Avoiding Downchanging and Braking. Why?

[Mr Whippy]

You can dab the brakes mid-bend to tighten the line, but this only really works on a fwd, since it understeers, and a dab of brakes help bring the nose in, and also, the back end will not go as much since the fwd inherently understeers more.

I don't think I'd trail brake in a rwd, for reasons said, it's your friend till it goes wrong, and you only know it's gone wrong when it's too late...

I can play with my car as it's fwd, go in too hot, lift off or dab the brakes and the tail goes light and comes round a bit. Re-apply the throttle and it just comes back in line.
So easy to drive fast and safely because it doesn't understeer unless your driving FAR too fast, and even then you have options if your gentle and quick with steering and lifting the throttle.

The stiffer and more focussed the car, the more smooth weight transfer and considerate weight transfer/pitch/roll management becomes. If you over-cook a focussed car, the tyres don't get lee-way through soggy suspension, they just get loaded, slip, and you go off the track, or through a hedge

Dave

[GreenV8S]

Mr Whippy said:

You can dab the brakes mid-bend to tighten the line, but this only really works on a fwd

That's actually a characteristic of the brake setup rather than which end is driven.

[The DJ 27]

Don said:

c) Unless you can heel'n'toe to match engine revs to road speed every time you engage the next lower gear and let the clutch up engine revs have to rise to meet road speed and the only thing smoothing this out is the clutch - which will wear away - and costs more to replace than brake pads.

[/quote]

Nice to see a mature discussion on the finer points of driving. I use the heel & toe technique to downchange when I'm 'making progress' in my humble little Seat, as I feel it places far less stress on the drivetrain and makes the whole process a lot smoother. I've tried braking and changing down in the IAM/Roadcraft way (my dad is a member of the IAM, so we have all the books in the house) and it just feels alien, with the engine revs just dropping away to almost idle before a really slow corner.

Would you say this is a valid technique in road driving, or am I just moving my feet around for nothing?

[Joe911]

I guess we need to define whether we are talking about regular cars on the road, or race cars on track - as they are quite different.

If we're talking race cars, then I've not seen a better discussion of this than in "Drive to Win" by Carroll Smith - pages 2-23 to 2-26.

Here's an interesting comment (paraphrased):

At 1g retardation to stop from 160mph requires 855 feet and 7.3 seconds.
At 3g it's 285 feet and 2.44 seconds.
Imagine shifting from 6th to 5th to 4th to 3rd to 2nd in 2.44 seconds and in that time you are modulating the brake pressure to perfection and also blipping the throttle for each downshift to perfectly match engine/road speed. I think not.

Given the power of modern (race) brakes, why put yourself to all that trouble and allow for all the potential dangers (mechanically and in lap time) of it going wrong?

Having said that, there are racers (I have data) that do go down through the gears (although not at 3g braking).

On the road I would tend to go down through the box.

[Pigeon]

tvrgit said:

mindgam3 said: You want a greater load on the front wheels as they are what make you turn in. More load on the front wheels and the less likely you are to understeer. You are highly unlikely to lose the back end from turning in too quickly, if you do, you are going far to fast for the corner. The only thing that will break the rear ends grip is too much throttle, which is a completely seperate issue. A car is much more stable in a corner if the front wheels have just been loaded from braking. I've tried (and read) about it numerous times. Try going into a corner without loading the front tyres and then with and you (should) notice a considerable difference in the way the car corners. By having the gearchange after your braking, the front tyres are not loaded and you are far more likely to understeer. I'm sorry but that's not correct, on so many levels. How many times have you got away with that? 998? 999?

998 perhaps, that might be a Cooper. He won't have got away with 1000 because that would be a Morris Minor and he'd be in the hedge backwards

Don said:

How I've been taught to corner (on track) is to get smoothly off the brakes, get the car flat and then turn in using all the grip of the car for steering rather than for steering and braking at the same time. If it understeers you deal with that then. I've had this from some very fast guys and I believe them.

...whereas Don's Morris Minor flies round the corner and off into the distance.

(It may not be a performance car but I think it is perhaps even more relevant to this kind of discussion... it has a "classic" RWD-but-front-heavy layout, the control inputs and the car's responses are very direct, and it has a complete lack of design features of the type that cover your arse when you get something wrong. If it goes wrong in a Morris Minor it'll still go wrong in a performance car, only in the performance car, better suspension, tyres etc will mean you have to be going faster for it to go wrong, so the results are more serious...)

Don said:

a) You spend more time with the clutch depressed than actually in gear...coasting.. no engine braking during that! b) You don't have both hands on the steering wheel at the very point when you are using up the grip of the tyres to brake and you may need to do something about it. c) Unless you can heel'n'toe to match engine revs to road speed every time you engage the next lower gear and let the clutch up engine revs have to rise to meet road speed and the only thing smoothing this out is the clutch - which will wear away - and costs more to replace than brake pads. d) When the engine revs are raised to match road speed via the clutch there is a "clutch braking" effect on the drive wheels. Under *extreme* conditions and espcially in RWD cars this can upset the brake balance of the car and induce a rear wheel skid - race driver's heel and toe to avoid this - the IAM method which seperates deceleration and gear change does the same - but doesn't require such fancy footwork...

I understand all you're saying but I'm not convinced it all applies unless you're in "race mode" where the ability to save fractions of a second on the approach to a turn is critical. I don't generally brake that hard, so I find that:

(a) simply isn't true unless there's something radically wrong with the gearshift
(b) is true but it's pretty unlikely that it'll have an effect as I won't be braking nearly hard enough to suddenly break grip
(c) is true but has such a limited effect that the clutch still lasts nearly as long as the engine does
(d) already contains the "extreme conditions" clause

I reckon that under normal conditions my deceleration is sufficiently (a) gentle and (b) planned that there is no difficulty or destabilisation associated with carrying out the necessary gearchanging at the same time, and it greatly increases my sense of being in proper control to be in the correct gear for the speed at all times.

I also find that under conditions of extreme braking I instinctively concentrate entirely on the braking and leave the gearchanging until the braking is sorted - but if this happens it generally means I've cocked up because if I hadn't I wouldn't need to brake that hard (it is rare that it is possible to attribute it 100% to someone else having cocked up) so it's a signal that I need to ease up, maybe stop and have a fag.

What I'm having difficulty with is this:

Don said:

2) Does not waste time with intermediate gears - and loss of drive during the changes. Avoids "coasting". 3) Ensures the correct gear for accelerating smartly away from the hazard - so many get this wrong! You can see 'em failing to get away from the junction frantically stomping in the accelerator as sod all happens because they bleedin' well insist on leaving the damn car in too high a gear. Planning to yse the right gear means BEING in the right gear which means a smart getaway!

WRT (2) I just don't get it, perhaps we have a difficulty over definitions? It seems to me that it positively promotes what I would think of as "coasting" - decelerating either with the clutch out or with the clutch in but in so high a gear that the engine's having almost zero effect so the clutch might as well be out.

As for (3) it seems that this is a failure to change gear at all, not simply a failure to do it at the "right" time. Whether you change gear while you brake, or brake and then change gear, at the conclusion of the operation you're in the right gear. It's only if you don't change gear at all that you find yourself trying to pull away in 5th - so I'm afraid I don't understand your point here.

Don said:

mindgam3 said: But as i said before, you are not going to be in the correct gear at all times during the braking. Say you're coming along a dual carriageway in 5th and want to change down to a 2nd gear roundabout, what happens if you want to accelerate when you're say doing 25 mph in 5th in you're braking process, how can you possibly accelerate? Why would you ever need to?

Well, broadening the situation slightly, there's Mr Whippy's traffic lights example... though what I think of first as an example tends to be roundabout-related. I'm approaching a roundabout, say it's a biggish Milton Keynes one and I'm going straight over so the speed I can take it at is determined largely by the traffic and if it's clear I'd hardly need to slow at all; but there are cars on it, cars approaching it, and I cannot yet predict what they're all going to do, so I decelerate, changing gear as I do so so I'm always in the right gear for the current speed, and keep watching what the other cars are doing. At this point I have two "plans" - the one I am currently executing is to slow down and stop at the give way line, since my other-traffic-prediction algorithm (which works on physics, not guessing other peoples' behaviour) hasn't yet thrown up a useful solution. But if it does, as soon as it does I can switch to the other plan, which is to go back on the throttle and accelerate over the roundabout and away. Since I'm already in the right gear, I can do this immediately.

Don said:

This is something that comes with practice. Most people start the IAM with absolutely NO ability to work out what gear they need for any particular hazard.

Don said:

After a while they get good at deciding what gear will be necessary and seldom get it wrong. Once one is good at that then wasting time with unnecessary gear changes actually becomes something you actively don't want to do. In short - the System becomes natural. Actually more efficient than the alternative.

Sorry, I'm not following you again. How does a gear change carried out under braking waste time, compared with braking at the same deceleration rate and then carrying out gear changing at essentially constant speed after braking? Surely that takes more time, unless you decelerate harder to make up? And how is a gear change "unnecessary" when you need to be in a different gear to negotiate the hazard?

I hope this lot doesn't sound too confrontational - I like to learn and I learn about better driving by interacting with people who are better drivers, but I don't accept things uncritically if I have a disagreement, I need sufficient information to apply an informed judgement.

[Mr Whippy]

I've been trying some of this out tonight, been to Sheffield and back to Leeds, so a good journey out.

Hmmm, braking all in one go is handy, ignore the gearstick and just decide before your manouevre where you want to be, when, and what gear.

It took some getting used to and was quite good actually, I felt more in control as I was aiming for a goal pre-manouevre, and then comitting to the turn after reaching that goal, which kinda broke the job into smaller tasks which could be managed more easily observation wise and car balance and control wise too.

Still not 100% convinced that it is always useful, but I feel it can be useful and has a place in good driving know how!
I think I'll try developing this skill a bit more and see how I get on.

Hard to stop taking the gearstick and dropping an intermediate gear with a blib before straight away going down another gear and arriving at the turn point or roundabout or whatever. It truly is a waste of time in such cases, and is easier to just leave it in a higher gear, choose the arrival gear before you brake, and stick to that plan, if conditions change, then you alter half way, simple, if not, your LOTS smoother as I was finding out. You are just planning the whole process rather than shooting from the hip, which means you can effectively think less while doing more in a weird way, which leaves more time for extra observation etc.

Tis growing on me already as you can see Amazon should deliver "roadcraft" on Monday so I'll stick my nose in that for a few days and see what I like

Dave

[GreenV8S]

I don't see it as being a big deal whether you go down through the gears one by one, or miss intermediate gears. Either could be appropriate depending on the conditions, and I might change down early or late in the braking manoeuver depending on circumstances (how busy my hands and feet were, if/when I wanted additional engine braking to change the car balance, and when I expected to get back on the power). I don't think there is any absolute right or wrong here.

The idea of staying in the same gear for the entire time that brakes are applied and then coming off the brakes and coasting during the gear change is far more alien. The worst example is slowing down from high speed to walking pace in order to turn on to a side road. The 'brake first, then change gear' approach has you coasting at walking pace for about a second while you select the gear, then turn onto the side road. The 'change down whenever you want' approach has you braking down to walking pace, selecting a new gear late in the braking manoeuver and then progressively easing off the brakes and turning. This is much smoother, upsets the car less, is less likely to provoke a slide in slippery conditions and generally seems better al round. It is also completely wrong according to RoSPA.

[Platinum]

Mr Whippy said:

That is exactly the type of example I used when trying to convince my g/f of changing down through the gears when she was learning to pass the standard test and the instructor told her to pull up to the lights in 5th.

Thats not what I was taught by my instructor.

"Block change from 5th to 3rd and pull up to the lights. Then the usual handbrake (if appropriate) and into 1st ready to pull away."

I thought the only time when you came a halt in 5th was in the event of a emergency stop.

[Mr Whippy]

GreenV8S said:

Mr Whippy said: You can dab the brakes mid-bend to tighten the line, but this only really works on a fwd That's actually a characteristic of the brake setup rather than which end is driven.

Hehe, well it does work in other cars, but it can get more nasty in them. It mainly works on a fwd as they tend to understeer, so even if you get oversteer, releasing the brakes and a tad of opposite lock will cure it

Platinum said:

Mr Whippy said: That is exactly the type of example I used when trying to convince my g/f of changing down through the gears when she was learning to pass the standard test and the instructor told her to pull up to the lights in 5th. Thats not what I was taught by my instructor. "Block change from 5th to 3rd and pull up to the lights. Then the usual handbrake (if appropriate) and into 1st ready to pull away." I thought the only time when you came a halt in 5th was in the event of a emergency stop.

Did I say that?

Hrmmm

Dave

[cptsideways]

GreenV8S said:

The rigid principle of completely separating braking, gear changes and steering is one of the things that put me off RoSPA. I also didn't get the 'shuffle steer' thing. If you might need to swerve suddenly, then you should hold the wheel in such a way that you can turn the wheel quickly in either direction - and shuffle steer lets you do this. But take the situation where you are accelerating a rwd car (gently) out of a corner in slippery conditions. I might very well need to apply lots of opposite lock in a hurry. In this situation, shuffle steering puts my hands in the 'wrong' position and I am better off crossing my arms to give me three quarters of a turn of instant correction.

The steering geometry will take care of the correction, the front wheels remain pointing in the original direction within a few deg's, the body rotates around them Not a lot of people know that, especiallyu those used to gripping the wheel.

In drift instruction your taught to release the wheel at the point of oversteer (it will effectively rotate by itself) if you add more lock this usually induces a spin. So the shuffle technique is in fact adequate so long as you feather the wheel. Also more than half a turn of rapid lock at anything above 20mph I gauarantee your car will be understeering or about to spin.

[GreenV8S]

cptsideways said:

The steering geometry will take care of the correction, the front wheels remain pointing in the original direction within a few deg's, the body rotates around them Not a lot of people know that, especiallyu those used to gripping the wheel.

Does this work on all cars though? As you know, I'm not a practiced drifter as you are. In fact my efforts at Brands were laughable (still beat VBH though). All my technique and practice is with the aim of minimising the oversteer and getting the car straightened up as soon as possible to avoid losing time. In order to do this I need to get the opposite lock on faster than the car is turning, and get it off again faster than the car comes back into line. Now it may be that the car would do this on its own if I just let go the wheel, I've seen in-car videos from drifters showing this working, but it doesn't feel to me as if mine wants to wind the lock on and off again fast enough without a lot of help. I also want to keep track of which way the front wheels are pointing, this is hard enough with both hands on the wheel let alone if I let it spin free. Maybe with training and enough practice I could learn to let the car steer itself as you are suggesting, but for the moment I prefer to control it myself. Maybe one day I'll find a quiet skid plan somewhere and try the 'let go of the wheel' approach, it's not something that would come naturally on the track though.

[Platinum]

Mr Whippy said:

Did I say that?

It appears not, my mistake.

Fat Audi 80 said....

[cptsideways]

GreenV8S said:

cptsideways said: The steering geometry will take care of the correction, the front wheels remain pointing in the original direction within a few deg's, the body rotates around them Not a lot of people know that, especially those used to gripping the wheel. Does this work on all cars though? As you know, I'm not a practiced drifter as you are. In fact my efforts at Brands were laughable (still beat VBH though). All my technique and practice is with the aim of minimising the oversteer and getting the car straightened up as soon as possible to avoid losing time. In order to do this I need to get the opposite lock on faster than the car is turning, and get it off again faster than the car comes back into line. Now it may be that the car would do this on its own if I just let go the wheel, I've seen in-car videos from drifters showing this working, but it doesn't feel to me as if mine wants to wind the lock on and off again fast enough without a lot of help. I also want to keep track of which way the front wheels are pointing, this is hard enough with both hands on the wheel let alone if I let it spin free. Maybe with training and enough practice I could learn to let the car steer itself as you are suggesting, but for the moment I prefer to control it myself. Maybe one day I'll find a quiet skid plan somewhere and try the 'let go of the wheel' approach, it's not something that would come naturally on the track though.

So long as castor & camber is set up normally then yes it will. Its also to do with the gyroscopic of the wheel where it does'nt want to turn relative to original direction of travel. Its very easy to demonstrate with a fig 8 course

However on some badly desigend cars (TVR's especially) due to crap spring & damper rates & dodgy polar moments, the rear end does not step out in a linear fashion. In this case you can assist the steering rate to help it catch up.

As many have found out & as I see instructing people the natural reaction is to apply opposite lock but then fail to release it when the car corrects, inducing a spin & a hedge cutiing session.

[horst]

No racing or track experience here, and not much technical knowledge either, but I'd like to drive well.

However, I'm not sure if I understand the business of separating braking from changing gear.

For bends, I go through the 5 steps outlined by Don in his second post, though this seems to be by instinct rather than through training.

For roundabouts, though, I tend brake gently but fairly early, and change into second gear or first gear while still braking, so as to be ready to get away without stopping if possible.

At traffic lights too, I'll change down towards the end of the braking phase.

If it's clear I'm going to have to stop, then OK, no need to change. But if the lights could be about to go green, what’s wrong with braking gently, moving up to the lights at decreasing speed and changing down from 4th to 2nd say, so as to be ready?

Occasionally, I’m passed by someone who storms on up to a red light, brakes fairly sharply, and comes to a stop. Meanwhile I brake gently, and, while still braking, change into to 2nd about 20 yards from the stop line. The lights go green and I accelerate away, passing Mr Stormer as he begins to move off. For all I know, Mr Stormer has been keeping brake and gear change rigorously separate, but in this sort of case (which happens quite a lot) I find it so unnatural not to brake and change gear at the same time that I can't even work out how not to do it.

Maybe in traffic-light-stormer situations, I should brake a bit harder, come off the brake about thirty yards from the line, change from 4th to 2nd, then resume braking if necessary or accelerate away?

[DJC]

Mr Whippy said:

I always brake and change to the corner gear just before I turn in. ABS and EBD prevent the need for two handed braking, and I don't brake *RIGHT* on the limit or use max force on the road anyway, so little chance of needing both arms strength while braking. Then we have roundabouts, changing down as you approach means your in the right gear with power to go when you need to. I find it far easier to make progress choosing the right gear all the time. I can't see any benefit not changing down when you feel it necessary. If you thrashing it on the road, and getting the car out of shape as you can't match revs, or getting tramlining under hard braking and need two hands on the wheel, then imho, your driving too fast for your abilities, and need to slow down anyway. In any decent driving car most of these problems are easy to drive around, ie, tramlining, jolty steering under braking, hard to blip the throttle while clutching in to match the revs of the lower gear etc. I fully understand the motives and the ideas behind keeping the car stable and smooth weight transfers, but really only essential on track in a stiff setup foccused car do you need to worry too much about un-settling the car. On the road I wouldn't even pretent to drive that quickly that it becomes a problem because that is probably too fast for the road. Afterall, it's safety first, and there is little chance you can go that fast to need that car balance while still being able to safely stop within the road you can see and all that stuff. Just my opinion anyway. I appreciate being smooth and all the driving lines and all that kinda best practice, but this is just elitist non sense for anything other than a GT3 RS or equivalent on the road. And I'm quite sure that anyone driving that type of car hard on the road in the first place is driving correctly and with respect to engine braking torque locking up the rears and all that, much the same as a sharp lift in a low gear in a fwd while steering can get the back end right round. Good driving practices, and overly anal driving practices. This one is anal in my opinion if it is used totally exclusively in all driving Example: Lets use a straight empty road, rural, cross roads at night, no traffic, lights are green, you approach in 6th. Lights go red 250 yards away. Do you approach in 6th and then wait till 100 yards, and brake, and just before you stop, depress the clutch? What happens if the lights change to green when you are 50 yards away, your in 6th at maybe 20mph and need to change down to 2nd to make progress. I would simply put my car in 4th with a small blip of the throttle, and let the engine brake me all the way to 100 yards, then the same again for 2nd, appreciating that I'll need only minimal brake usage to stop, but be in the right gear to go if they change! Hrmmm Dave

6th gear?
Wtf is 6th gear?

Oh the bleeding luxury to have 6 gears!

[DJC]

Well I have to say I find this thread rather amusing, esp concerning specific techniques, etc.

I couldnt tell you what technique I use to steer. I just steer. I adopt the relaxed and smooth relatively straight arm position of Moss and Farina, yet which allows me to get my wrist to the top of the wheel...as per Mr Brundle or Doc Palmers' advice,
and then just steer.

As for the whole thinking driver thing, well, thats totally against what I regard as good practice. Thinking about driving should be the last thing a driver does, there should be no need to think. Everything a driver does should be automatic, it should happen without him/her/it even being aware of it. *that* is good quality driver training.

Sitrep is where 99% of a driver's brain should be and it is something the UK driver is woefully poor on. The other 1% should be anticipating what the dozy pillock in the 3 series BMW is going to do next.

[Pigeon]

DJC said:

Sitrep is where 99% of a driver's brain should be

Jargon bust requested please.

[DanH]

cptsideways said:

In drift instruction your taught to release the wheel at the point of oversteer (it will effectively rotate by itself) if you add more lock this usually induces a spin. So the shuffle technique is in fact adequate so long as you feather the wheel. Also more than half a turn of rapid lock at anything above 20mph I gauarantee your car will be understeering or about to spin.

Yeah you guys taught me to let go on your course, but I still disagree with it (sorry!). Its only valid to let go if you can't do fast enough rotational steering imho. Good drivers can and it allows you to dampen the wheel which prevents getting tank slaps up the road as you come out of a slide, it also means you can intervene if you need rather than letting the wheel slam onto the lock stops.

>> Edited by DanH on Sunday 4th September 23:18

[DJC]

Pigeon said:

DJC said: Sitrep is where 99% of a driver's brain should be Jargon bust requested please.

Situational Reporting. In other words, Situational Awareness.

[GreenV8S]

DJC said:

Thinking about driving should be the last thing a driver does, there should be no need to think. Everything a driver does should be automatic, it should happen without him/her/it even being aware of it. *that* is good quality driver training.

The mechanics of driving should occur without you having to consciously think about them, but that doesn't mean you should be mentally 'switched off'. I hate zombie drivers!