Driving Styles

[conrod straight]

Could anyone define and explain the following terms:

- Double Clutching
- Heel & Toe

Thanks

[Dave Brand]

Originally posted by conrod straight
Could anyone define and explain the following terms:

- Double Clutching
- Heel & Toe

Thanks

Double clutching, or double de-clutching as it's more commonly known in the UK, is a technique used for downchanges with (mainly) non-synchromesh gearboxes; it allows engine revs to be matched to the gear being selected.

The clutch pedal is pressed & the gear lever moved to the neutral position. The clutch is then released, the throttle blipped (optional!), the clutch pedal pressed again, the required gear selected & the clutch released again.

Heel & toe is the simultaneous operation of brake & accelerator pedals with the right foot. The toe is used to brake, while the throttle is blipped with the heel. In reality, braking is more usually done with the ball of the foot, while the part of the foot used to blip the throttle depends on the pedal layout.

As you may have guessed, double de-clutching & heel & toe are often used together to allow the driver to change down under braking.

[Tony_Simpson]

Both are linked together with having smoother gear changes when changing down. Double clutching is when you press the clutch once to take it out of gear, release the clutch, then reapply it to put it in the new gear. Whilst it is out of gear you blip the throttle slightly (and after practice) to match the engine revs as you change down. You might notice as you are driving at the moment that as you say change down from 4000rpm in 4th to 3rd as you release the clutch in 3rd the car moves about, becomes unbalanced as the engine revs higher. Double clutching eliminates this by keeping the car settled, thus going quicker on the race track. This is quite easy to do, just takes a bit of practice on the road to get used to the amount you have to blip the throttle, when it is out of gear.

Heel and toeing is similar as most of the time you are changing down gears is under braking. Heel and toeing involves using both the brake and accelerator at the same time, so you brake with the toes and when you take it out of gear, you blip the throttle with your heel. This is quite tricky to do and requries a good amount of practice and well spaced out pedals. It is harder to do with road cars as the pedals are spaced wrong or the brake pedal travels too far etc, but try it and see what happens

The main reason these methods are used is on the race track as you want a stable car all of the time to make best use of it, these methods help keep it settled under breaking. That said it can be done on the road easy enough.

Hope that helps abit,

[Peter Mallett]

Anybody want to expand this to "Gas changing"?

[woodyracing]

dont they both do the same job ?
if so, why use double clutching ?

im getting used to heal and toe, but i found double cluching was much more difficult. does anyone here use double clutching by the way ?

[woodyracing]

Originally posted by Peter Mallett
Anybody want to expand this to "Gas changing"?

is that something to do with eating beans ?

[Peter Mallett]

It's the technique of changing up against the rev limiter. You have to be pretty confident in the limiter and your ability to select gears quickly. I used to do it with my Metro but that was a higher revving engine than the Capri so I had more room to play with.

[Peter Mallett]

Oh,

I use double declutching and heel and toe when racing. I probably don't need to but I got used to it years ago. (Sorry didn't see your earlier post).

[woodyracing]

Originally posted by Peter Mallett


It's the technique of changing up against the rev limiter. You have to be pretty confident in the limiter and your ability to select gears quickly. I used to do it with my Metro but that was a higher revving engine than the Capri so I had more room to play with.

is that where you shift up without using the clutch ?
i heard it can be tough on gearboxes if u get it wrong.

[mattray]

it can be tougher on engines if you miss!

[Lee Janotta]

Originally posted by woodyracing


is that where you shift up without using the clutch ?
i heard it can be tough on gearboxes if u get it wrong.

Here in the states that would be referred to as "powershifting", and yes, especially with a powerful engine in a heavy car, it can blow your tranny to pieces.

I would add to the subject of heel-toe downshifting that one need not use their foot in exactly that position. I have very large feet, and feet it completely natural to use the outside of my foot on the throttle while using the inside on the brake. So use whatever position feels most comfortable. There are some cars, though, you just can't heel-toe on at all. An early Corvette, for instance. The pedals are just completely in the wrong places, no possible way to reach all three at once.

I worry about today's children. With semi-auto paddle shift transmissions, and ABS, will they ever know the satisfaction of threshold braking on a country road from 60 to 10 mph for a tight turn, while executing a perfect 4-3-2 downshift sequence? Jeez, and what about this BS with traction and stability control? Pedestrian drivers are so deathly afraid of a little oversteer! Jeez... There was a time when people drove 400hp rear-drive monsters in the frozen middle of winter, through snow half a foot deep!

I mean, when a Ferrari has stability control as standard, you've got to start to worry...

[Stacy]

Originally posted by woodyracing
dont they both do the same job ?
if so, why use double clutching ?

im getting used to heal and toe, but i found double cluching was much more difficult. does anyone here use double clutching by the way ?

I heel and toe, although more out of sympathy than anything else. I think if you do back to back tests you'd probably find you'd be no quicker.

I don't bother double declutching, it's a dog box anyway so technically you shouldn't need to use the clutch at all. While I can do it, since I have to pay for rebuilds I'm a little easier on the car when I can be..

Stacy.

[woodyracing]

whats a dog box ? i often hear of them.
is it one without the syncromesh ?

[Yimkin]

Originally posted by stacy


I heel and toe, although more out of sympathy than anything else. I think if you do back to back tests you'd probably find you'd be no quicker.

Stacy.

I have tiny feet (size 7 normally, but my race boots are size 6) and find it very difficult in my race car, but easy in my road car. I think at least in part this is because I definitely don't want my foot to slip off the brake in a race situation, whereas on the road that wouldn't be too disastrous.
In the dry I don't think it would make too much time difference, but I'm convinced that it would in the wet due to smoother weight transfer under braking.

[woodyracing]

the problem i get when heel and toeing in my road car is that sometimes with my foot in the middle of the brake and accelerator im actually pressing the accelerator when i just want to be braking. (this is more often when im waring my chunky shoes). No ones actually coached me on this yet.

[Stacy]

Originally posted by woodyracing
whats a dog box ? i often hear of them.
is it one without the syncromesh ?

Yes, no synchros. Direct dog engagement, it means you have to match the revs to the gear you're going to, but gives you a sharper change and lower resistance in the box - therefore less transmission losses.

I didn't get on with it at first and kept bending dogs and all sorts. Then someone explained the workings to me in a manner I could understand and I adapted to it - now I couldn't go back.

[woodyracing]

they are like that in the ff1600's ive driven, they give a clonk but they feel good.

[woodyracing]

does anyone use the handbrake for going around corners ?

[Peter Mallett]

Originally posted by woodyracing
does anyone use the handbrake for going around corners ?

Generally speaking you don't have time to fiddle with a handbrake in a race car. You are thinking of Rally driving which is (surprisingly) a totally different discipline.

There is a type of braking whereby the driver brakes as he/she turns into the corner then rols off the brake onto the throttle as the apex is approached. This has the effect of balancing the car on all four wheels rather than just one corner (the outside front wheel). However it is most successful in front wheel drive because its main effect is to set the back of the car into oversteer. The driver then floors the throttle and pulls the car through the corner. Hence all four wheels are evenly loaded.

Doing it with a rear wheel drive car tends to make the rear too light through the corner and therefore reduces traction at the point when you need to accelerate.

[woodyracing]

so in an oversteer in a front wheel drive car, do you always have to accelerate (instead of brake) to correct the oversteer ?

[Peter Mallett]

Originally posted by woodyracing
so in an oversteer in a front wheel drive car, do you always have to accelerate (instead of brake) to correct the oversteer ?

Strictly speaking, you should only get oversteer in a FWD car if you've brake whilst turning the steering wheel so.................. yes.

[woodyracing]

ok thanks. i'll try to remember that next time i come flying round a roundabout too fast

[Stacy]

Originally posted by Peter Mallett


Strictly speaking, you should only get oversteer in a FWD car if you've brake whilst turning the steering wheel so.................. yes.

Hmm, don't agree. To make a FWD car reasonably quick it will have to be stiff at the rear. Some are very very stiff, to combat the understeer. Some will start coming round with a decent lift, others will oversteer if you've just got it wrong and gone in too hot depending on what's been done with the roll centres.

Indeed I used to have a Corrado VR6 road car which would produce controllable and enjoyable lift off oversteer at will.

Thus with a FWD race car you certainly don't have to be on the brakes to see it coming round.. Any weight transfer will do.

My answer to woody would still be yes, qualified by the fact that hitting the brakes when you've got oversteer in FWD, or RWD, unless things have gone completely Pete Tong is unlikely to sort things out.

Unless you've got power oversteer, in which case you want to come back out of the throttle gently, quite often the best thing to do in a RWD car is get back on the gas to get the weight back over the rear wheels for more grip. In a FWD drive car the same applies although in my experience a lot harder with less opposite lock required.

However, as always YMMV. A lot will differ from car to car due to it's set up, and apologies to those to whom this is sucking eggs.

Stacy

[Peter Mallett]

Originally posted by stacy


Hmm, don't agree.

Now THERE'S a surprise.

Actually you are reasonably correct. However to get the best results braking and turning at the same time is the best use of that stiff set-up. It's the old theory. Make the car do somehing before it surprises you by doing it itself.

[Stacy]

Originally posted by Peter Mallett

Actually you are reasonably correct. However to get the best results braking and turning at the same time is the best use of that stiff set-up.

Praise indeed.

Anyhow, without wishing to over egg the custard you could get the best results from whatever setup you've gone for with, or without, braking. On some, braking might well take the thing too far.