Expert driving advice needed...

[Jonnogibbo]

Hi all,

I've just finished compiling a new website on ‘driving techniques for the track’ and I would be really interested in some constructive criticism from drivers who have some experience (I've been told this is the best place to come!). The site is aimed at drivers who are reltively new to the motorsport scene but would like to get involved and learn a bit more about the techniques.

Comments in general would be great, especially areas which could be improved or aren't clear. These are the two sections which are relevant:

http://www.drivingfast.net/techniques.htm


http://www.drivingfast.net/car_control.htm

Many thanks!

Jon

[EdLeake]

I'll take a look after work, had a quick sniff and from what I can see the java examples are pretty good.

[dtype38]

Hi Johnno and welcome to 10-10ths.

Had a quick look though and I think that's a great effort as an introduction to fast driving. Couple of thoughts... (three actually)...

In the introduction to the section on techniques you say "This section takes the theory illustrated in Car Control and applies it to real situations and we cover techniques from track driving to handbrake turns.", but actually I found as much stuff on "application" in the Car Control section (eg about weight transfer to achieve turn in) as in the Techniques section. Perhaps it would be worth a quick review of what you describe as "theory" and "application". Or maybe just a slight alteration of the section description.

On a more specific item, I don't totally agree with your ideas about braking with and without wheels locked. AFAIK you can always slow down quicker when the wheels are turning than if they're locked... on pretty much any surface! So the objective it always to brake at or below the limit of adhesion of the tyre but never above. Inevitably though, sometimes you will arrive at a corner too fast and in attempting to brake hard enought to make the turn in, you over do it and lock the wheels. This could send you straight to the scene of the accident... particularly on wet or slippery surfaces, BUT, if at the moment the wheels lock the brake pressure is released to allow the wheels to restart then reapplied (but slightly less than before) you might still avert disaster. Ideally this second attempt will sort the problem out, but often this attempt will relock the wheels. In this case you simply repeat the procedure. ABS is simply and automated system to do this and will still produce a shorter stopping distance than locked wheels in virtually all circumstances.

Most race cars, however aren't allowed ABS. So when you see a brief puff of smoke from the wheels of a race car under braking, then he got it right the second time. When he takes quite a few attempts (accidentally or deliberately) its called Cadence Braking and is effectively a manual version of ABS. Try watching some slo-mo of F1 drivers on the limit into a corner and stop-starting the inner unloaded wheel to both impove the braking and prevent a flat spot. That's cadence braking by the best in the business!

One last thing... on fast starts. Your description is fine for a road clutch, but as soon as someone fits a full race clutch (and perhaps flywheel as well) the technique alters a bit. Race clutches have little or no capacity for slip and are used virtually as an ON/OFF device. They actually need to be "dumped" at the start not to overheat them. The theory is that a tyre rotating faster than the speed of the car will produce more acceleration than one moving at the same speed (watch a dragster start if you doubt it). Over do it though and you won't go anywhere at all! The process then is one of generating SOME wheelspin, but controlling it to get the best overall effect.

Anyway, that's my two-penneth. Hope you get some more replies soon.

[Jonnogibbo]

Thanks so much for your comments, I'll certainly have another look at that description.

I knew the braking section would be controvertial! To be honest I really struggled to find any measured data which compared locked wheel braking vs ABS in the dry - if there's any info out there I'd be really interested to have a look. Completely agree that ABS will stop you faster in the wet / slippery conditions with the added bonus of being able to steer, but in the dry from a simply "stop as fast as you can" scenario I'm not sure if it's completely clear cut. I'm basing this on the fact that the friction differences in locked wheels vs rotating wheels in these conditions is much less than in the wet. But I could be completely wrong and quite a lot was assumption!

On the start side of things, I've only ever competed with a "fast road" clutch so have no experience of racing versions, many thanks for the advice.

Really interested in other comments in the ABS vs no ABS debate (in dry track conditions).

[dtype38]

Originally Posted by Jonnogibbo

..... Completely agree that ABS will stop you faster in the wet / slippery conditions with the added bonus of being able to steer, but in the dry from a simply "stop as fast as you can" scenario I'm not sure if it's completely clear cut......

I stand to be corrected regarding a road car on warm dry public roads, but last time I looked there wasn't much call for a straight line "emergency stop" on track. The situation only tends to come up approaching a corner when actually stopping is the last thing you're interested in.... so the ability to steer isn't so much an added bonus as an essential.

[Jonnogibbo]

Ha - very true. I need a rethink on this

[JohnD]

Second hand, but experience of a real life incident.
A colleague was faced with an accident on the other carriageway of the Mway, in dry weather. A van crossed the central barrier, into his path. A fast but not competition driver, his instinct was to brake as hard as he could, and steer away. Afterwards, he could see the dotted line of tyre rubber his car had left on the tarmac and the curve that he had been able to steer. He said that without ABS he couldn't have avoided the rogue car.
John

[THIM]

There are diffrent ABS systems, if we're talking about track-adjusted one, it should be better, also on dry. A lot depends of the driver and the brake bias in the car.

Jonnogibbo, nice website

[Hayden Fan]

I have tapped on my steering wheel for every race I run in,

"Brakes = Best Friend"

[bdwoody]

nah, brakes= worst enemy of speed .....

[Hayden Fan]

Originally Posted by bdwoody

nah, brakes= worst enemy of speed .....

But, for me there are my buddy. Two crashes by running into the person in front of you is not a good way to start out your first races in open wheel cars.

[dtype38]

Please chaps, could we keep this to feedback on Jonno's website rather than slip into a general discussion about braking. Ta.

[Jonnogibbo]

Thanks for the comments, braking is more complex an issue than I originally thought!

Originally Posted by THIM

There are diffrent ABS systems, if we're talking about track-adjusted one, it should be better, also on dry. A lot depends of the driver and the brake bias in the car.

A track adjusted ABS sounds quite specialist - can you change the programming of an ABS module in a similar way to remapping an engine ECU or would this be a brand new system?

[Tim Falce]

Originally Posted by Hayden Fan

But, for me there are my buddy. Two crashes by running into the person in front of you is not a good way to start out your first races in open wheel cars.

Yes but was that due to lack of brakes or mis-judging distances?

[Tim Falce]

Originally Posted by dtype38

Please chaps, could we keep this to feedback on Jonno's website rather than slip into a general discussion about braking. Ta.

The title is "Expert Driving advice needed" I think braking comes under that banner.

[AU N EGL]

Interesting. On another web site this same post was done by someone name David.

Come to one of my High Performance driving schools then go to several racing schools you will learn quite a bit.

[dtype38]

Originally Posted by falcemob

The title is "Expert Driving advice needed" I think braking comes under that banner.

Well excuse me for coming out of my corner! I take it from that comment you think sticking labels on your steering wheel and admitting to punting people up the back are constructive advice on braking. Err, I think we'll have to agree differ on that.

Goes back to corner.

[Tim Falce]

Originally Posted by dtype38

Well excuse me for coming out of my corner! I take it from that comment you think sticking labels on your steering wheel and admitting to punting people up the back are constructive advice on braking. Err, I think we'll have to agree differ on that.

Goes back to corner.

Did I say that?

[dtype38]

I'd reply to that, but it would be even more off topic than the meanderings about braking.

So I won't.

Oh, ********, I just did.

[AU N EGL]

Originally Posted by dtype38

Goes back to corner.

Remember Late apex that corner, then roll that throttle to the floor and track out . . ..

[JamesH]

Originally Posted by dtype38

I stand to be corrected regarding a road car on warm dry public roads, but last time I looked there wasn't much call for a straight line "emergency stop" on track. The situation only tends to come up approaching a corner when actually stopping is the last thing you're interested in.... so the ability to steer isn't so much an added bonus as an essential.

From my relatively limited race experience, I would think that any sort of locked wheel braking would be less effective that threshold braking (Except - Snow and gravel - where the pile up of debris on front of the wheel gives better braking). You cannot steer for a start, and you then need to get the wheel up to speed again on release, which takes energy - supplied by your momentum which must therefore reduce the Kinetic energy of the car. Therefore its not as quick as keeping the wheel rotating.

I think that locking the wheels also flat spots the tyres, overheats them in that spot reducing grip, and also reduces grip because of smoke emitted from the tyres contact patch against the road (Like a saucepan with water underneath). Not so bad in the wet though as temps are lower.

Other thought would be - if locking the brakes was effective in racing, why doesn't everyone do it...

[AU N EGL]

Originally Posted by JamesH

Other thought would be - if locking the brakes was effective in racing, why doesn't everyone do it...

James is correct. and if you have to ask this question, then it is TIME to get yourself to a race school. Not write about it.

Look up the books by Ross Bentley.

Speed Secrets is a good one to start with

[dtype38]

Originally Posted by JamesH

Other thought would be - if locking the brakes was effective in racing, why doesn't everyone do it...

Obviously not clear in my comment, sorry. If you read the section on braking in Jonno's website, it suggests that locked wheel will slow you quicker than ABS or Cadence Braking. I had pointed out earlier that I didn't think this was the case, and that both braking methods were ways of recovering a bad situation. I was't suggesting that locking up was deliberate... just that it can happen when you're racing and that cadence braking will give you more chance of getting round the corner.

I don't think its fair to say that limit braking is best and therefore any sort of lockup or cadence braking is poor driving. It happens in F1 and if the best drivers in the world outbrake themselves occasionally, I'm gonna forgive myself for doing it. If you've never had that problem then either you're a brilliant exponent of the right foot... or you ain't pushing hard enough

I shall now go back to my corner and will be sure to arrive at it's apex under complete control.... which is more than I can say for my efforts into Turn 2 at Rockingham Motorspeedway today

[JamesH]

Just to be even clearer, I wasn't commenting on your comment, but on the concept of locking the brakes as an effective way of slowing down. Which I also think is incorrect. So, in précis, I agree with Dtype38!

James

[terence]

I really was not going to make any comment on here but,why were cadence braking,or ABS invented.??