bmw_e30

i run cup2 k2's on my 991.2 gt3 they came with the car so they're my baseline moving forward

JCviggen

I have a set of SF90 K1 cup 2r ready to try soon... 255/35 and 315/30. They were only $300 more than a set of regular cup2 n1 and $700 less than Pirelli trofeos so worth a try I guess.

Cay_PI

I run the 255/315 K's as well on a 991.1 GT3. Works fine. But rear is not wider at all, front only 7mm.

JCviggen

Yeah the Porsche 305 is a 320, my concern even with a 315 is not stretching the tire. I ran a 315 Trofeo R and it was OK but technically not rated for a 12" rim. The SF90 has 11.5 rears as well.

JCviggen

Confirm that the 255/315 K1 Cup 2R setup works really well, with one small asterisk. I ran mine on the Nordschleife and under the biggest compressions (150 mph into a huge dip) the fronts rubbed, I even smelled the burned rubber a second after. No obvious marks on the tires though. On normal tracks you wouldn't have an issue. Grip is outstanding but had to get used to how direct the front axle was at high speeds, could hardly put any steering on compared to the Trofeos.


Rubs at 10 seconds and 2:04 but I had already scaled back my ambition a little in these spots.

I ordered a new set but with the even cheaper 245 K1 tire off the 488 Pista. Those tires are only like $320 a piece but will see how they work. Probably older manufacturing date.

srwhitman

Tire rack now sells the N spec Cup2R. https://www.tirerack.com/tires/tires...tandard+Brakes

I had tried the K spec before. A lot pricier actually - these are reasonable.

However, I personally hate them - K or N - take your pick. Why? Well both times the car felt like it was skating. I've run the Trofeo R's many times and they are just fine - in fact, its my favorite tire. the price now for the Cup2R (depending on the day) is very close to the Trofeo R so I figured I'd try again but never again. I guess maybe they work for some people on a track but they didn't for me. I took them to a very well maintained track and they just were awful from the beginning. I would feel like I was running on a gravely road. It would slide and stick - but not with any kind of predictability. It would pick up klag (tire marbles) or little stones. The straights were fine but who cares about that - its the turns. I was looking for confidence and I got quite the opposite. I have always felt like the Cup2 never quite gave me the grip I was looking for and I wish the Goodyear Supercar 3R came in the size for the front on the GT3 (I have a 991.2). I've run Dunlops, MPSC2, Goodyear 3R in rear with Supersport R in front, Trofeo R's and now the MSPC2R. I think the top 2 are the Goodyear combo and the Trofeo R's with a slight nod going to the Goodyears since performance is very good and they are cheaper.

JCviggen

Weird experience. I've run 3 sets of Trofeo R this year and 2 sets of Cup 2R and the latter are clearly faster but a bit different to drive. More direct, less steering angle at speed but in the low speed they need more than the Pirellis somehow or other. Under braking the Pirelli can't touch the 2R but it's not too far off in the high speed.

Here in EU my last set of Ferrari spec Cup 2R was the 245 off the 488 Pista and the 315 off the SF90 and the set cost me less than $1500 vs $2300 for the Pirellis. And I set the Nurburgring lap record on them...
N spec Michelins were a lot more expensive still. Unfortunately there's been a price increase on the SF90 rear tire so it's now closer to $1800 but still well cheaper than the Pirellis and N specs. I do like the Trofeo but it wears the shoulder down really quickly and then the performance drops off a lot. The 2R so far is wearing very nice and even but not finished either set yet.