quadslo

I am trying to find correct tire size for my Cayman S with 20" Carrera wheels.

Is 245/35R20 ok for the front? I don't see 235/35 size of Cup 2 with N rating.

What is the difference between N1 and N0? Which one do I need?


If I go for 19" set, which sizes of Cup 2 do you recommend for that?

Chris3963

Why do you want Cup2 tires on an S?

donR

The 245/35R20 will fit fine on the front. There is no 235/35 in Cup 2. The 295/30 fits on the rear 10" rim but it is really a bit wide for the rim. 265 to 285 is a better fit.

N0 is the older generation Porsche Cup 2, N1 is the newer generation Cup 2.

Get the N1 if you can unless the N0 is much cheaper. The N1 is meant to have revised compound with slightly better wet weather performance. Otherwise its probably hard to notice the difference.

I have the N1s and they are very good in the dry (much better than the 4Ss) and still work ok in the wet, although not as good as the 4Ss in the wet.

If you go 19" then ideally you want to go 19 x 8.5 and 19 x 11. This will allow you to go max 255 on the front and 295 on the rear. I know someone who has 911.1 Carrera S IV wheels which are 20 x 11.5 and he runs 305 on the back and 255 on the front.

You just need to be careful with your offsets.

MidEngineRules

In GT4 20" sizes, the N0 has zero wheel protection. The N1 does which is a plus. Still when my Cup 2s wear out, I'm going PS4S as for street temps, I truly believe it's more grippy than the Cup 2. My DD has PS4S, replacing Cup 2s of the same size, and I swear they seem just as sticky but with far better wet road holding. FWIW.

donR

I agree with the above. Good point about the N1 having wheel protection, although not sure how much it helps in reality.

You need to be working the Cup 2s and warming them up before reaping the benefits which is not really possible around the streets where the 4S is a better choice.

However, if you are carving mountain roads or autocross or track work in the dry then after the first few corners the Cup 2s warm up and are a noticeable improvement.

If its raining or damp the Cup 2s will still work once you warm them up but you can feel them wriggling around and they are just not as confidence inspiring as the 4Ss and to drive the Cup 2s fast in damp or wet winding roads you need to be very good at driving at the limit, but hit some dry patches and you can leap ahead.

Chris3963

I was chatting to a Porsche instructor co-pilot at the Nordschleife in October as we thrashed a new 992 around the circuit. It was wearing regular Dunlop road tyres. The previous day I had been out on the track in my GT3 RS on Cup2s and I remarked that it would interesting to see what the 992 could do on Cup2s. He shot me la ook and said Why? Firstly he said the suspension is not calibrated for them and secondly, and most importantly, he said, if I can do 7min 30 secs around this track on standard tyres, you don’t need Cup2s on this car. Total waste of money.

A couple of days later,I did a taxi lap in the Apex GT2 RS and asked what tyres they were running....Michelin 4S. To say the least, I was surprised considering the grip levels and speed we were hitting. Asked why 4S and he said they last much much longer and provide more than enough grip in the GT2 to still frighten people!

So in a nutshell, you don’t need Cup2s on an S.

quadslo

Thanks for the help guys.

Chris3963, thats interesting. I haven't lapped my Cayman yet, but from the experience from other cars on track (no Porsche), I decided to go with the Cup.
I will put 4S on for daily use. But I may try to go on a first track day with the 4S, before buying the cups.

Chris3963

If this is going to be your first track experience, then this just reinforces that you don’t need Cups. Unless you have some God given unnatural talent, the S on standard tires is going to have handling limits way beyond your experience. The best investment for your money to help you get to the limits of your tires and car, is to spend it on lots of lessons. And even then it will take you lots of track days to get to a level where a set of Cups might be of some benefit. Besides, an inexperienced driver can often ruin a set of Cups faster than an experienced driver.

GrantG

You cannot make conclusions about what tires are needed on a normal track based on what works at the Ring.

Driving on the Ring should be considered a different sport than driving on typical US tracks.

On my GT3 on home track, Cup2’s last fewer than 3 (half) days (and 4S’s are totally inadequate unless it’s raining).

At the Ring, I can barely wear Cups at all in a week.

#1SomeGuy

I'd imagine with the taxi they also would want a wider operating range as every day isn't perfectly warm/dry and the 4S buys you a little more confidence if the surface isn't perfect.

Chris3963

I agree with your point for a GT3 and, certainly, the ring has its own rules but we are not talking about a GT3 here but a Cayman S. If was a GT3, I would never recommend 4S tires for the track. However std tires on a Cayman S would be fine, even on my local tracks such as Spa, Zolder, Hockenheim, etc. As an example, one time at Portimao in a Turbo S on Pirelli Pzeros, I was faster than many of the GT3 RS and GT3s on Cups. It wasn't the tyres that made the difference, it was the driver.

So I think my assertion still holds that if this is his first track experience in a Cayman S, he does not need Cup tires. He should learn the car on the standard tire combination because even in that configuration it is going to be so far in advance of his skills that he should save his money.

GrantG

No argument about learning the car on standard tires - makes sense.

2XIPA

I did not know that about N1 and NO tires. Good to know. Thanks. Big fan of the PS4S too.

Buckett76

When I got my new Boxster GTS i took it to the track with the PS4S it came with and those held up really well but I have a set of 19" OZ wheels from Tire Rack with Bridgestone RE71r's on them (currently 235/265, but might look for up to 245/285 max on next set if available) that I use for regular track duty. Found this combo to be cost effective and the RE71r's are plenty sticky and only around $1.2k installed per set so makes the pain of replacing them every 4-5 track days bearable. If it's your first track day and your tires have enough tread left, just use those and see what happens. If you get addicted then get a set of PS4S for your stock wheels for daily use and buy some 19"s with the RE71's, plus then you don't have to deal with cleaning all the rubber and brake dust every time you get back from the track.

2XIPA

Exactly what I did for my Spyder. Two sets of rims and tires is pure luxury.