pounds each (wheels were light and cast and bent after 2 winters but that's beside the point here). The lower unsprung mass did absolute wonders for the steering and handling feel despite the less grippy winter tires (up to about 7/10 of course when the tires got loose). Would I not expect to get an even larger improvement in these parameters with CCB's? Why does this never seem to come up? Any experience in this regard out there? Thanks in advance. They are not cheap but people spend even more for forged wheels to decrease weight by a fraction of the decrease with CCBs.

Pep!RRRR

I’m skeptical whether anyone would detect an improvement in handling due to the reduced weight. Also keep in mind that the CCB are much larger than the standard brakes. Are they really even lighter? What I would consider is changing the single piece steel rotors to a lighter two piece design, such as those made by girodisc.

911boy

I'm sure majority of the better "feel" you got was from the winter tires. I put same size winter tires on same wheels for years and always marvelled at different feel. 4 Lbs isn't much.

Crester

4 lbs unsprung weight per wheel is a big difference between 4lbs of sprung weight.

Code

This. I say if you can afford CCBs then by all means do it.

Bacura

I am very happy with my CCB’s. But mainly for the absent brake dust. I don’t track my car so I feel nothing special in daily driving. They will last (me) forever in daily driving but if you track your car consider the replacement cost. Also, I only use the dealer. If an INDY chips your rotor they won’t pay for a replacement disc. When a wheel is taken off my car the dealer documents that they used a special tool to avoid damaging the rotor.

Valvefloat991

I don't know how much unsprung weight there is in the corner of a typical car, but I suspect it's at least 100 pounds. Consider:

Tire
Wheel
Brake Rotor
Brake caliper
Hub/upright with wheel bearings
half of the control arms
half of the shock absorber
half of the spring
half of the tie rod/halfshaft

Mounted 911 wheels and tires must weigh between 45 and 55 pounds alone. Four pounds is helpful, but it's a small percentage difference.

MagicRat

I drove a CCB car and a steel one back to back on a track and then bought the CCBs. Wish in hindsight I’d been led up to the cars with my eyes closed as it was impossible to rule out bias, but the CCB car felt noticeably lighter on its feet to me. Same with two otherwise identical motorcycles I tested recently, one with lightweight wheels and one without. I would say go for it if financially feasible.

ibmiked

It's not 4 lbs per corner but closer to 10 lbs. If you don't think that's significant when it comes to unsprung weight then you missed a few days in physics class.

Courtesy of board member KA Motorsport:

Front OE PCCB (410 x 36, 2-piece) - 15 lbs
Front OE Steel (380 x 34 2-piece co-cast) - 24 lbs

Rear OE PCCB (390 x 32, 2-piece discs) - 13.5 lbs
Rear OE Steel (380 x 30, 2-piece co-cast) - 23.5 lbs

phx991

I believe OP stated that he is "interested in around town handling FEEL." While physics would explain a decrease in lap times, psychology would explain whether someone perceives a difference in feel.

Driving around town, I doubt anyone could tell the difference in how the car feels, and I personally cannot tell the difference. That's not surprising because, as someone already noted, the total unsprung weight is close to 100 lbs per corner, so it's not a large percent change. Also consider that the car has over 2,600 pounds of sprung weight that also contributes to how the car handles.

Pep!RRRR

Are we dealing with an S or Base model? Base standard brakes are considerably smaller and I presume lighter than S.

wareaglescott

There are numerous options on these cars that are completely useless for "driving around town" as it is pretty much impossible to approach the limits driving around town. With that being said if you like the option and thinks it makes a difference go for it! Owning a high end car is pretty much an exercise in excess. None of it is really needed but that doesn't make it any less fun to have it. Sure on the track the unsprung weight difference could be noticeable. If anyone can notice it driving around town then the seat of their pants is way more highly calibrated than mine.

ENCT

I have PCCB's and like them a lot. The lack of dust is a plus and they make the car feel lighter to me. Maybe because I came from a base to a 4S with PCCB's and PDCC?
Eric

RDCR

I tracked my GT4 with PCCBs and then did the Girodisc conversion rotors (which are heavier then the OEM steel 380 rotors on non PCCB GT4s). I couldn't feel any difference from a weight standpoint on the street or track. The big difference was in initial bite, which is substantially greater with PCCBs. Took me a few track days after the conversion to get used to that.

francisluu

Interesting. I find the brakes on my 991.2 GTS a bit touchy. I'd love to be able to press a bit harder at the beginning of the pedal before they bite hard.