Sean F

I've done about 10 DE days this year (my first year). I'm in yellow with PCA and recently my speeds have come way up. I'm running a stock 82 SC with Yoko es100's with good tred. My last time out at Lime Rock with NNJR I experienced something new with my tires. On a couple of corners I started to feel my rears sliding. This was happening right after turn in on the right hander at the end of the esses and right after turn in on the uphill. It didn't feel out of control like the rear end was going to break loose but more of a gentle slide and then a real good hookup as I came back on the throttle. So my question is, is this normal and a good thing?

Second question is when do you know that it is time to move to R compound. Both my instructors from this past weekend said that I was ready and that I was at the limit of my street tires. If this information helps, I'm averaging 1:10's at limerock on the stock setup and tires.

Thanks,
Sean

RickBetterley

Hi Sean
Sounds like you are having fun and doing well.
Do you know what your tire pressures were (hot)?

earlyapex

Yes, this is normal.

No. You're not ready. Not to be mean about it, but you have a ways to go before your a safe on stikier tires especially if this is the first time you have experienced your tires sliding. You need to develop and good understanding of why, when, and what to do when your car does something. Your street tires have lower adhesion which means that they break away at lower speeds. This translates into an easier car to handle and that's a good thing. You don't need to be in a hurry to go faster before becoming proficient in car control. You also don't want to jump onto the DOT-R bandwagon until you go through your car and make it safer. Do you feel safe having an accident in your car now? How about at higher speeds?

Keep your street tires. They are helping you learn how to be a better driver. Ten track days is not enough time and you will be hindering your advancement by getting stickier tires that will only mask your mistakes up until the point you spin and then magnify the pain comes from an off because you're going at a higher speed.

I spent allot of time on street tires on the track and autocross before making the switch in tires. I got comfortable and proficient catching many different mistakes. I also got comfortable with sliding the car to make it do what I wanted to do in order to improve my lap times. I improved the safety and my car with a roll bar and single piece seats and harness. I slapped on a set of DOT-R's and the learning curve got steeper. I still use street tires off and on to help me practice.

M758

you are ready for R-tires when you are gently sliding the street tires in every corner on every lap in a very controlled fashion. If not you are not getting all even from street tires.

Sean F

Gotcha. BTW, I do have a roll bar, harnesses and seats. I'm in no hurry to get off the street tires and understand what you guys are saying (and what is said a lot on this board on this topic), it's just been unclear to me what the signs are that it's time to move on.

I guess the fact that I'm asking about sliding is a good indication that I'm not ready. To be more specific about what you're saying, sliding gently into every corner is a good thing and something to strive for?

Rick - my tire temps hot are 36 front and 38 rear. I find anything above that and things get very interesting.

Thanks,
Sean

earlyapex

Sean,
We all want to see you go faster and have fun doing it. As you can see, developing a very strong foundation is extremely important and this takes time, instruction, making mistakes, and recovering from them. At higher speeds, mistakes simply hurt. I liken the development of driving skills to that of skiing. You can feel like you're on rails on the bunny slope only to loose it all when you jump to a black diamond.

ltc

Sean,

Street tires provide you that excellent feedback as they approach the limit, both accoustically (squealing tire is a happy tire) and mechanically (seat of the pants); R compounds pretty much stay quiet right up until the point where they give up grip.

FWIW, I went 2+ years (40+ DE days) on street tires before I went to R's (Hoosiers).....and even now I wonder if that was too short a time on streets.

Willard Bridgham 3

I have a lot of track seat time and I just switched back from R compound to street tires as dragging an extra set of wheels and tires around is work better suited to a burro.......

DE is not a race, it's not preparation for a race and etc

GlenL

Starting on street tires is eminantly preferrable to starting on competition tires. The question of when to go with stickier tires always raises debate. I think the answer is when you're controlling the car well, and smoothly, and are exceeding the grip of the street tires and want to go faster. This is a different point for each person.

I was talking to a guy last night who was positively exultant over the progess he'd made after going to big, sticky tires. (MPSCs) My opinion was that it may have been a bit early for him with just two or three weekends previously but the results were strong.

I'll still drive on the track on street tires for the convenience.

Bottom line: your call. If the people riding with you think it's time, then I'd listen to them.

BTW - Check the prices and factor in that the tires will be old and hard next spring if not used up.

Gary R.

Sean -
Enjoy the controlled oversteer and learn all the limits of your car... slowly. Adding a set of Smart-Racing adjustable sways won't cost substantially more than 4 Hoosiers/MPCS and will help you a lot more in the corners while still allowing the street tires to communicate with you (if you want to add something that is good for both street and track). How about stiffer torsion bars and re-valved shocks? Tires are VERY important but if the car/driver doen't keep the contact patch on the track they won't do spit.


All that being said my car was built from the ground up with Hoosier's and when I asked my builder/friend/coach if MPSC's would be better for me to start with I think he said something like "no". I've never looked back and wouldn't take these off for any reason, They squeal, slide controllably, and communicate perfectly.. but that's me and this car..

Andial951

well I guess I will be selling those victos I just had mounted on 993 wheels.............

Gary R.

And no, you shouldn't be sliding INTO a corner, I assume you meant OUT, yes?

DGaunt

Perhaps give more throttle a little earlier to help lock dow the rear, then throttle steer the rest of the corner?

Bob Rouleau

Sean - good questions both. You've had plenty of feedback on the tires so I'd like to address the first part.

Sliding right after turn-in indicates one of the following:

Too high an entry speed (lowest probability)
Trail braking too much - higher probability
Not enough throttle - to maintain balance on the way to the apex - my guess.

Fast cornering is a balancing act. At turn initiation you should be fading off the brakes (and I mean fading off, not an abrupt release) just as you turn the wheel into the apex. From that point to the apex, too much throttle will make the car go wide (understeer), not enough throttle will cause the back to slide or at least feel "loose". Way too much throttle will cause a spin. The idea is to keep the car balanced. You did the right thing by applying throttle which transferred weight and grip to the back end of the car and stopped the slide. Good job!

Too much trail braking will transfer weight and grip to the front and the back end will want to slide.

Too fast at corner entry night also cause the back end to come around even after you apply enough throttle to balance the car. I doubt that this is the reason you had the wee slide, since corner entry speeds are the last thing we work on. It is often said pros spin on corner entry whereas amateurs spin at corner exit.

So, do any of my theories make any sense?

Best,

Sean F

Thanks all.

Bob - I'm using the PCA method. Brake in straight line (no trail breaking), off the brake, turn in, squeeze on the throttle. The slide is happening as I'm turning in. Could it be that I'm waiting too long to get back on the throttle? Corner entry speed could be an issue as well because I'm having a big problem with understeer in the lefthander. I had a session with an instructor where we tried a number of different lines/techniques to get rid of it and in the end his assesment was that we had found the limit for my car with my setup. I ended up just breaking more and going into the turn more slowly. On all of these corners, my tires are screaming. Not just squealing, I'm talking screaming.

Gary, I am talking about sliding going into the corner not out. I take it from what people are saying that this is something to be concerned about . BTW, are you going to NHIS next weekend? Is your wife hooked on this crack as well? She seemed like she had a pretty good time last week at LRP.

Sean