rob.ok tried tracking his n/a s2k a couple years ago on 275 r-comps all around and was having a really hard time getting enough heat in the tires and I think found the 255 all around to be a better setup.

 

I am not at all surprised that some huge r-comp tires could never warm up enough.

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In view of my car; turbo with 400 whp this idea changes as my rear tires are in much higher demand than a 200whp s2000. What do you think?A forced induction S2000 would most likely benefit from more meat in the rear but you'd need to adjust how you drive the car. With the extra hp you would deviate more from the geometric line through a corner and apex later so you can get on the throttle earlier and benefit from the extra torque. If you're fighting power-on understeer you can sometimes compensate by apexing later so you have less steering to worry about as you're powering out of the corner. A low power Miata will normally benefit from driving the geometric line (not early or late apex) to conserve momentum, but a poor handling muscle car will benefit from a very late apex to take advantage of its near straight line performance.

So, you are saying that you would still stay square and tune out the front grip deviation? I think the biggest i could go up front would be a 255 or maybe a 265 max.I But lets assume i did run a 255 square set-up. I would need a significant front sway bar, yes? or would your recommend running a 265 or 275 out back to help and still run a whiteline or saner bar up front and a stock rear?

 

I don't know, but it wouldn't surprise me if it were north of 275. If fitment and rubbing weren't an issue I would have tried the big meats at all four corners.
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Didn't Krazik run 18x10 with 285's all around at one point?

 

the question is not 285's so much as the tire compound and or type... ie a 285 donlunp star spec and a 285 r compound hoosier i two wildly different tires concerning heat!

 

Yeah, He ran an 18x10 square setup on his last car, which was turbo and pushing north of 400whp. And yes, they were r-compounds and possibly full slicks. If I recall correctly, he was putting down laptimes under 1:33 at Laguna Seca.


All i know is that my stock S2K (camber joints with "track-day" alignment) with 225/255 understeers in low speed corners/turns, but at higher speeds, it's a bit skittish and has more oversteer tendencies (a wing would be nice). I've run the car at an auto-cross with a 255/255 square setup and really liked it, but without a wing or at least coilovers, there's no way I would want to run a square setup at some of the faster tracks - autoX = cool, track day = no. So, a square setup with a wing would be ideal - good low speed rotation, and high speed stability through the use of aero.

 

Yeah, He ran an 18x10 square setup on his last car, which was turbo and pushing north of 400whp. And yes, they were r-compounds and possibly full slicks. If I recall correctly, he was putting down laptimes under 1:33 at Laguna Seca.


All i know is that my stock S2K (camber joints with "track-day" alignment) with 225/255 understeers in low speed corners/turns, but at higher speeds, it's a bit skittish and has more oversteer tendencies (a wing would be nice). I've run the car at an auto-cross with a 255/255 square setup and really liked it, but without a wing or at least coilovers, there's no way I would want to run a square setup at some of the faster tracks - autoX = cool, track day = no. So, a square setup with a wing would be ideal - good low speed rotation, and high speed stability through the use of aero.
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The OP did say "no rules" just best possible set up with no fender limitations. Yes, Krazik had a crazy car, but my point is that he did run a massive amount of tire (square) effectively.

 

As robrob stated, there is a fine balance between having enough tire and having too much tire. 265 star specs are readily available, and star specs are competitive tires. Yet, nobody uses them. They've been tried, and for the most part, ruled out as being faster.

For another data point, the Japanese NA time attack s2ks all don't run huge tires. The turbo ones do, but they do have (a crapload) more power.

 

But lets look back at the original question.... This is a question of correct amount of tire(grip) vs too much tire (heavy). The argument was that a square set-up was reached in-part due to rules and in-part due to nonavailability of tire sizes above 255 in 17's(with exception of course). Do we all agree that that different ends of the car require different size tires? What I am trying to get out of you guys is that it is a matter of function; use a square set-up and tune out the too much front grip in relation to the rear due to the above constraints or run a correct staggered set-up. Does this sound right?

If so and there were no rules and you were after your "perfect" set-up (and you were in my boots with about 400whp) would you stagger your tires to control the extra power?

 

Another reason is that rims wider than 17x9 that fit the s2k are not readily available, even now.

 

I hate to burst your bubble man, but you will probably never get us to all agree to that. Here is another thread (its only a page back) with some more explanations to throw in. https://www.s2ki.com/s2000/topic/933...#entry21487264