redspencer

iTrader: (1)

Mike,

Do you find it more beneficial to run a 265 square setup instead of using a slightly staggered setup such as 265F/285R to have a little more available meat on the rear tires (especially when you're utilizing a clutch differential)?

FIGS

iTrader: (11)

I would say I favor a square setup on track because it makes the traction limit more predictable and relative tire temps the same plus weight vs traction of the wider wheel setup has better dig characteristics on throttle. I actually still miss the 245 (r-comp) and still not convinced the weird shape of the R888 and its transition behavior. The OS Giken will push right through the apex with grip under acceleration so I never need to worrry about the back end swapping up. Even when the rear end does step, its extremely settled and easy to get back in line thanks to the changes we have made. Larger tires slow everything down and the skinnier the tire and lighter the wheel, the better the F handles as we have it setup. If I go wider I find there is not enough power to take advantage of it, at least with the tires we have tested. The 305 street tires we could get to break loose, just not the stickies so I think it really depends on the tire, the air pressure etc. Add on top of that the amount of bumpsteer and camber run in the rear and there are too many variables to make a generalization. When dialed in our car has so much grip that you start to weigh the consequences of losing it and usually I would rather take home the car in one-piece than "win " a track day.

redspencer

iTrader: (1)

Thanks for the detailed explanation and perspective!

Your reply definitely has me contemplating on future tire set-ups and whether or not the added weight of larger tires is worth the additional traction (in my case, I'm looking to go from 245F/265R to 255F/275R on Michelin PSS tires).

SubOrbital

He is talking about a much stickier compound though.