Seth Thomas

What track and who were the drivers?

Jbravo23

Has anyone even seen these tires? I’ve yet to find a photo on the internet. It’s always a photo of the RS 21” size.

JCR-Porsche

JC

Jbravo23

sweet! My next tire for sure.

FCMD

I wanna go the other route-I just wish they'd make cup 2s in 315/35/20 so I could put them on my 812 and not have to go to 21" aftermarket rims.

JCR-Porsche

335/30/20 is available, might be close to rolling radius required for the front?

AMG BS rear tyre

JC

RennOracle

It's definitely not marketing, that on itself is quite a naive statement to make given how expensive tires are to develop and manufacturers regardless of production they all spend the money on developing a tire for their cars.
That aside, a big part of development is to complement and tuning on "feel" the safety part is mostly on load per tire (from g forces the car can produce, roll levels, downforce values, to the individual corner weight).
The pista rears for sure surpass the gt3 values, ferraris have a bit more roll, they are heavier on the rear, so at least the sidewalls will be strong and the rears will perform well, I would take a bit of extra attention to tire pressures at least, might need a bit lower than pista values.
The problem might be with the front ones, the Pista has the tank in the back, the gt3 in the front, it's at least 90kg (90 liters of fuel) extra load on them and pretty much direct load, under heavy braking you will get a even bigger load.

I would try, but not on a very fast track. Just strap a go pro and see how much they are flexing and play a bit with pressures.

groundhog

His information is flat out wrong, period and is thus treated with the contempt it deserves.

Tires, particularly those used for track work and used at very high speeds are not just some afterthought - manufactures work closely with tire suppliers to tune tires to specific car characteristics.

This in turn impacts on the optimal alignment for a given range of conditions. The more a tread/compound combination moves away from conventional street patterns and compounds the more important it becomes to understand this and get it right.

If you get it wrong, at best you will experience excessive wear and tear and at worst, particularly in the wet - you will find you are a passenger into a tree/wall/other vehicle.

usrodeo4

I have spun thru this thread pretty quickly, but if I understand you to be saying that that the Cup2 R tires don't come in GT3 sizes but that Ferrari does have a Cup2 R on one of its cars in the GT3 sizes...I would be very tempted to buy a set and see what I think.

FCMD

Looking at this again. The 335/30/21is the only rear with appropriate load range but is great as is the same diameter. Up front though have to go 305/30/20 for load, which is up from 275s.......but down 10mm in diameter. My stance is perfect after lowering it 1.25" all around. Getting more weight up front, more grip up front may really mess up handling. The RWS really loosens up the rear just wonderfully in the 812 over the F12. Zero understeer....hate to screw that up....the opposite of good is perfect.

Trofeos are an option but have softer sidewalls and are better suited for lighter cars.

mrhamamg

yes thats a good way to sum this thread up. i ended up getting the oem N1 spec vs the cup 2 r for ferrari

carbondan

Did anyone ever come up with a final answer here?

Can I run the Cup 2R Ferrari K1 spec on a totally stock 991.2 GT3?
Any fitment issues or other notable issues?
Anyone test it yet?

mrhamamg

didn’t test it. Still curious waiting for someone to do it

erko1905

I ran one set, it was totally fine

Tire does have a very narrrow "fast" window, once you're through the good stuff it's as slow as any worn Cup2

JCR-Porsche

We ran it on our Speedster quite some time ago, worked absolutely great. No issues, no fitment issues either

Onboard here from our Speedster around Donington Park GP Circuit. Significantly faster than a stock 991.2 GT3 RS on a Cup2R


JC