Slantnose!

Hello, just checking-in to see if anyone has experimented with wider wheels or tires yet on a C2S?

MerlinsGarage

If you have the 295's on the rear, the 305's are an easy choice since they come on the C4S as standard equipment.

kosmo

yup, Porsches also offers 1/2 wider wheels w/ 305s out back.
what are you trying to achieve ?

SM_ATL

Running Yoko AD08R 255/35-19 for the front, 305/30-19 for the rear for the first time this week end. I thought I might as well go a bit wider (than narrower @ 235 with my R88 set) this time and see if I feel a difference in turn in or grip -knowing that the compound is less sticky of course-. I'll report when I am back from the track.

lunarx

255/F, 305/R.
Front is planted.
Rear is loose.
I think reducing rear camber and increasing rear toe will get the rear to work better.
Alignment pending.

Mport68

I'm considering the AD08R in 255/30R19 for the front of my C2S. I have the optional 8.5 width wheel so the tire should fit ok, just not sure of the strut tower clearance. SCCA street class allows a 5mm max wheel spacer so I can't shim the wheel out much over stock off set.

Anyone fit this tire yet?

lunarx

I dont see why it would not fit.
I have a 9x20 wheel w/ 51mm offset and a 255 clears easily.
The 255 was barely wider in section width than the 245 so it wont change your clearance by much at all.
You will get more tread width though, but that does not affect strut clearance.

Mport68

Thanks Lunarx... I'm going from a 235/35-19 Sport Cup with a 9.5" section width to the 255/30-19 AD08R with a 10.1" section width. I've looked at & felt the gap and believe that it will fit, but I was hoping someone that had fit a 255 on a near stock off-set wheel would chime in. But your example tends to confirm that it will fit.

LexVan

Correct. This is the Sport Techno wheel set-up.

MerlinsGarage

A little loose is preferred, but if you have too much oversteer increase rear camber (neg) 1/2 deg at a time and decrease toe out. Make one change at a time and always be sure to check surface tire temperature and pressures after each change.

Quest911

maybe trying to roll hot asphalt for the paving crews fixing potholes everywhere

maximmm

Waiting for results. Try Michelin cup 2.

lunarx

Something to keep in mind is that the AD08R will have 0.2" less section width on an 8.5" wheel vs a 9' wheel.

Therefore your section width comparison will be:
9.5 [235 Cup]
vs
9.9 [255 AD08R]

So your Strut clearance will only be 0.2" less (1/2 the section width difference).
If you can get a finger, between the tire and strut now, you should be fine.

lunarx

Do you ever think that reducing rear camber could help increase grip?
It seemed like my rear tires were not using much of the outside edge.
With PSS, you have that bi-compound tread, so grip is not as good on the inside, where they use the harder compound.
I'm thinking I would get more grip by getting the tire to use more of the softer outside compound.

I don't know what the settings are at the moment, but I worry that increasing camber might make it more loose, which I know is against normal logic.
Also, considering the larger tires, extra camber will reduce outside contact even further.

Is there such a thing as too much rear camber?

paradocs98

Looking forward to your findings. This is my exact setup.