craina

The hankooks in question were great autox/track tires 8 years ago, I had a few sets on various cars and they stuck pretty good and lasted quite a while. Hankook has made some great tires in this 200tw category over the years. I hear great things about the rs3's replacement, the rs4. I see them on a lot of my competition in wrl races and they seem to wear like iron and don't give up a whole lot of grip to the top dog 200tw tire bridgestone re71r. The bridgestones are slightly faster but won't last much longer than an 8hr race. Some of the guys in the paddock say the rs4 will go 20 hours no problem...

OP an LSD will do wonders keeping the rear end in check. That said, after an lsd you may find it understeering too much!

mpruden

Completely OT now, but I'm a huge fan of the RS4s and have run them back-to-back with the RE71r. They squirm more than the RE71s and require a bit more finesse from the driver, but can be driven fast and last forever. Hankook has a winner with this tire. There's a reason why they are hard to find. I'm looking at 8 of them in my garage right now

Sorry for the hijack...

cgfen

Agreed, they work well for DE days on a "relatively light", 3200 lb, car. Not as good as NT01 or similar, but better than most 200TW tyres.
But
I like the AD08R's even better

Ciao

samurai_k

Hey all,

Went to another AX event with new tires. Fixed the oversteer problem! On the skidpad I couldn't get the backend to let go and now just wants to push. In contrast, the last time I did the skidpad the back end would let go once I would get going.

Now she is pushing a little too much. Instructors were showing me how to lift and get on the gas to get the back end around on command.

nile13

From trying to occasionally autocross my 993 on street tires... it's not an easy car to autocross (well, compared to my CSP Miata on Hoosiers). The idea here is that you don't really drive a 993 with a steering wheel. it's all your right foot. The steering wheel allows for very coarse and approximate change of direction instructions to the car. All the fine adjustments are done with the right foot.

Additionally, a skidpad, as much as I love it, is not to be used for car setup. Essentially, it's a steady state exercise that teaches you where the limit is, how to make the car step out, how to bring it back in, why countersteering is important and a few other things _if_ the instructor know what he/she is doing. I would not make any car setup decisions based on a steady state like that. It's entirely possible that you are feeling real time dynamic push, something that most 993s are prone to do on an autocross course, especially tight course. Work off of that real time input. Think of your right foot, it's connection to the car, the steering wheel, the ability to swing teh car out but not far enough to induce real oversteer.

k722070

hard to tell if there is a setup issue with such a short clip, but it looks like the nut behind the wheel is pretty loose.
at the 3sec mark you 'crab' over so by the time you should be turning in you've left a huge amount of track off to your right producing a tighter radius corner.
stay out to the right and be patient, use all the track.
go deeper straight ahead at corner entry, try to make one turn input that will make the corner and allow you to unwind the steering wheel as you add throttle during exit.
(it might be that you are trying to make this a two part corner, turn in early then turn again later. if that is the case ignore the above.)

at the end of the 6sec mark beginning of 7sec your car is pointing the wrong direction, it should be pointing at the crane, this forces you to add more steering input getting the car loose.
by the time the car is pointing at/past the crane you are too far out to the right and need to turn in more.
you should be unwinding the steering wheel by the 8 second mark and clipping that last inside cone.
the car looks like it settles well, straightens out quickly and looks easy to control.
I'd say there isn't a setup issue because the car didn't push when you added throttle, it was when you had to turn the wheel more that the car pushed.
that can be fixed by driving the corner different.

Tlaloc75

samurai_k

Thanks @nile13. The car felt night and day different (for the better) this month. Last month with my old tires, the car's back end would come around really easily when too much power or any hint of lift off was introduced in a turn. This month with the new tires, I felt more confident coming out of a turn with more power and could start to experiment with lifting off the throttle in a turn like you described above without getting into trouble that easily. Have a lot to learn still and look forward to more seat time! I agree with you I don't want to adjust the setup of the car yet.

Sorry for the noob question. When you refer to real time dynamic push what does that mean? Is that the weissach effect or something else?

samurai_k

Thanks @k722070. The slalom and the different chicane turns on the other hand were easier as I could easily point the car into the direction I wanted to go and stuck like glue on the course. The sweeping left turn was the hardest part of the course for me. I tired different approaches and at the end I found slowing down as much as I could before entering the turn, maintenance throttle through the first half and then on the second half get on the gas got me the fastest time and I felt the car was not sliding nor pushing as much. The above video example was an extreme case where I did not have the car in the right direction on the back half of the turn.

Here is a video of my best run. Got a 40.1s. I saw only the instructors broke 40s... so I guess I am getting better


Here is a video of the problematic turn for me with the approach I explained above.

samurai_k

18" Continental Extremecontact DW Tuned. They came on a set of OZ Alleggerita 18s that I picked up a while ago and put aside. Date code late 2015 and have lots of tread left.
http://www.continentaltire.com/produ...-20545zr17-88w

Besides the Continentals/OZ set being considerably lighter than my Hankook RS3/Works Brombacher set, the Continental's rears are 285 vs. my old Hankook's are 275, so I do have a bit more rubber in the rear than before. Fronts on both sets are 235s and 18x8.5s.

nile13

It's hard to explain But think of it this way In a skidpad you are static, just doing circles, the rear outside tire is loaded at a constant rate. Lets say you lift just a little. The weight transfers forward, the rear gets a little unloaded, the car starts to step out. Get back on the throttle, bring it back. Or, say, you decide to steer a little more int the turn. The car complains and starts to push. Countersteer a little and you get an agreeable slip angle again and all is good - car is turning at constant speed and radius again. This is the cool part of skidpad when done for long stretches continuously. You start to feel the car and learn to gauge its reaction in slow controllable conditions.

Now, a dynamic condition would be a slalom. Say, you set up for it, got to the back of the first cone, turn to the other cone. What happens? That depends. Let's say that, as most novices, you are late and yanking the steering wheel too much. the car might push or the car might oversteer, depending on where the weight is at this moment. Or, say, you lift or brake. Which rear wheel is loaded at this point? Well, that depends where you are in the slalom and what happened before. What I'm saying is that it's not easy to determine what would happen and why in a dynamic situation like that without sitting in the car and observing not only student's behavior but also feeling what the car does and wants to do at that moment. I was instructing all day yesterday, so there's a good chance that i would right yet another 3-page essay about it here

The other thing you've mentioned is tires. I have a set of 14 year old Azenis (they keep Miata from scraping the ground in the rear instances it's not on Hoosiers). I can induce oversteer fro standstill by pushing the gas pedal partway and making all 130 hamsters under the hood wake up for a split second and move their little God blessed appendages in some resemblance of unison. The car slides its *** sideways. Is that oversteer? In a strict sense, it is. In reality, I would not even try to attempt to make conclusions or change setup because this is a completely static situation. I give this example as an absolute extreme on one end - oversteer from standstill, the most static of statics. Vs, as I've mentioned, a short quick (often offset) slalom, which is the most dynamic of dynamics (the other extreme). What am I trying to say here? Don't make any conclusions from static situations. But! It's very important to feel what the car is doing and that understanding can only come from learning a fairly static behavior. Clear as mud, eh?

At the end of the day, it's all about seat time, Get as much as you can. Understand that track is much more static than autocross, as odd as it might sound. Don't worry much about the car behavior at first get decent tires, which, it seems, you already did. And put your seat time in, event after event after event. Do 20-25 a year and after a few years you'll be more or less versed on what changes the car setup needs and why.. Me? This is my 20th season autocrossing, about 14th instructing. 16 of them in the same car. I just put double adjustable Penskes in last week. Trying to set them up this weekend was like pulling teeth - I have no clue how to really set the car up and just simply drive what I'm given. jut to explain the level of lunacy... up until yesterday I've had variable rear suspension. As in... the rear control arm bushing that were freely moving in and out of the carrier due to the fact that we forgot to put spacers on them a year ago. it finally dawned on me that the car darting out from under my *** is not exactly normal and is pretty scary on top of that. So... listen to my advice with a giant bolder of salt

nile13

Bingo, That;s eh right way to drive a 993 through the turn. Until, that is, you learn to trail brake a bit to help the entry.

One extremely important thing - remember that pedals are not digital switches, They need to be modulated the gas pedal needs to be squeezed lightly The earlier you can start squeezing the gas pedal in the turn, the faster you'll be. The added bonus is that getting on the gas even lightly transfers the eight backwards and literally helps pull you out of the turn, That is something you either already feel or will feel soon with right instruction. A really cool feeling, one of the best you can feel in a car anywhere IMHO. This is where it suddenly feels that the car is becoming your partner instead of an adversary.

nile13

Specific to the video, A little criticism/coaching, if I may:

You are turning very late and too much
You are miles away from teh cones.

A good instructor will have you put your hands on the steering wheel in grid, tell you that you're in a slalom and yell" "turn". After you yank the steering wheel like you normally do (and every novice does), he/she will have you keep your hands on the wheel, put their hands on the wheel and show you how much you really need to turn, at what speed and how to properly unwind the wheel. After a few iterations of that and some head scratching (damn, will the car really turn from that little input?) you'll try to do that on the course. So, if you have good instructors ask them to yell: "TURN!" at you as you are driving, A really good instructor will gauge your reaction time and yell in advance based on that. You will think they are nuts because they yell so early. By the middle of the course you'll actually believe them. And understand that earlier turn starts coupled with smoother and much smaller steering wheel inputs cause the car to not be upset every time. And be amazed that you can actually add speed because you car is not upset from all that wheel yanking.

And, oh, all of this is particularly counterintuitive to those of us who've been driving on the streets for years. That's why 17 year old skiers make the best autocross students. No bad habits and an inherent understanding of what's going on. For the rest of us... well, I started at 30. And long ago realized that I'm a better instructor than a driver

FGL28

NYC993

Couple thoughts...
1) autoX is not a place to make conclusions about set up...and to make the set up work will be different. At slow speeds you are likely to finds lots of under-steer. To share one observation while driving on a wet track...in wet conditions rear wants to come out on both 993 and cayman when I you got too fast...like almost snap over steer that you just have to be alert for and correct early. But when track gets REALLY wet and speeds drop further, car just pushes.
Also, the cure for understeer is trail braking, but at autoX (or on really wet track) you are never going fast enough for that.
2) Dont' judge car set up while you are learning. It may (likely is) diver input that makes car do certain things. I've seen people spend time and money to fix problems that never existed if they just drove differently. Old bad tires and misaligned cars is different, that should be fixed right away.