I have 255/35/18 rt660. 18x9 inch wheel. Been having an issue with rolling completely over the triangle near the side wall. Added more negative camber and it helped just a little bit at -3.5front and -2.0rear but still rolling over. Only thing I haven't tried which I feel pretty stupid is tire pressure since all my friends tell me they run 28-30 psi hot. But i realize all their cars are lighter.
Any of you guys run this tire size or even rt660's can give me a hot pressure to start with and test out?

 

Try 35 to 40 psi. check temps across the tread after each run and use chalk out over the side walls.

You will need to adjust your driving style too.

Details about your car and suspension will be a big help to get you better answers....

 

I shoot for 32-34psi hot
make sure your rear lsd is working for you before chasing front grip issues

 

10k/12k feals coilovers. Stock front bar 24mm rear bar on soft. ACD tune by english racing, rear diff restacked. So suspension wise i think i should have enough roll resistance.

 

You need more tire. Sidewall is too short on those. Go up to 265/35's at a minimum.

Also, 30psi hot is low. Usually need 32-34. Alignment is range, but it depends on your suspension setup too. More camber can't fix soft springs.

 

I agree with Sean. I was going to recommend more camber but I dont know the track layout. if you find yourself pushing because youre slow in-fast out then you might need to improve your approach

 

Keep increasing hot pressures until no more side wear. You may need to be anywhere between 35 to 39. I use R888Rs where Toyo says anywhere between 32 and 38 hot. I'm not sure what Falken recommends hot.

 

this - i setttled at about 35-36psi hot on rt660's in 255/35-18