Mike in CA

Put my track wheels/tires on the car yesterday to put them through an initial gentle heat cycle then took them off again to let them rest. While switching them back and forth with the street wheel/tire combo I decided to weigh them.

Stock Carrera Sport w/Pirelli P Zero's
F 19x8.5 235/35/19 46lbs
R 19x11.5 305x30x19 61lbs

Track Carrera IV (standard 2009 Carrera wheel) w/Michelin Sport Cups
F 18x8 235/40/18 44lbs
R 18x10.5 295/30/18 49lbs

I expected the track combo to be lighter than stock due to the smaller and slightly narrower wheels, the half tread depth on the MPSC's, and the rear tires are one size smaller, but still I was really suprised at the 12 pound diffference per tire at the rear. That's a lot of unsprung weight!

utkinpol

61lbs is a lot. My rear 19x11 rims are at 27lbs which I consider to be quite heavy and with PS2 tires they weight 55lbs.

But it is a challenge to find 19x11 rims with weight close to 20lbs. Usually it is about 24lbs so I guess there is not too much to do here unless you move to ultra light 18" rims this will be well under 20lbs.

RonCT

44/49 isn't bad for a track set. I think my 18" forged Volks (8.5 and 11) with RA1s are the same. Real cups are very light, stock tires, no so much so.

According to my chart, 235 Cups are 22 lbs and 295s are 25. RA1s in 245 are 26 and 305 are 32, though I get them shaved so that takes of a few lbs each.

Mspeedster

Given the 2 lb delta of the fronts, the rears are shockingly heavy. I wonder how much of the 12 lb delta is the rim vs. tire?

Mike in CA

The Tire Rack lists the weight of the PZero 305x30x19 at 31 pounds. I searched back through the archives and found the Carrera Sport 11.5x19 at 29lbs 4oz. The TPMS transmitter, valve stems, and wheel centers weigh a few ounces so I guess my bathroom scale was fairly close at 61 lbs.

By contrast, the Michelin Sport cups in 295/30/18 weigh just 25lbs according to TR. Don't have a seperate official weight for the Carrera IV 10.5x18 but looks like they are fairly light at a bit less than 24 pounds based on my finding. (My track tires don't have TPMS or wheel centers, FWIW)

Bottom line, those big 305 Pirelli tires and wide 19" rear Carrera Sports are pretty heavy.

Edgy01

Use PCCBs and you can shave off a lot of unsprung weight there.

Mike in CA

There's some difference of opinion over whether PCCB's are the best choice for track use. I think they're cool, regardless, but with a $16K+ cost to change, I could probably do a lot better on the cost to performance ratio front.

Edgy01

Soon there will be some lighter weight Fuchs wheels available for the public. Drop forged, and single piece. Porsche switched to pressure cast many years ago for financial reasons and they have added to the unsprung weight issue. Give the Fuchs Racing (Fiuchs USA) guys another month or two for them to be out. For a sample of what they sort of look like, check this out:

(various paint schemes will be available)

jnx

WOW, then nobody would notice those pretty yellow calipers.

Edgy01

I may spray them black to hide them!

mdrums

For a daily driver and a couple track days a year don't worry about the weight and I bet you if you put wheels that were 5lbs lighter on you would not notice the difference. My CCW/Toyo RA1's are lighter than my stock wheels and on the street I can not tell any better braking or accelleration.

For tracking the car I would be very leary about the expense and performance of PCCB's. They are cool, hi-tech and all but price vs performance is no where in the ballpark unless you have money to burn...replacment rotors are over $15k! None of the race series use them and the series that allows them they are replaced with steel Brembo's.

Edgy01

Check the 997GT3 forum. The opinions now favor ordering a GT3 with the PCCBs--without them is going to make for a lesser car.

Mike in CA

I think that's good advice. I'm actually fairly pleased with the weight of my track wheels/tires relative to the stock setup; I could have spent a lot more and not had a major, noticeable improvement as you point out.

RonCT

The opinions have nothing to do with track performance, rather marketing desire. In no way did I find my 997 GT3 with steel brakes any lesser than those made with PCCB. If I were to order another Porsche, which based on my history of 3 new cars in 3 years, I again will not order PCCB.

russo

The cost of the PCCB's is way too much; however, for a street car I wouldn't hesitate on ordering the car with PCCB's. For track use, I would stay away from the PCCB's, its far more economical to run a good steel set up without any loss of braking power.