I have searched and read and learned much.

This is a GENERAL question.

Does anyone see a danger switching back and forth between tires that offer more or less performance? I saw a guy spin off the track because he had grown accustomed to his Cups, but wasn't running them that day.

Any concern that increasing the limits of your car on the track with one set-up will train you to expect limits that your car can't achieve with it's street set up?

These situations tend to manifest themsleves when you are unconsciously reacting. I am not talking about joy riding on the street. If you are conditioned to believe that your car can take more lateral acceleration than it really can...?

I am a 6-10 DE guy who is ready to consider a set of dedicated 18 inch wheels and track tires (19 inch PS2's for the street). At my current level I am concerned that I will be going through a set of PS2s every 6 or 7 DEs...and driving around on those worn tires every day.

Any thoughts on the general Q?

What you don't want me to move this to the Tire and Wheel forum???

Ok, since it is a GENERAL question I will answer "No". I never mistake track capability with street capability, plus your track education should teach you to feel and recognize how your car is performing on whatever tires happen to be on your car. The better you get at knowing your car the less likely you would be to make any sort of judgement error like that, but I have to believe any such errors are few and very far between. I don't know anyone who has used that excuse, I mean made that error before.

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K-Man S

That's one of the dumbest excuses of the many I've heard given by a driver for his error. Did the driver actually say that? If he was truly so out of touch w/his car's handling, tire grip, track conditions, etc. on that day, at that time, he shouldn't have been on the track.

If you are asking the question you may not be ready for R tires. Rs are less forgiving & give less audible warning before they lose grip compared to your PS2s. But you will likely be faster. That means if/when you lose it you'll have less time/distance to recover, travel further, leave the track faster & hit harder. IMO, you should not be on Rs until you really understand your car's handling under all track conditions. In that case, there's no issue of "confusion" going back & forth from street to track tires.

I generally advise DE students to stay w/street tires until they have progressed in their driving skills to the point where their instructors suggest R tires, i.e., they are consistently getting all they can from the street tires. I think you'll learn more & progress better on street tires up to that point.
What run group are you in?

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Dan

Part of it too, is going out in any run session and learning what's going on with your car and the track on that day, or even that time of the day - conditions can certainly change the levels of adhesion during the day. Even on the same track, the temperature may be different, the surface may have changed, or as you point out, you may have changed your tires or setup. A good (and safe) driver will work into a run session (especially the first session of the day) gradually to see what the prevailing conditions offer before you get anywhere near the limit. Another good way to learn a lot about how your car handles is to also autocross a few times. I know some track devotes look at AX as a sort of "junior" style of racing, but I actually find (your mileage may vary) that autocrossing at the limit makes me much better on the track. The time and space continuum on an AX course is so compressed, you have to make decisions instantly, and it teaches you to really "feel" how the car is doing at any one instant. To me, it's the best way to train the seat of your pants. And it's virtually all transferable to the track. If you make a mistake, there's rarely walls or anything to hit, so you can truly test the limits of the car with whatever setup you're running without feeling like your putting yourself or your car in extraordinary danger. Running on a track can feel almost leisurely in comparison - at least to me.

brad

I have to admit, I've never been that interested in Autocrossing. But you've piqued my interest. I think I'm going to have to try it.

Next year I'll sign up.

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Gator Bite
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I am reminded of a comment made by Stirling Moss years ago. He said whatever happens, it's the driver's fault. If a meteor comes out of the sky and hits the car, it's the driver's fault. He should have seen it coming and gotten out of the way.

Obviously an example of British drollery but it is the truth. Even when I had a mechanical failure on my race car, it was my fault because I didn't inspect it properly and see the impending failure.

Something to think about.

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Robert

At the first DE I ever attended, the lead instructor rolled his car when the car in front of him dropped coolant on the track. I was surprised that they placed the blame entirely on the instructor given the circumstances, but it's totally the right attitude and it definitely gave me the right perspective as a new student back then.

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Old saying, "I can teach someone to be a very good race car driver in two years...four years if they insist on using racing tires, two on street tires." A couple of great relatively cheap tires that work great on the track: Falken Azenis and Kuhmo MXs. Tough to kill, great feed back, and cheaper than most out there.

LOL, he spun off b/c he didn't realize how much grip he has, not b/c he wasnt running mpsc.

it's fine to switch tires bac, and forth, but spend a lap or two to get to know the track and the tire. you can drive 100,000 miles old rock hard tires. but realize that you can't push it as hard as you could with sticker new slicks...

There is no issue at all with changing tires. You need to drive to the limits of grip on the track, and the limits change all the time. Damp, track, wet track, hot track, typre wear, dusty track all have an impact. You never go into your first lap expecting to be on the very limit of traction. You need to learn the traction limit and go from there.

And once you use track tyres, it would be unusual to use road tyres on the track, and if you did, you should be expecting to re learn the traction limits.

You should NEVER spin on the road, because even in a competitive tarmac rally you should not be on the limit of traction like you would be on the track. Many rally drivers openly talk about the fact that they aim to drive at 90% of the limit of the car, but no more, consistency is the key.

DT

Exactly what Mooty & Dan said! .....and if it had rained, it would be whose fault?

Last weekend I was at Sebring. We got soaked around noon, I hit the track very soon after it was opened up in my old 'war-horse' 964. I was running on worn out Toyo Proxes in the rain. I had very little grip - front and rear! It was the most fun I've had at a DE in a very long time. I stayed on track until I literally ran out of fuel. I spent the entire time practicing car control techniques. One corner the front end washes out, the next the rear came unglued, braking is unpredictable, you have problems on corner entry and different ones on corner exit. LISTENING and REACTING to your car is critical - which goes back to Mooty's/Dan's point.

Switching tires isn't a problem - it should not condition you "higher grip" levels. If you haven't learned to observe/react to the changing conditions of the vehicle/track - you'll get into trouble no matter what tires you're on.

P.S. If you ever have a chance to run in the rain do it! It will teach you car control in a hurry!

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Go Fast, Brake Late, Don't F*ck Up!

Very good responses here, I think. While I've been running R-compounds on track almost exclusively, for autocross I continue to run streets sometimes and R-compounds sometimes. I think the PS2s are very good street tires for either venue, and I'm still trying to determine whether they might actually be better for me than R-compounds at many autocrosses. The exceptions being very warm and dry conditions. While the PS2s don't have the ultimate grip under those conditions that the R-compounds do, they are so user friendly that they will allow the driver to hold the whole corner at the edge of adhesion without having to make corrections. In contrast, the R-compounds lose traction more suddenly, requiring quick steering and throttle adjustments, costing valuable tenths of a second.