Jason Saini

As for hosting, over6racing can host - but I think you can simply upload your own vids to www.gofastvideos.com which is owned by the owners of this site. If not, email me and I will host them.

I've got some good (but not as good as Steve's) vids from Peru that I need to post as well!

Windscreen

I think Rylan is kept busy with other stuff, as my Nat's videos from last fall are still in the upload folder on gofastvideo.com, waiting to be posted. I'll e-mail you privately.

...thinking out loud, "do I drive my car this weekend, or F125?"

Steve

RandyP

Having driven on the Kumho's for only the second event on concrete, I suspect that the Hoosier's are faster if there are slaloms, and the Kumho's are faster if there are sweepers. Since most courses have some of both, it may be a toss-up. I do prefer the knife-like response of the Hoosier's as they boost the driver's confidence. With 225/265 Kumho's, I had mild understeer and driver induced inside wheelspin with a very stiff front bar.

PedalFaster

Thread hijack!

I don't know if anyone read the latest issue of Grassroots Motorsports, but they tested a bunch of different R-compound tires and found the V710 about 1% (~0.4 s on a 40 s course) faster than the A3S05. This was on a CS Miata (e.g. not a tire-smoking torque monster) on the Tire Rack's asphalt test surface.

krazik

yeah I've been really busy.

Anyone want to help be a GFV webmaster and help post vids? Its all pretty straight forward.

PM me

-Ry

RandyP

You should know this is a useless data point. We need data on concrete, with tire sizes that fit the S2000.

PedalFaster

Please forgive me for not knowing better, oh master of autocross.

RandyP

Yes, I always listen to the Porsche driver who heard that tire x was fast on a Mazda when I'm trying to make my Honda faster

PedalFaster

Believe the S2000 uses tires in some magical way totally different from any other car if that's your prerogative...

Windscreen

Come on, guys, enough with the personal attacks. It doesn't do your credibility any good to take it to that level, whether starting it or responding to it.


As for tires, different cars do indeed use tires differently. Different cars have different camber curves that create different amounts of camber thrust, they have different roll rates, different front-rear roll couple balance, different roll steer and bumpsteer, different weight distribution, different pitch rates, etc, etc. that all affect how a particular tire works. That is before you even consider differences in driving styles.

Depending, of course, on the preparation level allowed, you may be able to better optimize a car for a given tire's characteristic over another's. In stock class, where we are much more limited in our ability to match chassis set-up to tire characteristics, the fundamental "nature" of a particular chassis may dictate which tire the car will be faster on, regardless of which knobs you turn and how much.

There is also a course dependency effect on testing results. Regardless of how balanced you think a test course is, you will inevitably find competition courses that have a different mix of elements that could, in fact, make your second choice tire the faster tire on a particular day.

That said, I've done some pretty extensive set-up and tire testing on the concrete of Peru, which is the closest thing we have in the mid-west to Forbes's surface (2 days of solid running). On the particular test course I was running, I found the V710 to give approx equal times to the S04, and the S05 to be about 0.5 sec faster (V710 was 225/50 all around, S04 is 225/245, and S05 is 245 all around).

Try a different course and things may shift a bit. My seat of the pants tells me that the V710 has a bit more lateral grip and gets power down a bit better on asphalt, but I've not done any proper testing to confirm it. My focus is the national championships at Forbes, so I've not been too concerned about asphalt. In fact, I'm quite certain that my shock valving is too much for asphalt, especially if it rains. I can't get my car soft enough for wet asphalt.

So, in my estimation, the tires are very close on the S2000, and with subtle changes in course balance, different tires may come out on top. I've found the S05 to be faster in the ranges of my general set-up on concrete, and I find the feel to be more confidence inspiring. Things may well be different next year on asphalt, but I wouldn't be surprized if Hoosier comes out with a tire that works better on asphalt.

Steve