Pedal techniques

[sawood12]

I've read something by Jackie Stewart that might be the steering input thing you've mentioned. He said that if you start your steering input slowly and accellerated the rate at which you turn the wheel instead of quickly snapping the wheel round at a constant speed it allows the car to settle on it's suspension before the maximum lateral G is exerted. The result is a much smoother ride for the passengers and the car is able to make a much tighter turn or make the turn at higher speeds than if you simply turned the wheel. He demonstrated this by driving a car round a track with a cup of coffee on the dashboard at a decent pace without spilling a drop. The technique can also be applied to braking - intead of simply stamping on the brakes, bring the braking force up to max quickly but steadily. This allows you to ultimately apply more braking force and if mastered reduce braking distances. I think this technique is basicly all about doing things smoothly and efficiently.

I've been using/practicing the steering technique and it is definately better. My other half is particularly sensitive to lateral G and after a few bends during a spirited drive will feel nausious but since i've started using this technique she hasn't complained. You do have to be better prepared before entry into the bend which requires you to be thinking ahead which is not a bad thing in any case.

My understanding of Double Declutch is that it only applies to non-syncromesh gearboxes when changing down. You lift the clutch while the gearbox is in neutral and blip the throttle to spin the gearbox before engaging the gear to match the gearbox input gear speed with the output gear. The aim is to avoid crunching the gearbox. The trick is to blip the throttle the right amount to get the speeds right. If done correctly you should be able to engage the lower gear without using the clutch. I don't think it's a technique employed to help you drive faster like 'heel & toe' is - it's just about preserving your gearbox.

 

[Laurence Gibbs]

Anyone wishing to learn about the techniques mentioned and a few more, from an established expert might wish to go to this website
www.carlimits.com and order the excellent DVD "bending the rules" . Which you can watch at home to your hearts content. Then go and book a session with Andrew Walsh (author of the dvd) to put the techniques to the test. . I have no affillation with said company, just a happy customer.

 

[38F3E1]

I'll add my bit which is mainly derived from track driving but a lot of it applies.

First I have always been taught to use the brakes for braking and the engine for either acceleration or balanced throttle. The problems with using the engine for braking is that it a) unbalances the brake bias (ie only brakes the rear wheels in a Porsche), b) you don't get the same feel as you do using the brake pedal and c) it's not good for the transmission and engine (you run a real the risk of buzzing your engine or at least getting the revs up very high if you change down too early to help the braking).

Second is why 'rev match' when changing down? Not for double de-clutching these days because as has been explained it was a technique for when transmissions were a lot cruder. But it is very important if you are breaking at the limit. The reason is that if you are braking at 99% of the safe braking limit and suddenly you let go of the clutch the extra engine breaking will tip the balance over 100% and the car will become unstable. This is particularly important in a car such as a 911 with the heavy back end because you will suddenly loose the back end completely. It can under these circumstances be the difference between having the car turn in and the famous 'through the hedge backwards syndrome'. In modern cars with ABS, traction control, etc you don't experience it so much but try an old car and it becomes very important. And if you are only braking at say 80% anyway its not going to be enough to cause a problem.

Which brings us to 'heal and toe'. At the end of your braking you want to turn the car into the corner. You don't want to change down once you have started the corner due to the nasty effect this can have on the handling so what you must do is make sure the car is in the correct gear before you turn the steering wheel. This means you must change down whilst braking. But because you are on the limit you need to rev match so the engine doesn't become involved in the braking effort. This means you need to use the clutch, brake and accelerator all at the same time. Left foot is used for the clutch and right foot for brake and accelerator. Depending on the car and how the pedals are laid out can influence the way your right foot is used. I use the ball and toe of my foot to brake and the heel to blip the accelerator with the toe at the top of the brake pedal and angled at about 45% with the heel as far up the accelerator as is comfortable (and it takes some getting used to - I find it easy in an old 911 but a PITA in a 993 with standard pedals).

The full sequence for me is right toe/ball on brake with no accelerator, left foot depresses clutch, gear lever out of gear into neutral, right heel goes across at 45% to accelerator and blips throttle, gear level into new gear, left foot releases clutch. I am working the brake pedal all the time. The reason I put it into neutral before blipping the throttle is that if I don't by the time the gear lever goes neutral and into the new gear then the revs have droped to much (simply due to the extra time taken for the gear lever into neutral part).

Ian.

 

[channella]

Ian, Agree with much in your post. Two things to try maybe: First, roll the right foot to allow the outside edge of your foot to blip/control the acclerator when H&Ting, rather than actually using the heel. Second, try a sustained rev gear change as an alternative to a blip - as the box passes through the neutral position apply gas to hold the revs at the level you want, then engage the gear, without allowing the engine to drop below the level required and having to time the change as the revs decay after the blip.

 

[channella]

ORIGINAL: sawood12

My understanding of Double Declutch is that it only applies to non-syncromesh gearboxes when changing down. You lift the clutch while the gearbox is in neutral and blip the throttle to spin the gearbox before engaging the gear to match the gearbox input gear speed with the output gear. The aim is to avoid crunching the gearbox. The trick is to blip the throttle the right amount to get the speeds right. If done correctly you should be able to engage the lower gear without using the clutch. I don't think it's a technique employed to help you drive faster like 'heel & toe' is - it's just about preserving your gearbox.

Whilst I don't use it often, D-D done well can add to a gear change even in a modern synchromesh gear box. For me this is all about trying to keep the car stable and "smooth" so that it doesn't become unbalanced. D-D does to some degree slow down the gear change, but does the control and balance of the car allow you to make better progress, if that is what is meant by "drive faster"?

 

[38F3E1]

For me I prefer to keep my toes/ball firmly planted on the brake pedal and angle 45% to press the accelerator because it feels less likey that my foot will slip off the brake pedal. It's also a much more concious action to press the accelerator therefore you are less likely to do it by accident. But it's personal preference only. There seems to be many ways to do it.

Ian.

 

[38F3E1]

ORIGINAL: sawood12

I've read something by Jackie Stewart that might be the steering input thing you've mentioned.  He said that if you start your steering input slowly and accellerated the rate at which you turn the wheel instead of quickly snapping the wheel round at a constant speed it allows the car to settle on it's suspension before the maximum lateral G is exerted.  The result is a much smoother ride for the passengers and the car is able to make a much tighter turn or make the turn at higher speeds than if you simply turned the wheel. 

Yes agree. I was taught to stroke the car slowly into the turn and it's only when you feel the front end bite that you turn in more aggressively.

Ian.

 

[jw2015]

There's a huge amount of great information there, thanks folks. Makes me even more certain than ever that I desperately need some expert tutition on a track.