good autox tire setup
 

So I *may* be able to buy a set of dedicated autox wheels/tires here soon. Maybe. One thing I notice is that for a 15" wheel (8 or 9 inches wide), I can run from as skinny as a 225 to as wide as a 275 (with a few mods to the fenders), but the tire companies I'm looking at on tire rack only seem to offer 225s and 275s, with no middle ground in a 15" diameter tire. I'm looking at DOT slicks (Hoosier A6, Kumho 710, BFG R1, etc.)

So, my questions:

- Is there any good reason to run a 275 for my use versus a 225?

- Has anyone found a 235, 245, 255, or 265 width DOT slick in a 15" diameter?

What I decide for tires will ultimately impact my wheel choice, since if I find there's no reason to run a 275, then there's no need for a 15x9 wheel, I can save the cost and weight over the equivalent 15x8.

TIA

emilio talked me into the 9'sfor the track because the contact patch is better and there's more grip than with the 8.

I wouldn't want to pull fenders to get huge 275's on an NA.

Only reason to spend over 1k in tires is if you are building a SSM/CSP car to be competitive...those hoosiers are not cheap.

Or you just have the money to spend.

225 or 275 are pretty much it for 15" rims unless you are interested in 13" 255s. Be careful about running slicks, they put you into the EM and XP class where you must have an approved rollbar installed.

Hustler - Interesting. Even for 225s?

Mania - If I'm going to have dedicated tires, they're going to be grippy. I miss my 13x8 225/45 Hoosier S03 days, when I was turning faster times with an n/a car! 3 times the power with 1/3 the grip isn't as much fun.

EvoRoadster - You can run DOT slicks in SM2 in SCCA and clubs who've adopted their rulebook. Not sure what it's like on the islands but that's how it is here.

I'm running 215 wide 17" V710s and am plenty competitive in SSM (was SM2). I don't think you'd have any problems on a 225 15"

the latest GRM has a tire test on an RX8 using super wide vs. kinda wide tires. their results show better times with the narrower tires. you'll have to find the whole article to find out why since I didn't take notes when I read it.

225/45R13 Hankook Z214 FTW.

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I run 225/50/15's on the factory 6" wide wheel. My tire guys love me (not). Convential wisdom is to run a 205/50/50 in cstock but I find that the i'd rather have the grip afforded by the larger tire.

Like someone said what are you going for. Are you looking to be competitive or just to have fun. That will tell you how much to blow and what is a good combo or not. SSM can get pretty crazy in the $$$ department

y8s & Dopplesmoker - Thanks, I think that seals it. 225s it is.

budget racer - Your pics bring back memories! Like I mentioned above I used to run 225/45/13 Hoosiers and loved them (everything but their breakaway characteristics) and want to get back into a similar compound (A6). I don't really want to go back to 13s though, since the extra gearing is not something I need anymore and there is a brake upgrade in the future.

Pitlab - I want to be competitive and have fun! To me the two aren't so unrelated. Wondering at the end of the event how I'd have fared had I had better tires is getting old. I'm currently placing mid-pack in SM2 at the tight 510-club autocrosses and at yesterdays Corvette-club-style autox I don't know how I did in SM2, but I was 3 seconds behind a SC'd Elise on good tires (on a 46-second course). I wonder how much faster I'd have been if I'd had better tires...

This is how i've been. I'm running crappy tires at autox and i'm behind stock power miatas with good tires :(

I have RS2s being delivered today, hopefully that helps. I just cant do the slicks yet...need to be a better driver first.

In SSM (used to be called SM2) you need 275 to be competitive. Dont even bother if you dont have LSD and 275s. You wont hold up well against the Z06's and Elise.

You need much larger tires in auto-x than road racing because the vehicle operates in completely different ranges there - the tires have little time to heat up, and are subjected to substantial amounts of slip as the car is thrown around the ridiculous transitions that some courses have.

If you're getting 275 and have a budget like mine then just buy the cheapest 15x10 you can find (aero race and diamond make some affordable large wheels), I doubt you'll regret it.


I am not serious enough to get DOT R-compounds, so I just bought a set of 16x7 Rota RB's and threw on 215/45-16 Kumho Ecsta XS. Best investment I ever made.

http://img35.imageshack.us/img35/815...10546c45ao.jpg

The competitive guys at the autox around here seem to praise the Dunlop Direzza Star Spec's. I'm currently running 225/45/16 RS2's and they're ok, but I'm hoping that going to the direzza or similar soon will give me that extra bit of grip needed.

Michael

goodyear cantilevers

Hoosier makes a 255/40-13. That's what I'd run if I were getting serious about SM2 and didn't want to flare my car (you need to flare it to fit the 275s).

Depends...regional he might be just fine on 225's. For Nationals..275s or GTFO.

In SSM, we can run much stickier tires :D like the A6, V710 and R1.

Well the autox i go to is just a Porsche club event. No classes, just run what ya brung. I'm definitely interested in some seriously grippy tires, but they have to be able to be driven on the street when I feel like taking the car for a drive. I've heard mixed opinions on whether to get a r-comps or just stay with quality street tires. Maybe some opinions on that would help us in this situation.

Michael

aaaaaaaaahahahahhahahahahhaha

Never listen to any of the people who suggested street tires to you ever again. Autocrossing a turbocharged Miata on street tires is like running in socks on a freshly cured hardwood floor.

maybe a few less H and A sav, even GRM is suggesting that the gap is narrowing between street tires and DOT-R tires in terms of the compounds available and ultimate grip. and keep in mind the heat cycles on an autox course are less extreme than on a track.

narrowing the gap :ne: =

i say get the widest you can fit. i always here crap about this and that because of gearing. your not on an open track. You want the most possible grip at all times, and you dont have time to heat up your tires, hell you want to cool them down between runs if they get to hot.

I didnt say it was equal, i said "reduce the number of H and A in his laughter"

his h:a ratio is inversely proportionate to the heat of his meat.

on the beavis scale?

Update: I wasn't able to score quite as much financial aid as I'd hoped, I have secured $500 worth to spend on wheels and tires, so that changes my plans a bit. Now looking to use aggressive street tires and slightly wider wheels, and sell current setup to recover some costs. RS2s are pretty damn cheap right now...

So now my goals for a wheel purchase have changed. Looking to score some 6ULs or similar in a 15x8.

I found the lower gearing of the 13" v710 was awesome when I was NA. Not so much with the turbo. I had trouble keeping the tires from spinning a LOT, especially on the tighter courses. I'd take taller gearing anytime, I run out of 2nd gear a lot.

Just did 2 autoxs on my new RS2s this past weekend. Amazing grip for a street tire. 205/45/16 so if you're goin wider to 225 (like I want) then you're all set.

However, the tires and mounting/balancing alone are going to run you 500...not sure where you're getting money for wheels at that point.

Yep, I'm planning on 225-45-15 RS2s on 15x8 6ULs. I'm hoping to find some wheels used, since those will be coming out of my pocket.

I'm running 225/45/16 RS2's right now. I feel there a reasonable perfemance tire, but if your wanting the best I think there are better choices for ultimate grip.

Of course there are. The point is that RS2s are cheap(ish) and you likely wont get better for the price.

Also, RS2s totally kick ass in the rain compared to, say, azenis.

RS2 is so last year. go with RS3, Potenza RE-11, Kuhmo XS or Z1 Star Specs is you're looking for a budget street comp tire.

From a price / wear standpoint, the RS2 still has the RS3 beat. The RS2 is $25 cheaper per tire and has a higher wear rating, which I'll enjoy since these would be daily driving tires. RE-11, XS, and Z1SS don't appear to be available in the size I want.

:werd::winner:

I've gone with a set of the new Kumho XS's which cost me $388 shipped for street and autocross duty. I would like a set of 225 kook's but for the price of them I figure I would just get some r-comps and seen as I don't want to run on slicks yet, picked the best value performance 205.... the Kumho.

If I'm going to spend money on new stuff though, it wouldn't make any sense to me to go with the same width tire I currently run (205).

Some tires like the Azenis and some R-compounds are quite a bit wider than their size would indicate. Only .4" difference between the 225 RS-2/3 and the 205 Azenis.

That's actually a pretty good point...

The 225/15's aren't ideal, but I know that Jeremy Schuster ran 225/15's for years before the 275's came out and was always one of my region's fastest. Things have changed since that car competed at an auto-x though. If you plan on doing National Tours and being competitive, the 275/15's are what you'd need.

The 255/13's are just too short unless you start playing with the final drive IMHO. I've been lucky enough to drive an ASP Z06 this year and there have been a few brief moments were we've been tickling the upper range of 2nd (72-75 mph). With the general acceptance that an upshift is about .1s added to your time, have a slightly taller 2nd gear (or more revs) and the 275 is what is needed to keep up the RX7's and their 9k redline (around 73 mph on a 4.7 rear gear).

Shueind just got his 205/50 XSes mounted, maybe I can get him to measure the tread patch width.

could not be said better, lol. did this with my car and it was horrible. ended up gettting last in the class.

Did you just completely disregard aspect ratio? :)

I did an autocross on 225/50/13 A6s last year (someone else's tires). With a 6-speed, we used 3rd gear for most of the course, which redlined at like 62mph or so. With a 5-speed, you'd probably jump between 2nd and 3rd which can still be fast.

Except maybe that 225's are faster on 9's than they are on 8's. BTW, The new RS3 (when you can find them) are way faster than RS2's.

So are there in definitive answers out there, possibly in way of charts or possibly someone with experience with a wide array of these choices?
There seems to be a pretty considerable list of tires to choose from in the ultimate AutoX Street tire category. ie: Azenis, Direzza, S03, XS, RS2, RS3, etc.

I'd heard that before, I went with the 8s though. I'd like the RS3s but between my budget and the wear rating difference the RS2 was the more logical choice for a DD.

I appreciate your help the other day after I ordered too, Emilio, thanks!

w00t.

I've been gone all week in the "desert" of SoCal with no internet access, playing catchup on threads. Wheels and tires came in though, and the buyer of my Koseis was nice enough to have the wheels and tires combined so I just popped 'em on when I got home!

Pics to follow.

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http://photos-b.ak.fbcdn.net/hphotos..._1896593_n.jpg
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^^^ I, envy. How much did it all come out to??

The wheels came out great on your car!

It was about $1200 total IIRC for everything, thanks for the compliments. :)

Holy F.....:inout:

That's including shipping, applicable taxes, mounting and balancing, centering rings, etc.

Still meng .... thats 1.2 gs

And its completely worth it. You couldn't spend 1.2gs on anything else that would make as dramatic of a difference in your autox times. Pretty much any wheel/tire set is going to cost right around a thousand bucks...

No where did I say is not. I just dont have the money. I actually was thinking of buying his wheels and save for RS2s, but once again Im broke.

$1200 is pretty reasonable for an entire set of brand new wheels and tires "out-the-door" IMHO.

Especially for a badass set.
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