Autocross newbie question....
Are there rules to what tires you can use? Tread ware rating? Slicks? If so does everyone use the same tire? If so how is that determined? Sponsors?

Goodguys autox street classes require 200tw or higher. Scca solo stuff I think only require DOT tires in street classes but I am unfamiliar with those rules. Personally I'm not to thrilled with the 200tw mandate since it limits me on choices and my rears are almost $1000 a pair for ps2's.

Yes Brad there are plenty of rules regarding tires. And it changes from club to club. The first thing you should do is find out who you would be running with the majority of the time and also other events you would like to attend. Many times your tire rules are based on the class where your classifies. For example, if you raced with the SCCA, you would be classified as c-prepared and you could run any tire you wanted with a minimum weight of 3200lb (over 5 liter) with a 50lb weight penalty for rims larger than 16" and another 50lb weight penalty for wider than 10". And you would be pontentially placed with other purpose built race cars (see John Sandberg's AAR 'cuda). If you go to a Goodguys event, it's run what ya brung but 200 treadwear rating. Carlisle is completely wide open.

As you can see lots of variables so before I could recommend you a tire you would need to figure out what rules you are adhering to.

Kind of like circle track racing, eh? Rules change per track.

Brad... you'd further want to consider having different rim sets/tires pending with whom/where/class you'd be in.. ALL PENDING how serious a contender you want to become, and.. how deep is your wallet with allowable "tire money". MAYBE... you could get a sponsorship for tires.. you'd have to be pretty dedicated to the sport and the sponsor (tire company and/or distributor).

The hi-end all-out seriously committed SCCA solo/autocross (pylon events) racers will usually go through 2-3-4 sets of tires a season.... running about 2-3-4 events per month between spring~fall.

Look at the clubs you could participate with and their "tire rules"; determine your "classification" if its any matter.

The mentioned 200 tw is becoming more popular with many clubs, in part because you could, theoretically, "drive" them to/from an event as well as every day. BUT.. choices/sizes become more restricted... and once you jump up the typical 17-18-19-20" sizes... they are increasingly expensive.

You'll notice the "GoodGuys" event's top finishers ALL have the stickiest tires at 200 tw.. which is the organization's "tire rule limt".

At SCCA Solo Street Prepared and similar categories, the softest, such as Hoosier A6, Kumho and some others with a 40tw.. stick like glue real quickly (and they harden up over time, too)... and maybe you can get 30~60 minutes of competition autocross time out of an A6 Hoosier before they need replacement again to remain competitive at a top level.

As the old saying goes: "How fast do you want to go? How much do you want to spend?"

The driver (aka "nut behind the wheel") will still make the biggest difference in the driving performance.

Starting at the outside of the car (tires/contact patch) is a critical performance decision... then moving inwards (suspension, etc).

I'm personally making decisions based upon various club's tire rules which I've chosen to participate... will probably end up with at least 2-3 sets of rims/tires accordingly... to remain "competitive".

Here's a picture of my Hoosier A6 275-45-16 autocross tire (40tw) on my 16x10 rims, and my BFG T/A street/hwy rear tire 275-60-15 (400 tw) mounted on 15x8 minilite rims (same as your's). My old Hoosiers are worn out from last year's Sept MMW/Indy autocross (took at least 30 50-second runs), so, right now I'm considering to either get another set of Hoosier A6 (or R6 for road course competition) tires, or else maybe BFG G-Force Comp-2 255-50-16s (340tw) so to simply drive to/from various road course lapping events ("The Hoosiers shouldn't be driven on the road"... ok officer.. I've been told that before!). I'm also seriously planning to eventually get a set of 18x10 rims and 200 tw tires sized at ~275-35-18 for the front and rears.. and probably drive ONLY on them to very selected events... until I start trailering again in the future.

SO.. be very selective of your choice(s)... ultimately to (1) be able to enter, per "rules/restrictions" and actually compete at the event, (2) be reasonably "competitive" against the other entrants, and (3) spending the $$$ wisely as you can afford.

(sorry... the attachment needs to be opened by the viewer)

I'm looking at this as one of the events I could literally walk to it's so close to my house. If I broke I could walk home!
http://www.casc.on.ca/autoslalom

Problem is I've been reading their darn rule book for about 1/2 an hour now and still can't find the tire rules!
Rule book is like 10x thicker than the oval track stuff I'm used to. I see they have an event coming up in a couple weeks about an hour or so from my house , maybe I'll go for a drive and check it out? That would be the best way to figure out some questions I guess?
I assume I could just get someone to look over the car and they would let me know what "class" I would need to be in? That part is confusing in the rule book too!

I'm thinking 4-5 times a year would be fun, nothing too serious? It would depend on the "type" of people that attend. I don't care to be around the "stuck up" types, just want to have fun and learn.
So far with tires the 615K's look to be my best bet? Asking around I'm told to expect about 10,000 miles from them and that's about 3 years driving for me ? ( not including racing?)Replacing tires every other season would be fine with me. Might as well use them up before they weathercheck! haha I'm still looking at other options and the plan is to save up and buy new rims and tires next spring.

Thanks everyone for the help so far!

EDITED (Brad and I must ahve been typing at the same time)

Gary and Mitch have covered it pretty well. Best thing to do is go to at least one autocross and get a feel for the club(s) the rules and how far you may get hooked. edit: Looking at the Canadian rules they adopting the SCCA rules. The next biggest sanctioning body here that runs different rule set is NASA.

You can show up with just about anything and run. The limitations on that end are mostly the judgement of the tech inspector and safety steward. (Their word wil be final.) Basicly stuff you'ld expect like no bulges and no cord showing. Studded tires are generally not welcome. Drag tires will probably depend on the specifics and the discretion of the officials. (Like I can't imagine anyone allowing wrinklewall slicks, but drag radials maybe OK).


You will also have to keep your local weather conditions in mind. The a and r comps generally dislike anything below 50 degrees F. Some are worse than others. These compounds often on have a limited number of temperature cycles they can go through before going 'off'. R comps have a hard time getting hot enough to reach their ideal operatiing temperatures. 'A' compounds are sticky almost right off the start. The tires that heat quick often need cooling help between runs. You'll see many of the guys spraying them down with a mist of water.

If you're club runs rain or shine, then either a compromise tire or a seperate rain tire is needed.

There is some sponsorship for tires. Sometimes a tire company sponsors the series, but that does not effect what you can run. Additionally, cash or tires are sometimes offered to drivers if they win, use their tires, and have the car so marked. Most commonly seen in National and ProSolo events. (Pro solo is christmas tree/drag race start)

Just wait until you read the Hot Rod that tested 7 different sets of 200 tw on the Taxi before deciding IMO. For a no holds barred Autox tire you want something that heats up RIGHT NOW like the A6.

The reason you can't find the tires/wheels is because there is something wrong with the pdf.
Pages 116- 131 don't show in normal scrolling. Go to Appendix A and scroll down to C Prepared. You'll see a refrence to rule 17.4 click that and it will take you to the 'missing' page.

Within the SCCA Solo rules, our A, B, E bodies fall into the following classes (warning I have not kept up with the details of all the latest changes).

F Stock (for stock v-8s) You can run DOT R comps, but that will be changing in the next few years.
I'm 99% sure that older cars are no longer allowed in Stock class at National level events.

E Street Prepared (/6 or v-8) Bolt on engine mods (headers, intake, carb). Look in both the appendix and the rules set for restrictions. Restrictions will be on size, and how much they stick out from the original body panel. In other words, also check the rules for flaring.

C Prepared (/6 or v-8) Modified engines, no interior, etc. Tire rules as Gary described above. Slicks are pretty common amongst the most serious compeitors.

Street Modified: All the rules from Street Prepared but engine is free to modify.

Road Tire/ Street Tire classes. This may be available for our cars either locally or nationally. For example Philadelphia Region SCCA has a SP/SM Road tire class for all or most Street Prepared and Street Modified cars on 'street tires'. The specifics are in the Region's supplement solo rules."

Quote:

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I assume I could just get someone to look over the car and they would let me know what "class" I would need to be in? That part is confusing in the rule book too!

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Varies. My region currently leaves it to the driver to figure it although sometimes they will help.

Here's a quick run down:
Stock: Tire size same (or very close) to stock, Rims within 1/2" of stock. Any front sway bar. Any shocks.

Street Prepared: Frame connectors allowed to be welded front and rear with one other attachment point.
Corporate engine swap allowed. Back seat removal may be allowed. Headers allowed, any springs, sway bars, shocks, etc as long as mounted to original points.

C Prepared or Street Mod: If car is modified beyond the above.

Brad... Matt's further details are on-spot. In my opinion, with your car's setup, you'd be in the SM category.. a very tough class to be autocross competitive in... or certainly in C/Prepared... an all-out race class. Some clubs around the country have their own alternate sets of "regional" classes, etc. Rule books can be very difficult to follow, as well as interpret.

As a simplest and most pleasing option, you may want to re-consider and find road course events that allow you to open and use the full awesome power of your car for lapping sessions... could be "competitive" events, or else just "social" fun events.. and eventually lead into competitive events/clubs.

Seek the internet and get to know others in your area who participate... look at your reasonably close road tracks to see if they have clubs/organizations that hold events on their tracks... a typical road course lapping day is ~$200 (+/- $50) in US dollars (some events are 2-days at about $350 US dollars)... and you'll get about 4-5-6 20-30 minute lapping sessions per day.. a blast!... and those ~200 tw tires are ideal choice (per likely rules, if applicable) and will work great for that type of event.. tires should last 1-2, maybe 3 years at most if you're lucky.

Wherever you end up, I'll bet you'll have one of the most popular cars there!!!

We have been racing our cars in SU(Street Unlimited) this season with great success. SU takes the SM rules and removes the make/engine requirements and allows a fairly modded car without them being all out racecars like CP. I plan on running SM for tour next year.

Dan. Thanks for explaining your club's SU class - I was going to ask in your other thread.
Yes. SM can be tough. In fact the times at Nationals last year shows that the best SM cars and drivers are right up there with the best CP cars.
But locally, you never know.
If you look at the PhillySCCA event 7 results I was very compeitive in class. (I stopped at 3 runs because we saw the radiator was leaking). But when the real hotshoes in my class are there, its a much tougher day. For example see the link to results for the August event .

Brad, Mitch knows you and your car better, so maybe thinking track days is a good idea. On the other hand, you should still try autocross and work at getting decent at it. It will teach you discipline and precision. Randy Pobst recommends it, so it must be good medicine.
Randy Pobst's "Epiphany: How I found True Speed"

Matt that was pretty impressive! Faster times than a lot of cars I would expect to be much quicker!

Brad the tire test was brought up by Kevin Wesley in the thread about getting the most out 11.75 brakes. It is yet to be printed in Hot Rod.