new to auto-x, tire question
 

I just started auto-x about month ago and I'll be looking forward to going to my 3rd event next week. I'm going shopping for a set of new tires specifically for auto-x, and I was wondering if any experienced drivers here have recomendations. I feel I can push myself much faster through the turns but my tires are holding me back. Any advice about auto-x would be much apreciated.
Thanks for reading,
Sodara

what will the tires be used for? pure auto-x or will they run daily duty as well?

i love the whole falken line up...

falken azenis RT-615. slap them on and drive. not as good in the wet though.

falken FK451 (discontinued) - winning STX tire at nationals... although they were shaved. they do real well in the dry and wet. you might be able to find some leftover stock.

I would recommend you stay on street tires for a season before buying R compounds (Hoosier, Kumho v710, etc). I agree that the Falken RT615 is an awesome tire. I have also heard good things about the Hankook 212, mostly because it comes in STS-friendly sizes (you can't run this class).

What class are you trying to run? Class will dictate wheel size, which is a big part of the tire equation.

I'm running in the SI class. My times so far have been pretty competitve compared to others with experience. Another driver there pointed out my rear tires to me, that the side walls were rolling underneath my wheels. I've raised the pressure higher to compensate. But these tires have been on the car for more than ten years before I bought the car. I'm still learning, and I think I'll take it inch by inch.
Oh, I rarely take my car out. It's strictly used for auto cross, lol and I don't even want to get it wet.

I've not heard of the SI class (but I'm new too)

Well the first thing to decide is if you'll want a true high performance street tire, tire designed for "Street Touring" autocross classes, or a DOT-legal R-compound tire. Of course that depends on what is allowed in your class. In the first category, you'll still get good rain performance and outstanding streetability - I'm running Goodyear Eagle F1s and they are excellent in both rain and dry. However, with a treadwear rating of 280 I'm giving up some grip for durability. DOT R-compounds generally are not for street use beyond driving to/from the course, and unless they are well-grooved and barely worn, you'll have to watch out for rain.

The street touring and DOT R-compound tires are a different beast, and this link should prove helpful:
http://www.grassrootsmotorsports.com...5_tiretest.pdf

Dave

cool, thanks for the helpful info. Oh, SI... special interest. It's where all the newbie's or novice start out.

Hmm, I've never heard of that class either. I am running in CSP, but using street tires which is really making it hard against my competitors. I just bought a set of Sumitomo HTR200 tires a few months ago, but the racing has just about roached those already. If you have the money for real racing rubber, and your class allows it, then go for it. Anything else will be far less than optimal. Good luck.

If the car is used for AX exclusively, I would suggest the Toyo RA-1. It ill last, it's predictable, and it gets better with use, most all other race tires will have a small window in which they work well, the RA1 has a much larger window. Fastest tire, Kumho 710(imho), Hoosier next. If the RA1 is not available, or the Kumho V700 Victoracer is much less expensive, that is another fine choice. After 15 years autocrossing, and road racing I DO NOT AGREE with"stay on street rubber" advocates, there is simply too much difference, you will end up using 1/2 the potential of an R compound for quite a while. This topic has been pounded to death, so search for additional opinions, in the end post your plans. I would not use Hoosier, or the 710 as a starter tire. Have fun, Carl

Makes my choice of Falken Rt-615's feel that much better!

I have an s5 n/a that I autocross. I managed to find a set of stock rims cheap and put a set of RA1's on the car. I gained about 2 seconds on the fastest Miata in E stock just by changing tires.

I am under the impression (at least the club I run with) that you have to run street tires in novice class (which I am in). Have Falken 615s and love them. Dual driving they do heat up a bit on hot days so get a sprayer at your local garden center and bring that along with you if you think you'll get a lot of runs in without time to cool down between them.

There's two competing goals here and you have to pick one. Do you want to become a better driver which will take a little time, or do you merely want to stick race rubber on and go slightly faster now? Making the driver better is always the goal IMO, especially for a newb.

I strongly believe all beginners should do at least a season on street tires. Until you learn how to read what the tire is doing and how to fully exploit the tire race rubber is a waste of money IMO.

Street tires are much easier to read for a newb because they react more slowly and their feedback is much more obvious as to when they're working well and when you're making them mad. Anybody can slap on race rubber and go a little faster now, but the people who spend a little time developing themselves will kick those other's tails shortly down the road.

Damon, I recently made the switch from street to race rubber. The big things I noticed is that the race rubber remains silent up to the limit of traction, and that it sticks like crazy.

Do you mind sharing what things a beginner is really trying to develop that would be different/more difficult to learn on race rubber? Is it simply because the braking rates and cornering rates are higher, and require more precise timing, or another reason?

Dave

In a nutshell street tires are more forgiving and they communicate in a way that's easier for a newb to comprehend. The grip limit of a race tire is much higher, but the window of control at max grip is much smaller and the race tire doesn't communicate as clearly to a newb because it won't beat you over the head a few moments before it slides. The race tire warning occurs very late and is much more subtle. It's there, but most don't feel it without experience.

I find there are two kinds of newbs on race rubber: The ones terribly underdriving the tire, and the ones who terribly overdrive the tire because they never realize something is wrong until the car is sideways.

Here's a graph that illustrates the difference. After a street tire peaks it still maintains near max grip before it falls off. A race tire peaks and then falls off much more immediately.

DamonB - plot them over the same scale, and you'll see the other side of the arguement. Race tire has more everywhere (transpose a torquey motor over a D16 or w/e) even though it has a higher peak, if you dont push it that far you still have more to work with.

I've also seen noobs who instantly did better getting R-comps when they were on street tires sliding all over the place, but then again if theyre used to sliding on street tires and then gobble up the traction of an R-comp is probably form getting used to modulating the throttle.

I haven't disputed that.

I'm saying that the newb can't reap the real rewards of the race rubber because he doesn't know how to fully exploit it. Street tires do a much better job at teaching the newb so he can gain the skills to fully use race rubber later. The race tire has tremendously more potential and the newb just squanders it because he doesn't know how to use it properly, even though he may be going faster than he was on street tires. Different tires on the car do not make you a better driver, and overall better drivers will always be faster than poorer ones.

My argument is no different than arguing over horsepower for instance. Let's take a guy and stick him in a 100 hp car and time him. Now let's give that same car 500 hp. Did he go faster? Sure. Did he go faster because horsepower made him a better driver? Heck no. You can go a little faster and yet still completely suck as a driver.

It comes down to how much of the package's potential the driver can exploit and there's no sense in giving a beginner race rubber when he doesn't know what to do with it anyway. On top of that IMO it hampers his learning curve. This isn't a slam on newbs, it's about putting newbs in a situation where it's easiest for them to learn, gain confidence and flourish. In math class you learned how to add and subtract before you started doing algebra. One builds on the other.

Thanks Damon.

I was aware of the narrower range of peak grip, which is one reason why I hadn't planned on using race rubber this year - I just got a great deal in the exact size/type I wanted. I'm debating whether to continue using them or shred my street tires first. My first outing on the V700 Victoracers was like you said - I had one unexpected spinout, and I was still braking way too early and much less than 100%.

I definitely feel the difficulty of learning on them, especially in the case of autox'ing an FD. First, an FD has tremendous power surge when you go to throttle out of boost.

Second, especially as a beginner, running the whole course in 2nd gear usually gives you a couple of corner-outs where the RPMs are so low that the boost punches extra hard with extra delay.

Third, autox'ing doesn't give you much opportunity to master braking points, which is one place where time is saved. The courses are complex and tricky enough that for a beginner, there's a little too much going on to really focus on the key braking points and using 100% of your brakes. At least that's where I am.

I imagine that on a track and/or a different engine things wouldn't be near as difficult for a new driver.

Dave

It hasn't been long at all when I was there too. I laugh now when everyone was telling me to look and plan way ahead, stay a couple turns in front of the car blah, blah, blah and I'm thinking "Worry about what's way up there ahead? I'm still trying to figure out what the hell the car is doing right NOW!" :p: When it takes all my mental ability to merely drive fast without crashing there's no extra brain power left to think about other things. You complete the run without crashing and call it a success ;)

Fact is there is so much going on there is no way your brain can learn it all at once, you have to take it in steps. For instance I drill people mercilessly about looking really far ahead. Fact is they often can't do it but you drill them anyway. If they're not trying to do it they won't get there. They must push themselves so what feels foreign and peculiar now becomes perfectly normal and unexciting. Then you realize there's something else you haven't been thinking about and you start worrying about that ;)


As for braking, brake a little early. If you brake too early and overslow you can come off the brakes and/or get on the gas earlier. You can fix it. If you brake too late and get in too deep there's nothing you can do but wait, wait, wait, wait while speed scrubs off before you turn in (or you turn in anyway and now you wait, wait, wait, wait while also grinding all the rubber off the front tires). It kills you. It took me some time to really appreciate that the trick isn't how late you brake, it's how early you accelerate.

I also would stick with street tires for at least the rest of this year. You learn the cars limits better, as well as how it acts at those limits. Anyone can go faster with better equipment. Seat time is what you need more than anything. Make sure your times are at the limits with street tires, then you can move up. Remember sometimes you have to slow down to go faster, overdriving is as bad/maybe worse than underdriving the car, its not hard to overdrive, I see it at every AutoX.

Damon,
Thanks for all your comments. This is my first full season and I feel you are right on target. I always forget to look ahead and always brake too late :)

Last event we turned down the boost and ran better times. Kind of contradictive to normal thinking, but we were overpowering the tires and wasted time with them spinning.

I like my Falkens, but will probably look for some used race tires the beginning of next season as I'll be out of novice class.

If you really want to go fast, get some instruction from Evolution.

http://autocross.com/evolution

I spent three days last summer taking their classes.
The instructors were nationals level drivers.

This made a much larger difference in my autox ability than tires ever did.

The three days with motel, food and course costs was ~ $800, approximately
the cost of a a set of tires. :)

Money well spent. I've taken several Evo classes and they helped me tremendously. No amount of money is better spent!