Heel and Toe.

[Mark Piper]

In rallycross trim Martin Schanche had a claimed 720 bhp out of his Evo RS200 - I'll let you know tomorrow (if you're really interested) what Graham Hathaway's seen....I'd doubt they had that much bhp in 1986, however.

 

I like Noger's response the best, BTW teeth.gif

[wag]

I like double-declutching because its satisfying and makes a nice noise. When I feel clever, I try heeling and toeing so I can brake at the same time. It occurs to me, as an average driver with no race experience, that if you were heeling and toeing in anger and got it wrong (which would be easy for me) it could end in tears.

[Bricol]

I must admit to not seeing the pint of lfb in a rear drive car -

 

in a fwd, the driven wheels overcome the grip of the brakes, so they still rotate/drive, the backs slow/lock promoting oversteer.

 

Rwd car - lfb, you slow the front & you slow the back which you are still driving - cannot see how this promotes oversteer - I would have thought it would lead to understeer if anything? Front wheels now trying to brake AND steer!

 

Never used it in a rwd car.

 

Now turbo charged 4Wd car - allows you to keep boost up and ready for exit of corner. Modulating brakes (as do WRC drivers) allows line to be adjusted in similar manner to a fwd car - I know - it really does cause the nose to tuck in nicely, but you stil have boost and power as you come off the brakes.

 

F1 drivers do it, as said someone else has said, to save that fraction of time when the feet aren't doing anything as the right foot moves from the go pedal to the stop pedal - might as well go a little bit longer, and hit the stop a little bit earlier (relatively, 'cos you are now going a little bit faster).

 

 

Must confess to using lfb in Lancia to get full boost to bang past unsupecting dawdlers - although full arrival of 250 galloping horses to M&S remoulds on a greasy road is exciting on its own!

 

however, if you think it makes you faster, and you like doing it, and you're satisfied - carry on enjoying doing it!

 

Bri

[murph7355]

Aren't Mika, Kimi and Tommi the top 3 finnish, so you stand no chance Simon?

 

And how can you possibly say you know you are quicker than most people and deny you're a braggart in the same thread? I wasn't aware that the population of China had a one make race series for them all to compete in. Or, being slightly less facetious, that all the Caterham owning masses had competed in the race in which you finished 5th... tongue.gif

 

PS I'm quite big too teeth.gif

 

PPS I HNT but don't LFB (impossible for me) or DDC. And I sometimes quite like the sensation of the rears locking up. Unless it ends up in a 360.

 

Edited by - Andy Murphy on 9 Apr 2002 18:20:21

 

Edited by - andy murphy on 9 Apr 2002 23:51:43

[caterhamnut]

Since getting the 7 I have also tried the H&T thing, and with practice will get it right. When you do get it right it is very satisfying!

Having said that, have always giventhe little blip on the downchange bit, if nothing else it makes the driving smooth, which - in simplified terms, helps keep the car from becoming unsettled. (Jackie Stewart school of driving quickly I believe?)

I have yet to apply the H&T version of this blipping whilst seriously braking, but aim to.

Whilst driving in the south of France last summer in the 7, I was explaining the theory of locking the rear wheels whilst changing down the gears to Tessa, and un-intentionaly demonstrated this perfectly whilst going around a very steep down-hill hairpin, which exagerated the affects perfectly!

So, is the 'smooth=quick' theory a correct one?

[Simos]

Karters don't brake and accelerate at the same time I assure you. Karters will lift off and brake hard momentarily to invoke significant weight transfer to initiate turn in and then go back on the power to drift round the corner. This is because karts have a solid axel and so unsticking the inside rear is key to getting round a corner. This constraint does not apply to cars that have diffs. If a karter applied the brake and steering (drive sprocket and brake disk on the same solid axel) then he'd be guilty of the same sloth PC was mentioning earlier and stretching his drive chain to boot.

 

This is slightly more complex in gearbox classes which have disks on the front (ubdriven) wheels also but the reasoning is much the same.

 

Buda, I think you've discovered a new branch of physics ! Trust me the sum of forces on any object at any one time will have a single outcome. You cannot gain grip at the back with accelleration whilst gaining grip at the rear using braking. Either the car is accelerating OR it's braking. Or it's one of those cut and shut cars that shear in half teeth.gif

[Anthony Micallef]

I wish I hadn't asked now eek.gif

 

The Happy 7 Ownerteeth.gifteeth.gifteeth.gif

 

[Jan T]

Good thread.....the only point I can add is that on my recent driving course with Don Palmer I remember his saying I HAD to learn to HNT. Size 12 feet in the SV are well suited to this!

Jan

[Lauben]

Used left foot braking a lot when I was a pizzaracer some years ago, made for some spectacular driving on winter streets, and I was impossible to follow in that Fiat Uno, for anyone trying to follow me to locate the pizza place. Got a lot of yelling by the police though.Learning process is kind of slow, few first carefull attempts all ended up in ditches. Left legs are not sensitive or fast learning limbs. Basically you use lfb instead of the handbreak.

 

Edited by - Lauben on 9 Apr 2002 21:25:25

[martynr]

O.k guys, why not combine the two disciplines, left foot braking and heel and toe, should work really well in a Caterham. If you want to go really quickly and be last of the late brakers use your left foot on the brake, ignore the clutch and change down with a blip on the throttle when passing through the neutral gate. Probably best to practice the disciplines independant of each other though !!

[Alex Wong1697456877]

I tried to learn to LFB (not in the true sense if you follow Peter's thoughts) and also teach myself to blip the throttle accurately enough to downshift without the clutch. It's easier in my VW where LFB is easier thanks to the servo. In the Seven, where more braking force is needed, I find it harder to get the level of brakin right. As for LFB mid corner, if you can make that work to your advantage, you're a much better driver than me. (but then I think you (Simon) know that already? smile.gif I consider myself an average driver and no more)I can't begin to understand the logic in that. I'm learning how to make my understeering Vx oversteer by lifting in the first 1/3 of a corner then reapplying the power. Once the back is unsettled, it's quite easy to drift the car with some controlled oversteer. I guess LFB does something similar?

 

Edited by - Alex Wong on 10 Apr 2002 00:42:40

 

Edited by - Alex Wong on 10 Apr 2002 00:43:36

[Red SLR]

I have been reliably informed that GpB cars can run upto 700bhp....

 

X777CAT

[Jam Mad]

just to clarify this topic for the curious among you who may be confused by the ups and downs of this topic..

 

heel and toeing is the practise of braking with your right foot, and blipping the throttle to smooth out the down change with the right edge of your right foot, operating both peddles at once. used when braking and changing down to smooth out the process, thus keeping the car more stable.

 

double de clutching is the practise of changing into neutral between one gear and another. most often used for down changes, so for example for a 3rd to 2nd change, left foot depresses clutch, right foot comes off accelerator. change from 3rd to nuetral. clutch comes off. blip accelerator with right foot. clutch goes in, right foot depresses accelerator to match engine revs to wheel speed. change from neutral to 2nd. clutch comes off. voila !

 

heel and toeing is essential for fast smooth ( and fun ! ) progress, while double de clutching is a grey area. it comes from the days of no syncro mesh in gearboxes, when it was essential. so while not essential now, in my mind, it not only makes it all smoother, it's much more mechanically sympathetic, as well as leaving the gearbox with more momentum during the process. oh, and it sounds a whole lot better !!

 

the best place to practise ddc'ing, i found, was when i was stuck behind slow traffic, with no chance of overtaking. you then have the space and time to give it a go.

 

j teeth.gif

 

Edited by - jam mad on 10 Apr 2002 09:27:48

[John]

Heel and Toeing takes a lot of practice and requires suitably positioned brake and throttle pedals to be performed. I had to bend / modify my pedals significantly to make them suitably positioned to H and T. At first, you will find it very hard to do and lack confidence in your braking becasue your foot position will feel insecure. Practice makes perfect so they say. I still havent got the hang of it even yet.

 

John

[Old Septimus]

On the old Fiat 500s and old 911s with cold gear oil, you do best to DDC the upchanges as well - but don't blip, engage the clutch in neutral with the engine revs low. In my Batsford 'Art of fast driving' (1958ish) there is a great photo of some punter in a DB4 H&Ting in brown brogues and smart cavalry twills - those were the days, no Sparco boots there!

[cdg]

I've tried heeling and toeing on my Volvo Automatic but it just seems to keep on accelerating. Am I doing something wrong...?

 

Chris.

[rgrigsby]

Hehe...maybe.. but left foot braking works very well in an auto smile.gif especially when the roads are covered in snow and its a hire car!!

 

Cheers

 

Rob G

www.SpeedySeven.com

[EFA]

Left foot braking works very well in a 4.6 litre Range Rover at traffic light GP's according to my wife.

 

As for its application in a 7, its near useless. The popularity of rference has only re-arisen since the Subaru/Evo yobs (I'm waiting....)needed some impressive pub talk as His Rudeness had already pointed out.

 

Heeling and toeing is an essential element of applying racecraft practice to driving your 7. At moderate speeds its pretty easy, but when trying to engage 5th (from 6th) at 9000rpm at the nd of a circuit straight is something of an art.

 

A sequential box and alow inertai engine makes the process even harder - as I am finding! (but you just need match the revs then, and you can forget about the clutch!)

 

 

 

 

 

 

 

Fat Arn

Visit the K2 RUM siteid=red>

See the Lotus Seven Club 4 Counties Area Website hereid=green>

 

[Alex Wong1697456877]

That's another wierd thing. You'd have thought that the more inertia the engine has, the harder or less forgiving it would be, but in reality it's the other way around.

 

Alex

[Christian P]

Probably worth pointing out that, as a prelude to the full H'n'T experience, you can practice your down-change blipping without having to worry about the brake.

 

Let's say you're in fourth: engage the clutch and pull the lever back into third. Then, just before you let the clutch back out, dab the throttle to raise the revs. As the revs peak, let the clutch out. In fact, you can either dab or depress and hold the throttle, but dabbing is what you'll need to do for a HnT change, so try that.

 

Your road speed will remain pretty much unchanged; you'll simply be travelling in a lower gear at higher revs. Doing this gets you used to listening out for the change in revs - surely the most practical way to knowing if you've dialed in the revs at the right time. As above, you'll know you've got it right because there should be minimal pitching and lurching from car & drive train.

 

The next step is to introduce a gentle brake at the same time. But, as mentioned earlier, ensure you are on a quiet, straight road when you first try this.

 

Stick with it - you'll get into and out of corners much harder/faster if you're using all three pedals together, and the smiles get bigger too!

 

 

Christian

[Paul Ranson]

At moderate speeds its pretty easy, but when trying to engage 5th (from 6th) at 9000rpm at the end of a circuit straight is something of an art.

 

Why do you want to do this?

 

You need to have completed your gear changing at the time you have completed your braking. If you downshift later in the process you end up running at less rpm with the throttle closed, with less risk of disturbing the balance.

 

Especially with the sequential, when you need to drop more than one gear, leave it late then bang it down in very quick succession. If you omit to use the clutch then there no need to worry about blipping...

 

In practice the faster you shift and the harder you're braking the better, and the less you need to blip.

 

Paul

[PACR]

Heel and toe is great - your passengers will be really impressed. But I love the noise so much I change through all intermediate gears rather than just slow and then select the correct gear to pull away in.

 

There's a lot of difference between results of the various LFB techniques - try, in a FWD car, stamping on the brake with your left foot when swerving to avoid something whilst flooring the throttle - exactly as if you hit the wrong pedals in a Mini whilst coming down hill on a wet road in a lowish gear and having a pheasant run in front of you! Massive over steer which is then caught nicely as soon as you lift from the brake. However, don't lift from the throttle or you'll point the wrong way.

 

I tried it in my seven at the sprint last year - a bit of drizzle for my final run and I found myself understeering round the top bend. Thought I'll just dab the brakes to get the front to grip. Lot's of oversteer, lift off in panic and pootle down straight over finish line. It cost lots of time and to make it worst didn't even look impressive on video. I used to LFB in an auto all the time, just as the reactions are a bit quicker - obviously my leg reverted to clutch stamping technique!

 

Piers

[Martin H]

Paul

 

Personally I try to get down to the correct gear for the corner as quickly as possible. This means that it leaves me with greater margin for error, and means that approaching turn in, I only have to concentrate on switching from brake to accelerator smoothly, plus steering - I've finished the gear changes well in advance. If I have a lock-up, it means I don't suddenly find myself in too high a gear at turn-in.

 

It also seems that the car is more stable. Getting the blip 100rpm wrong at 6000 rpm seems to have less impact than getting it 100rpm wrong at 3000.

 

Purely down to feel - don't know if this is technically the best way to do it!

[Alex Wong1697456877]

I find the critical part of braking is the first bit when you first hit the brakes so shifting down a bit later in the braking process works for me.

[john aston]

If you want to drive any car properly- but especially a 7 - H n T is essential.And it isnt difficult- I have used the technique for 30 years starting with a Triumph Vitesse via 2cvs and God knows what else and it WORKS. Sounds wonderful too - why anyone would want to buy a 360F1 with a paddle and a box of tricks is beyond me !