imstimpy

I am interested in increasing grip beyond the standard 255mm 200TW tires on a 9" wheel. My thought was to increase wheel width and get into a 265-275 200TW tire. Others have suggested sticking to a 9" wheel and going to Hoosiers instead to keep suspension stress and fatigue low.

• Is there a point of diminishing return on wheel and tire width on an S2000 with a stock longblock? The BSP autocross guys have found success going with 295+ on 11" wheels, but they don't deal with 70+MPH corner loading, 100+MPH straights, and curbing.
• Is there a theoretical wheel/tire width limit that, once surpassed, begins to compromise the suspension and hubs beyond the common 255 on 9"?

Thanks!

s2000Junky

Not within what the stock modified fenders can accommodate in my experience. Ive been running a 255/295 stagger for quite a lot of miles now 100k?, and knock on wood am still on the factory hubs/bearings with about 220k miles now. This is with some hard track time as well on a big 2.5 mile course, not auto X. But this is on a track/street car where I'm trying to get the most grip possible wile running an extreme summer 200 compound. This winter I have moved up to a 275/315 stagger on widened rpf1 17's still the stock body/no over fenders. Not only are these light wheels even at their extended widths, but the offset is still centered over the hub/bearings at 10 +55 and 11.5 +63. I am running a standard powered bolt on/tuned F22. I'm looking forward to further improvement in track times. The rear 315/35/17 NT05 tire I'm running this year with wheel weighs a hair under 50lb just fyi. The previous 295 was almost 2lb lighter. I think the factory ap2 rear package weighs 46-47lb? So not much more weight for a hell of a lot more width.

Arro

a 255 tire on a 10" wide wheel has yeilded faster laptimes. I think it's a combination of improved contact patch and better (crisper) feedback from the slight stretch of the tire on the wheel. I believe a quick forum search would produce a couple links. IIRC, there was one lengthy thread about 9" vs 10" wide wheels. If you know AC, he recently switched to the 10" wide wheels and liked the change.

s2000Junky

That's true, mating the proper width rim to same tire section width is best, but this wasn't the question.

s2000ellier

a 225 a7 is gonna have more grip than your 275 200TW

thomsbrain

Assuming you're willing to run whatever fenders necessary and have the correct offsets, I see a few options for max width on track days:

295/30/18 Trofeo R on 11" square
295/30/18 Pilot Sport Cup 2 on 11" square
295/30 front and 335/30/18 rear Hoosier R7 on 11" front and 12-13" rear (rear getting tall)
285/30 front and 335/30 rear BFG R1S on 11" front and 12"-13" rear (rear getting tall)

Back to 200 TW:
285/30/18 RE71R on 10.5" square
275/35 front and 315/30/18 rear Rival S on 11" front and 11.5" rear (getting pretty tall and might foul the headlight)

For the front, you're probably looking at either the J's fenders or Circuit Garage overfenders, or the ASM/J's widebody kits. Might be able to use the Downforce fenders combined with the Evasive overfenders. You'll also need custom wheels from CCW or Forgestar (not sure I'd trust Forgestar with this level of grip). The BSP guys used stock fenders and high-offset CCWs but they pulled the crap out of the the fenders, ran high ride heights, probably couldn't use all their steering lock, and used insane amounts of spring rate and sway bar, so they probably never tucked the tires under the fenders. And once you've added wider front fenders, you'll probably find yourself wanting rear overfenders, too. If you give a mouse a cookie...

We're probably talking $6000 for tires, appropriate wheels, and bodywork/paint, unless you can score appropriate used wheels and/or do the bodywork yourself.

Mrsideways

Ran 275/35 17 A7's on stock fenders on 17x10's. It fit other then the left front the inside edge of the tire rubbed on the frame inside pretty good.

Tougefactory

275s can fit for sure on a 10 inch wheel

gtracer

Then you start to get heavier wheels and tires. I believe its a balance of weight / grip. Recall rolling resistance and aerodynamics. The wider, the worse, so yes, depending on your power, there would be a point of diminishing return. Along with rotational mass...

A 245 Hoosier will stick more than a 275 setup and will be much lighter. Heck, a 275 Hoosier would be lighter than a 200TW tire...Keep it in mind, if you do switch to hoosier... you're screwed, you'll be hooked.

I think the suspension stress issue would be so minimal that tracking your car alone would deterioate that argument. Besides, I am sure a 255 Hoosier would put more stress on components than a 275 200TW tire..

I have a hard time justifying a 315 width tire on a 230-240whp tops(?) N/A S2k...

Its still a lot more weight than needed. You could run a 275 Hoosier on a 10'' wheel and it would be under 40lbs...

imstimpy

My question is not "can I run a 275+ tire and what does it take to do so?". My question is "if I ran a 275+ tire, is it 'better' than a 245 r-tire or less reliable?". "Better" being faster, obviously, but also without dramatically affecting reliability. Being faster takes into account rotational mass, rolling resistance and aerodynamics, and unsprung weight.

Can a 275+ fit under the car? Sure, with the right amount of time and money. Is it faster than a 245, though, and will it break proportionally more? That is what I am after. I understand this is also an "it depends" question. For a little track like Driveway Austin or Harris Hill Road, a wider tire would likely be faster given the low straight speeds. On a track like Texas World Speedway or Circuit of the Americas, pushing a 315 for 2/3 mile at 100+MPH with 240whp would probably hurt. In fact, I think I noticed an effect on end of straight speeds just going from a Hankook RS-3 to a Bridgestone RE-71R.

I'm fairly confident going from 9" to 10" on a 255 200TW would be faster. I'm skeptical it would be faster than a 245 Hoosier or even a 225 Hoosier. Cheaper in the long run, maybe. From what I'm seeing a 295+ 200 TW might be necessary to keep up with a 245 Hoosier and at that point I'd say an 18x11 200 TW setup is not worth the investment.

Thanks for the discussion so far.