How do you know how quick you can take a corner?

How do you know how quick you can take a corner?

Author
Discussion

TheBigDawg

Original Poster:

4 posts

75 months

Wednesday 29th August 2018
quotequote all
Now I know that on straights, you can theoretically go a limitless speed, and you won't spin out.

But when it comes to corners, with Newton's Laws of Motion & Centripetal Forces, etc... you can only go so quick, before your tyres will lose grip.

So I'm wondering: how do you know how quick your car can take a corner?
What do you use as a reference to work how fast you can go, and where the limit is?
(or at least, when you're getting close to the limit!)

Thanks for any responses.

mac96

4,435 posts

150 months

Wednesday 29th August 2018
quotequote all
Maybe not a PH response but surely the right answer is by practice and experience, on a track?

On the road, you are unlikely, except by accident, to approach the limit of adhesion on a good surface with decent tyres.

Speed on corners will be limited by being able to stop in the distance you can see to be clear, and I really wouldn't be worrying about trying to find ultimate limits of adhesion.

Not sure if any still do, but one of the American car review mags used to publish max g around a small circular track for comparative purposes. I remember a very upset reviewer discovering that what they insisted on referring to as a Tri*mph Sp*tf*re outperformed a Corvette or something similar... Not useful in the real world!

soupdragon1

4,622 posts

104 months

Wednesday 29th August 2018
quotequote all
I normally just use 'the force'

If the force is down, or I'm getting a poor reception, I just search my feelings and hope that works.

If that doesn't work, I just apply the brake once my passengers start screaming.

mac96

4,435 posts

150 months

Wednesday 29th August 2018
quotequote all
soupdragon1 said:
I normally just use 'the force'

If the force is down, or I'm getting a poor reception, I just search my feelings and hope that works.

If that doesn't work, I just apply the brake once my passengers start screaming.
I think I prefer your answer to mine!

Toltec

7,167 posts

230 months

Wednesday 29th August 2018
quotequote all
mac96 said:
soupdragon1 said:
I normally just use 'the force'

If the force is down, or I'm getting a poor reception, I just search my feelings and hope that works.

If that doesn't work, I just apply the brake once my passengers start screaming.
I think I prefer your answer to mine!
My wife starts saying things like-

3 left, don't cut



Rick101

7,015 posts

157 months

Wednesday 29th August 2018
quotequote all
Limit point. If it's moving away from you, accelerate
Fixed rule never to be deviated from or questioned. Ever. rolleyes

For me, in the dry, its just a matter of observation and checking its clear ahead.
When wet, you really have to gauge what grip is available.

In both cases car type, engine position, tyres even fuel load can make a difference.

Haltamer

2,554 posts

87 months

Wednesday 29th August 2018
quotequote all
Rick101 said:
Limit point. If it's moving away from you, accelerate
Fixed rule never to be deviated from or questioned. Ever. rolleyes

For me, in the dry, its just a matter of observation and checking its clear ahead.
When wet, you really have to gauge what grip is available.

In both cases car type, engine position, tyres even fuel load can make a difference.
What about a scenario with an open limit point; Be that road or track.

To make it simple, Say you are approaching a completely sighted square-ish bend at 60, Leading on to another long straight. Even with cutting offside in optimal conditions, traffic permitting, it wouldn't be appropriate to carry an NSL through the bend, despite being able to see, due to grip limitations and uncomfortable body roll in cars prone to it.

Personally, I'd draw an imaginary limit point using the apex of the corner to gauge position and appropriate speed; Is there a method that you (Or anyone else) would use rather than this, or simply defer to feel?

(Obviating any other clues from the road as to appropriate speeds, such as bend signs, arrows, shipwrecks, advised max speed et al)

wst

3,503 posts

168 months

Wednesday 29th August 2018
quotequote all
The boring answer is "feel".

The scientific answer is "ask a rally driver how they can tell what should be on the pace notes when they're doing 30mph down a stage that they'll later be doing at 90mph"...

Haltamer

2,554 posts

87 months

Wednesday 29th August 2018
quotequote all
wst said:
The boring answer is "feel".

The scientific answer is "ask a rally driver how they can tell what should be on the pace notes when they're doing 30mph down a stage that they'll later be doing at 90mph"...
I'd imagine they may reply with feel laugh

Fortunately, I've not yet had the pleasure of braking traction whilst cornering on the road, but I'd say that I could comfortably, and relatively safely, judge a (Personal) "seven tenths" cornering speed for a given, fully sighted corner, such as the one in my example above; fast, but not probing the limits of traction for safety margins - and I'm sure many others would say the same.

Not through an innate genius, but just by feel of how a car performs in similar scenarios at lower speeds. - Essentially as described in this article: https://www.roadandtrack.com/car-culture/news/a290...
(Read after writing the above wink ) - Similarly to any other physical learning process.

I think the quote that best summarises from the above would be:
That article said:
The human brain doesn't "know" that a Nissan 200SX on 1984-spec all-season tires can't take a 90-degree turn at 50 mph. It has to be taught in a trial and error process that may or may not involve crashing a Nissan 200SX and/or having a really unpleasant interaction with your father afterwards. (Sorry, Dad.)

The Dangerous Elk

4,642 posts

84 months

Thursday 30th August 2018
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As fast as the car can go (in some cases)

https://www.youtube.com/watch?v=W5x9zCO6jsI

Haltamer

2,554 posts

87 months

Thursday 30th August 2018
quotequote all
The Dangerous Elk said:
As fast as the car can go (in some cases)

https://www.youtube.com/watch?v=W5x9zCO6jsI
That gave me an excellent laugh laugh

As fast as the car can go is the golden ticket, really; But how fast can the car go? blah

BertBert

19,709 posts

218 months

Thursday 30th August 2018
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It's actually a really hard question to answer especially with regard to conditions of reduced grip. Wet or even worse, wet plus diesel.

With some practice you can tell as you approach the limit of grip. With practice, skill and enough room you can even recover from going over the limit.

Bert

CrutyRammers

13,735 posts

205 months

Thursday 30th August 2018
quotequote all
mac96 said:
Maybe not a PH response but surely the right answer is by practice and experience, on a track?

On the road, you are unlikely, except by accident, to approach the limit of adhesion on a good surface with decent tyres.

Speed on corners will be limited by being able to stop in the distance you can see to be clear, and I really wouldn't be worrying about trying to find ultimate limits of adhesion.
That really. On a track you have the benefit of being able to go a bit faster each time until you start to find the limit. Over time you become a better judge of where the limit is and thus need fewer goes before you get there.

anonymous-user

61 months

Thursday 30th August 2018
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The fact that insurance for new drivers is astronomical, suggest that "how do you know who fast to go" is answered by "speed up till you crash, then next time driver a bit slower than that"...... ;-)

The vast majority of modern drivers, in modern cars, have ABSOLUTELY NO IDEA WHATSOEVER of where they are currently operating their vehicle within it's dynamic envelop. Typically, they are either using a lot more than they realise (and these days being 'saved' by the electronics) or increasingly, using about 3% of the limit, doing 23.5mph round a bend you can get round at about 100 .

deltashad

6,731 posts

204 months

Thursday 30th August 2018
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For me it's about 86mph

waremark

3,256 posts

220 months

Thursday 30th August 2018
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mac96 said:
Speed on corners will be limited by being able to stop in the distance you can see to be clear, and I really wouldn't be worrying about trying to find ultimate limits of adhesion.
So how often do you test your judgement of the speed at which you can stop in the distance you can see to be clear - on a bend?

Haltamer

2,554 posts

87 months

Thursday 30th August 2018
quotequote all
Max_Torque said:
The fact that insurance for new drivers is astronomical, suggest that "how do you know who fast to go" is answered by "speed up till you crash, then next time driver a bit slower than that"...... ;-)

The vast majority of modern drivers, in modern cars, have ABSOLUTELY NO IDEA WHATSOEVER of where they are currently operating their vehicle within it's dynamic envelop. Typically, they are either using a lot more than they realise (and these days being 'saved' by the electronics) or increasingly, using about 3% of the limit, doing 23.5mph round a bend you can get round at about 100 .
I think that's nicely exemplified by the number of middle aged blokes who've rolled their 80s hot hatch through a hedge.

Now, I wouldn't be able to test the envelope of performance even in a safe environment; Want to determine a realistic stopping distance / practice maximum braking from NSL etc on a deserted strech of road? Big brother is watching, and will be penalising you.

I look forward to having the box out at the earliest opportunity (Next renewal, That is) followed quite swiftly by a car limits day to find the boundaries.

vonhosen

40,506 posts

224 months

Thursday 30th August 2018
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fesuvious said:
waremark said:
mac96 said:
Speed on corners will be limited by being able to stop in the distance you can see to be clear, and I really wouldn't be worrying about trying to find ultimate limits of adhesion.
So how often do you test your judgement of the speed at which you can stop in the distance you can see to be clear - on a bend?
You can't test your judgement.
You can.
Provided it's clear behind you can brake to an emergency stop & see if you stop short of an identifiable marker ahead that prompted the stop.

Haltamer

2,554 posts

87 months

Thursday 30th August 2018
quotequote all
For OP; I'd say the biggest step forward in cornering for me was the HPC Young driver day - (Not a paid placement biggrin ) - Having now experienced some proper cornering, and then being walked-through positioning et al myself, I now have a far better idea than I did going in.
I've still got a lot to improve on, but at least I know where to go!

For any serious gains in ability, it's probably best to consult HPC, Reg Local or similar.

hooblah

539 posts

94 months

Thursday 30th August 2018
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One day, you'll find that limit, and you'll wish you hadn't. Ask me how I know laugh