Due to some unforseen circumstances with my Miata that was SUPPOSED to be my AutoX car for this season.... I'm now planning on driving my 2010 Cooper S for the year. It's bone stock, right down to the factory OEM Conti SportContact 3 runflats it came one. Needless to say, at this point in time they are SHOT!

I can't justify the cost of a second set of wheels and Hoosiers, so I'm going to be running in Tire-DS PAX class. I'm looking for the widest tires I can manage to fit on the car without any rubbing or modification.

Right now I'm leaning towards Hankook RS-3s in 215/45/17, but what else is out there? Toyo R1Rs? Dunlop Star Specs? And what sizes will fit without any ill effects (speedo error, rub, etc)?

 

On a warm to hot day I would also go with the RS3.

The R1R is better on a cool day, and top dog in the wet.

The Direzza is better across the temperature range, but a tick slower than the RS3 when things warm up.

So I reckon you are on to something there sir...

Have fun, and kind regards.

Charlie

 

So is 215/45/17 my best bet? Does anyone make a 225/40/17 in anything other than R-comps?

 

I've tested 225s in both the RS3 and the R1R and determined that unless one is running at least 7.5" of rim width the 205 or 215 is better.

Street tires do not like to be pinched. DOT R doesn't mind so much and in the stock classes you find some wildly cantilevered tire/wheel combinations.

This year I'll be trying for an asymmetrical setup with 8" rims in front running 225s and 7" rims out back in a 205.

Cheers,

Charlie

 

I'm partial to the Falken Azenis RT-615k tires and they have a 215/40R17. Have used them for the past two years with excellent results. The "k" version of the tire is much better than the earlier tire. Depending upon how the club you run with organizes their meets they will do great.

http://www.vulcantire.com/tire_detai...615k_t.htm_632

With the clubs I run with we always get 15min to 30min between runs so the tires do not tend to overheat. Overheating is the only complaint I have read about these tires in Grassroots Motorsports.

Charlie, What rear bar did you go with? I am thinking about going with the H-Sport 25mm competition bar on a stock 2006 MCS with Koni Sport shocks. Rule changes now allow for either front or rear bar changes in stock classes. Unfortunately we still can not run camber plates and stay in DS.

 

I'll have to get back to you on that question - I bought it in '05 and my paperwork is home and I am in India...

Cheers,

Charlie

 

I had Falken Azenis on my WRX a decade ago, and man did those things wear out in a hurry. These will have to stand up to the rigors of daily driving as well as AutoX, so I've been a bit weary of Falken after those.

As far as time between runs, it depends a lot on the event. There have been events where I've sat 30 minutes between runs (and didn't want to because it was cold)... and events where we've been into grid and back out in less than 5 minutes, scrambling frantically to spray the tires down before we had to make another run in the 90+ degree heat.

And that brings me to another question... CAN you put any camber on the front of a 2010 Cooper S? I've heard something about pulling plastic pins out to give them a bit more adjustment, but... I've been searching and can't find any solid info.

 

The RT-615 and RT-615k are far superior to the older Azenis. On my first set I did three years of auto-x events (approx 50 days) and six days at HPDE events. I only used them on the weekends including travel to and from the events. Rotated after each auto-x event and in between morning and afternoon sessions at the HPDE events. They were fantastic right to the end. I was competitive with my friend who replaced his annually but drove on them daily.

Now I am on the RT-615k tires and they are much stickier than the older ones and still seem to show good wear characteristics. They have two full auto-x seasons (approx. 30 events) but no HPDE events. I think that I will be able to get this year out of them. Definitely softer and stickier than the RT-615 with slightly faster wear.

My understanding of the R56 is that there is a metal or plastic plug/pin on the top of the strut tower that can be removed/punched out that then allows the top of the strut to be slide inward to increase the negative camber by about .5 degrees. This comes from a nationally ranked HS driver. Also, there is an eccentric bolt in the lower, outboard end, of the rear control arms that will allow removal of some of the negative camber in the rear. This will also allow the rear to rotate more freely.

 

Hrmmm... there's a test & tune coming up this weekend, and I'll be there if I can get my new tires ordered and mounted in time. Last year's HS national champion James Feinberg sometimes runs with that club, so I might see if I can corner him and get some advice on it.

Thanks!

 

So as an update to this, I went with 215/45/17 Dunlop Star Specs. I did an AutoX last weekend and won tire class with the alignment still stock, and it's already chewing up the shoulders. So I managed to corner Feinberg and Gwen and asked about the alignment thing. They showed me the trick with the pegs which I did last night, and I have ANOTHER AutoX tomorrow... so.... we'll see if a bit of camber helps out even more

 

It should.

Something else you might try...

I run -2.5 out front, and -1.0 on the rears. Even so I find that to get the car to rotate as much as I prefer I run some pretty steep pressures out back. My normal setup is 38 psi front, and 48 psi out back.

If that's too tail-happy I just pull a few pounds of air from the rear to calm things down.

YMMV of course...

Cheers,

Charlie

 

How do you get that much camber in the front? Remember I'm in a stock class, so I can't do crash bolts or camber plates or any other manner of goofy stuff. I'm stuck with the limits of the stock suspension geometry.

And I run about the same tire pressures. Usually I aim for about 35 up front and 45 in the rear.

 

I am running STX.

Nothing stock about it - even the cup holder is history...

Cheers,

Charlie

Here's the car on street tires (Direzza to be exact)


And here it is back in 2005 when I was banished to ASP, this time running Hoosiers...

 

Stock class, for 2012, allows the changing of either the front or rear anti-sway bar. You could go to a larger rear bar.

But that would be a totally new thread.

 

Here is a compendium of information that looks helpful.

I reckon Andy Hollis knows what he's talking about...

Cheers,

Charlie

https://www.facebook.com/notes/hollis-racing/street-touring-and-track-day-tire-faq-utqg-140/245008598916447

 

I was talking to Jim Feinberg about that. When he started talking about "hours" for an install, I got a little nervous. I've swapped front swaybars on my friend's Miata and yanked the back entirely off in a matter of about 20 minutes, and that includes getting the car up in the air. I looked at the MINI's suspension setup, then watched a video about how to install the bar, and they basically lost me at "drop the rear subframe". The car handles well enough as-is.... I think I'm going to leave it here where it's happy in tire class.

Ahhhh. Well, the little bit of camber I was able to put into the car made WORLDS of difference. I went to an AutoX put on by the Clemson Sports Car Club, and while admittedly most of the "tough" competition in town was away at the Dixie National Tour, I still managed to put up 4th best raw time... win my class... and "out-PAX" one of the really good drivers I usually compete against, had we been using SCCA rules/classes. As best I can tell, I would have been Fastest Time PAX which is impressive for using street tires in a PAX class designed for Hoosiers! :D Between good tires and a little bit of camber on the car, it feels so much easier to drive and so much more confidence inspiring.

This was my best run of the day: http://youtu.be/OvyQGxCxpdk


Thanks for the advice, guys (and girls?)

 

FWIW, I put my rear swaybar on in maybe two and a half hours, and I'm slow. It was pretty easy. Take the endlinks off (2 nuts), old mounts (4 bolts) , pull the rear struts (3 bolts a piece), and drop 4 subframe bolts. You don't really "drop" the rear subframe, just pry on it a touch to make enough space to get the old bar out, and then snug it back up once you work the new one in.

The hardest part was getting the car up on jackstands so that I was comfortable getting under there. That was probably 1/3 of the total time.

 

I haven't figured out the easiest way to get the car onto jackstands yet, either.

I'm actually learning to drive around the understeer with trail braking and mid-corner throttle modulation. A short jab on the gas and lift will upset the rear end and help it turn a bit more. This was my best run... good enough for a Tire class win and 16th overall PAX: http://www.youtube.com/watch?v=zvI_McCYTDo

 

One of our local lots is a weirdly slick for concrete, and the shape / size of it makes courses low speed to boot. Even with the rear Konis at full stiff, sky high rear pressure, and even a little rear toe-out (I do not recommend this, the car was nervous on the freeway) I still couldn't get the car to turn the way I like. I won't be satisfied until I can get lift throttle over on that lot - then I'll back it off a notch.

By the way, that helmet cam is neat. Nice run!

 

I ended up with the 215/40/17 RS3s on 17x7 Kosei K-1 TS wheels. The 225/40/17 RS3s were not available at the time I ordered. I do not think I would recommend them anyway as the 215 RS3s are the perfect fit for the 17x7 wheels on the Mini - No rubbing at all, and good stability on the rim.

I learned my lesson last year when I put 255 width Star Specs on 17x8 wheels on my street tire stock class Evolution IX. Wider is not always faster. Street tires that are too wide feel mushy, are not as predictable, and do not inspire confidence.