High speed cornering - approaching the limit?

High speed cornering - approaching the limit?

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Discussion

CABC

5,533 posts

100 months

Wednesday 3rd February 2016
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gruffalo said:


Sorry to tight to pay for the full photo but did someone mention a well set up car?

Flat circuit and look at the OSF wheel.
Gruffalo, what tyres did you have?

gruffalo

7,509 posts

225 months

Wednesday 3rd February 2016
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Kumho v70 in the medium compound.

Thinking of slicks for this years outings.


alicrozier

549 posts

236 months

Wednesday 3rd February 2016
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CABC said:
alicrozier said:
Avon ZZR on the Lotus 2-11 (I think I can safely say wouldn't be flat in the Golf or Evora!) smile
oops, i actually meant to ask Gruff about his Cerb with one wheel up!
anyway, good to know about the Avons, they became the Lotus race tyre a few ago right? how are they in the wet/cold?
I have an Elise with AD07s.
A bit sketchy as expected (race series uses proper wets). You'd be better with the AD07.

DiscoColin

3,328 posts

213 months

Wednesday 3rd February 2016
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Frimley111R said:
My problem is that I am scared of pushing to the limit as I am not sure what will happen if I cross it (at high speed!). Yes, I have a Megane RS265 but had an Elise before that. The feedback isn't an issue yet. I am also due to acquire an MG ZS V6 soon so that I can avoid damaging a £15k car!
I think that the best advice to offer you may then be simply one word : Silverstone. It is a real circuit (so not a crappy airfield surface), but has available a few properly high speed corners with the kind of huge run off which will not punish you for hunting for the limit. Be mindful of other cars on the day as usual, but just creep up your entry speeds through the day until you have the information that you need from experience. Nothing written on the internet is going to dial you in like the real thing and perhaps perversely - the country's F1 venue is probably also its best circuit for people to learn their cars and limits (especially if booked into a novice track day). The simple fact of the matter is that IMHO you need a real circuit where there are places where it is comparatively safe to have a spin if you are going to resolve the question. I had a few corkers there when I first started doing track days in my first porker...

Steve H

5,224 posts

194 months

Wednesday 3rd February 2016
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Bertrum said:
Don't get me started on track day instructors!!
And don't get me started on racers and race instructors who think that trackday instructing is easy work and a bit below them....... wink


Seriously though, there's some good advice on here but the best would be to go to a circuit where there is enough room to try things out without causing yourself or anyone else a problem and get some good tuition, having someone in with you that can help judge how far from the limits you are and help you explore them safely is the way forward.

ginettajoe

2,106 posts

217 months

Wednesday 3rd February 2016
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upsidedownmark said:
Bertrum: Yes, I did - it makes a bit more sense with your clarification, though I still completely disagree, but hey ho..

Ginettajoe: Quite possibly biggrin

NJH: 'Late' turn in and apex is generally more pronounced for tighter corners where exit traction is more of an issue.. with a (relatively) earlier turn in for fast ones.. though I'm sure you're right.
Haha USDM ....... what car do you have??

Bertrum

466 posts

222 months

Wednesday 3rd February 2016
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Steve H said:
And don't get me started on racers and race instructors who think that trackday instructing is easy work and a bit below them....... wink


.
Oops. I was going to instruct, then I decided that I didn't want to die..... smile having been in cars with friends on track days I have total respect for you guys that do, and understand why you teach the way you do.

Having someone change down mid corner was a noteable one!!

Frimley111R......don't do that.

upsidedownmark

2,120 posts

134 months

Wednesday 3rd February 2016
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ginettajoe said:
Haha USDM ....... what car do you have??
Formerly a boxster s, more recently an mx5. Ridden with several msv/palmersport guys, but I suspect if there's a match it was a monsoon wet bookatrak day at doninton in a slightly knackered black mx5 with questionable rears..

ginettajoe

2,106 posts

217 months

Thursday 4th February 2016
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upsidedownmark said:
ginettajoe said:
Haha USDM ....... what car do you have??
Formerly a boxster s, more recently an mx5. Ridden with several msv/palmersport guys, but I suspect if there's a match it was a monsoon wet bookatrak day at doninton in a slightly knackered black mx5 with questionable rears..
Yes, possibly, but that will have been a few years ago, I've not had the misfortune of working on their days for a few years now! Work on Javelin days, MLR days, Porsche club days, and odd days for others!!

joe_90

4,206 posts

230 months

Thursday 4th February 2016
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Can you not get a wee bit of understeer dialed in the car..?
In my track car I have it setup (currently) to understeer a bit, as I let my mates etc have a go, and thats prefered to snap oversteer.. However I now want to go faster, so may change it this year.

e21Mark

16,205 posts

172 months

Thursday 4th February 2016
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The only high (ish) speed corner I have been off at was Paddock Hill at Brands. This was down to my staying to the inside later than I had previously and the undulations in the circuit (where it subsided due to the tunnel beneath?) unsettled the car. This, combined with my relative inexperience, meant I was probably heading for an off long before I realised. Fortunately it was only a minute or two before the end of the session, so my mistake didn't impact on others. All I suffered was some embarrassment and a missed lunch break, as I had loads of gravel to clean out of my car and a trip to the Clerk to offer an explanation. I haven't gone off since (in 20 or so track days) and I just chalked it up to experience. I guess it's likely that when you look for the limit, you may stray over it occasionally?

VTECMatt

1,168 posts

237 months

Thursday 4th February 2016
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I found this difficult too and to an extent at The Ring and Spa I still hold back despite the below;

1) In my younger years in my first Elise I must have done 6-7 Activity/Walshy Days and I used the high speed corner to build up my speed, think my best was 95mph last time I went, first time was 70mph and I spun biggrin and again and again........................
2) Regular Driver training on circuit, me sat in the passenger seat watching Dom Palmer taught me so much in the Elise
3) Remember to hit the clutch and brakes as soon as you loose it, in most cases you will stay on circuit
4) Don't overreact sometimes keep going straight and gently lifting off is better than flinging the wheel around, most the time letting the steering wheel go by removing your hands, the car will correct, you just need to remember to catch it!


Digga

40,206 posts

282 months

Friday 5th February 2016
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VTECMatt said:
I found this difficult too and to an extent at The Ring and Spa I still hold back despite the below;

1) In my younger years in my first Elise I must have done 6-7 Activity/Walshy Days and I used the high speed corner to build up my speed, think my best was 95mph last time I went, first time was 70mph and I spun biggrin and again and again........................
2) Regular Driver training on circuit, me sat in the passenger seat watching Dom Palmer taught me so much in the Elise
3) Remember to hit the clutch and brakes as soon as you loose it, in most cases you will stay on circuit
4) Don't overreact sometimes keep going straight and gently lifting off is better than flinging the wheel around, most the time letting the steering wheel go by removing your hands, the car will correct, you just need to remember to catch it!
5) When you've spun a full 180 degrees, it's good to remember how a car steers at speed, in reverse. And that your brake bias is now back to front. Another reason to make sure your mirrors are set before you go onto the circuit.


mcpiston

283 posts

168 months

Sunday 7th February 2016
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Some very good advice here, but you do have to be careful what you heed as some guys on here do this for a living and others don't. You also have to understand the difference between a road and track car handling is night and day (for example road cars will suffer much more from weight transfer, plus breaks and tires will go off much quicker). Keep it smooth and your breaking in a straight line and once you commit to a fast corner keep your inputs to a minimum (I.e. don't be tempted to lift off our steer to hard).
Video here of kirkistown in northern Ireland, which has the fastest corner of any track in Ireland, as you can imagine the talk is always of how fast you can take it (I have seen some mighty spins there).
https://youtu.be/UJh-reosyOI

Hol

8,359 posts

199 months

Monday 8th February 2016
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I have to admit that coming off a track at <80mph over wet grass whilst trying to steer between tyre walls is not a lot of fun.




77racing

3,346 posts

186 months

Friday 12th February 2016
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gruffalo said:
Blanchimont, I am looking forward to learning that one, been there many times but still not sure I have found the best line or entry/exit speed.
Oh but when you do eekbiggrin

77racing

3,346 posts

186 months

Friday 12th February 2016
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gruffalo said:


Sorry to tight to pay for the full photo but did someone mention a well set up car?

Flat circuit and look at the OSF wheel.
If that is camp corner? the only reason you have the front wheel up is that you have to much steering imput on, late in the exit and probably would be faster if you wound off some steering on the later part of exit wink

AdamR172

71 posts

145 months

Friday 12th February 2016
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Some good advice from DocSteve at the end of page 2.

To add to that... use the tyres to help you. The slip angle of the tyre (difference between travelling direction and where the footprint is pointing, because the carcass 'loads up' and twists) is what creates grip. This is maxed out somewhere around 6 to 10 degrees, depending on the tyre. When you get to the optimal slip angle, the tyre will let out a chirp - this is the rubber squirming back into shape as it pulls itself off the tarmac. If the chirp turns into a squeal, you've gone past the optimal slip angle, past the grip limit of the tyre.

If you do get to a squeal, because the car will be set up to understeer in steady state cornering, as long as you don't put any jerky inputs into the car (either pedals or steering wheel) you can just ease off the throttle a touch and continue gently understeering on your merry way. Then, you know to go in a bit slower next time. If you find a chirp, then that's optimal.

The slip angle also creates a self-aligning torque (SAT). The SAT peaks before the optimal slip angle, so the steering weights up as you turn in, up to around 4-6 degrees of slip angle depending on the tyre, and then actually drops off (steering gets lighter) up until the optimal slip angle. This is really easy to feel in a Lotus because they use low caster angles, so the SAT makes up a larger percentage of the overall feedback to the steering wheel. It feels weird since the steering goes strangely light, almost like the front end is floating, but push through it and then you will get the chirp.

The other way to find the limits of your car is to jump in the passenger seat with someone else driving. This can dig up all sorts of liability issues in a 'worst case' scenario, but if you have a mate you trust and is a good pedaller then it's amazing how much you can learn in just a few minutes. I've used this a few times and you can find someone multiple seconds a lap from just one lap with them in the passenger seat!