Autocross Tires

[sperry]

Originally Posted by ArthurS

There is a Tirerack in Sparks? So I could order and just pick them up with no shipping?

Yep, it's just across the street from Summit:

http://www.tirerack.com/about/renomap.htm

[dknv]

Originally Posted by sperry

So, can you run R-compounds in STX? My car's no longer stock... muhahah! Is the NDS and DS division a National thing or just local to Reno, I've never heard of NDS, and I always thought "Stock" meant street tires with a 220 wear rating.

One more thing: how do you like the V700s on a 16" rim? Hows the sidewall flex?

I don't know enough about STX, but here's a link which indicates your treadwear has to be 140+ for STX, therefore the kuhmos will not be acceptable:
http://www.subrew.com/stx_subie.html

DStock is national, N-anything is not (some regions like Reno have a street tire class to get more people interested in autox without large investment in racetires).

Stock is like you just got the car off the factory floor, very few mods allowed:
http://www.subrew.com/ds_subie.html

On the V700's I had a lot of sidewall flex, but I figured it was because I was running the pressures around 37/33. The lower pressures helped my traction around tight turns - though I've heard varying theories about pressures & turning etc etc, so I was in experimentation all summer.

[sperry]

Thanks for the links, those are some pretty good summaries! Now I have to decide about staying in ESP, or taking off some stuff and running STX. I'm sure I'd be much more competative in STX... but I'll have to drop my boost controller and the ALK... (well, I gotta drop the ALK in either case).

I also need to find a way to afford some rims, tires and coilovers... lol, this damn hobby costs too much!

[dknv]

Originally Posted by ArthurS

So if I raced with street tires, I would go up against all other cars with street tires, but if i race with some tires like the ones you mentioned, who would I go up against then? only wrx's?

For purposes of points within a class, yes, all street tire drivers are together in one class labeled 'Street Tire'. However, within this class, each sub-class (i.e. A-stock, B-stock, etc.) has a different PAX factor. Therefore, if you ran a course in 1:00 min., and your PAX factor is .798, but a street tire Miata ran the course faster at 0:59, but has a PAX factor of .812 because their car is sub-classed differently you'd have the lower time of the two.

If you raced with performance tires and went into a non-street tire class - you'd be up against other cars that the SCCA has deemed similar to yours. For example, D-stock also has the Integra type R, Mini S, Audi TT and a few others. (Early in 2002, we had an Integra driver who killed the WRX's times but then he dropped out 1/2 through the season.)

Hope that helps.

[ArthurS]

helps. I still am a little confused on some issues, but once I go for the first time, they will all be answered. what class would I go in if I kept the stock rims and times?

[ArthurS]

well time for me to be a n00b again. I plan on getting 17" by the end of the month. I will be getting either Prodrive p7's or Rota SDR's both in silver. I have looked around at the rims for awhile, and these two seem to stick out in my mind as good-lookin rims. I am sure the SDR's will be better for the autox since they are lighter and wider. but i may just stick with the stock stuff for my first autox season.

So now at the end of the month Ill have some rims, but no tires. Thats the question. what are good high-performance tires that will last awhile but don't cost 250$ each. Mind you the p7's ar 17x7 and the sdr's are 17x7.5. Thanks for any and all input.

[sperry]

I dig those SDRs.... they're sweet looking!

As far as tires, Austin and I are running Kuhmo Ecsta Supra 712's (like $100 each at Tirerack IIRC). They're not gonna stick like some Bridgestone S03's or Firehawks, but for the cost, they're a really decent tire. I've had mine on my Rotas for like 15k miles, and they've been great.

[ArthurS]

thanks for the tips. suby_dude over nasioc will give them to me for 650.00$ shipped with locking lugnuts. For a extra 100$ he will included the Tanabe GF210 Sport Springs. I am probably going to go ahead and go this route, so I can get the spring cheap and lugnuts.

[ArthurS]

Thanks. I looked over tirerack and saw 2 different types through Kumho. These are the 2:

215/45YR17 Kumho Ecsta MX In Stock $117.00 $468.00

215/45WR17 Kumho ECSTA Supra 712 In Stock $87.00 $348.00

Should I spend the extra 30$ per wheel? Also, someone told me that 215-45-17's for a wagon and 225-45-17's for sedans. Is this true? Thanks again for the help.

[sperry]

Originally Posted by ArthurS

Thanks. I looked over tirerack and saw 2 different types through Kumho. These are the 2:

215/45YR17 Kumho Ecsta MX In Stock $117.00 $468.00

215/45WR17 Kumho ECSTA Supra 712 In Stock $87.00 $348.00

Should I spend the extra 30$ per wheel? Also, someone told me that 215-45-17's for a wagon and 225-45-17's for sedans. Is this true? Thanks again for the help.

The MX line is brand new for this year, so I don't know how good they'll be. They're prolly pretty good since a lot of people are considering them for STX class autocross tires. However, that might mean they'll be too soft for long time street use, and you'll find yourself replacing them every year... so I don't really know.

I'm really pleased with my 712's... for the price they've got a lot of performance, a lot of tread-life, and are pretty quiet, even in a wider 225 size. Perhaps all that's true of the MXs too, with even more performance... if so, I'll prolly get some for my next set of tires... but I'm waiting for some reviews 1st. You should get 'em and let me know...

Since the wagon doesn't have the flared fenders like the sedan, it's a little harder to cram the wider rubber in there. IIRC Kuhmos are actually pretty narrow compared to the contact patch width, which is good. I'm pretty sure 225 Kuhmo's will fit on a wagon w/ stock suspension... but if you're going to hook up the lowering springs, I'm not sure what that does. You should ask around the NASIOC suspension forum... I'm sure there's someone one there that'll know first-hand about 225 Kuhmos, SDRs and springs.

[AtomicLabMonkey]

I went out to the SFR regional auto-x at Oakland Colliseum for the first time yesterday and watched for a while, there are some SICK cars there. There were even 4 or 5 guys that had 95 Mustangs like mine, which is somewhat rare. One guy had a nice cage/racing seat in his GT which he let me try out and made me *really* want a better seat in my car. A whole bunch of prepared class cars, C-Prep mustangs/camaros, even an A-Prep BMW M3 E36 chassis which was just nutty. Quite a few Subarus, some of which cornered very flat and were real fast on the course. There's some *money* at these bay area events man, jeez.

[sperry]

Anyone else notice that Tirerack is now recommending all Kuhmo ESCTA V700's be shaved for dry applications!?

http://www.tirerack.com/tires/tires....del=Ecsta+V700

Notice:

The ECSTA V700 must be shaved to 3/32" - 4/32" tread depth for any autocross or track use in the dry.

Kumho advises that the ECSTA V700 DOT-legal competition radial must be shaved prior to use in dry conditions. If this tire is not shaved, excessive wear may occur causing the tire to wear to the cords prematurely in a localized area.

Tire heat cycling will not prevent the excessive localized wear of full tread depth tires but will continue to enhance the tire consistency and wear on shaved tires.

The ECSTA V700 should only be used at full tread depth (6/32") for wet track and wet autocross use.

I'm thinking of running the Victoracers V700's instead... they seem to last a bit longer, and don't need to be shaved!

[Kostamojen]

Originally Posted by ArthurS

Thanks. I looked over tirerack and saw 2 different types through Kumho. These are the 2:

215/45YR17 Kumho Ecsta MX In Stock $117.00 $468.00

215/45WR17 Kumho ECSTA Supra 712 In Stock $87.00 $348.00

Should I spend the extra 30$ per wheel? Also, someone told me that 215-45-17's for a wagon and 225-45-17's for sedans. Is this true? Thanks again for the help.

I just went from 712's to MX's and the difference is HUGE, night and day. The MX's work just as well in the rain surprisingly, but I think they will wear a tad faster. The MX's ultimate grip level is far higher, and the only other comparible street tire is the Falken Azenis which isnt very good in the rain.