Sledge

Why are they so good for standard-transmission drivers?

It seems to me that accelerating and braking at the same time would be phenomenally crappy for the brake pads.

Rippley

As I understand it, heel and toe is good for maintaining speed through curves. Its done in pro-racing. At times the difference bwtween the guy who spares the car by clutching out and just braking, and the guy who keeps the power on and brakes, is the difference between first and second. Its a racing-thing, and really has no practical application for a normal driver, as far as I'm concerned.

You'll see it done, also, in rally driving, to "provoke" the rear end of a car to step out going around curves on gravel and mud. Stepping on the brakes, not hard, will make the rear wheels lock first. That, combined with turning the wheel and a lose surface, will cause oversteer. Again, not something you wanna be doing to a car that doesn't come with mechanics and spare parts.

Now, double-clutching, as I understand it and please correct me if I'm wrong, is not something newer cars need to have done to them, because they have syncromesh gear boxes. Used to be you matched the revs of the engine with the revs of the wheels, in order to lose as little power as possible, when changing gears. Still used be some cars in racing today because they use straight-cut gears.

I may be talking out of my ass, so get a second opinion...

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peacy

With double-declutching during upshift and downshift you make sure that the engine's rev and the transmission's rev matches. By doing this you achieve a much smoother ride (even under heavy acceleration) and you'll be able to shift down from 5th to 2nd without loosing you gearbox. Some people say that it's not necessary with today's all-synchromesh gearboxes in everyday driving.

Double-declutching during upshift:
lift off -> depress the clutch -> switch into neutral -> release the clutch -> depress the clutch -> switch into a higher gear -> release the clutch -> step on the gas

Double-declutching during downshift:
lift off -> depress the clutch -> switch into neutral -> release the clutch -> blip the throttle -> depress the clutch -> switch into a lower gear -> release the clutch -> step on the gas

During downshift with the throttle blipping you make sure that the engine's rev and the transmission's rev will be the same. You don't need to do this during upshift, since from the first declutching the engine's rev will fall (because of the engine's internal friction), so by the time you finally release the clutch the engine's rev will drop to the desired level.


Heel-and-toeing isn't really useful during your everyday driving.(unless you think any road as a racetrack...) In order to reach the maximum cornering speed you have to enter the corner with relatively high speed (which you cannot keep through the corner). Than you start turning the wheel and braking heavily (since you would slip if you'd keep that speed). But in the meantime you already preparing for the exit from the corner. After you've reached the middle point you can keep accelerating. And even before you reach the middle of the corner you do the heel-and-toeing in order to prepare for the exit. In case of a turbocharged car you can keep the engine above a certain rev, so you'll have maximum boost when you're leaving the corner.

Hope this explains. If I wasn't totally clear, just ask.

Rippley

That's totally what I just said!! Except with instructions...

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castex

Unbelievable!
Peacy, braking and turning at the same time are a recipe for disaster for all but the very talented (ie, me) on road or track. Do your braking in a straight line, and you'll be more than fast enough around the supermarket car park.

The point of heel and toe is to get to the correct gear with the minimum of disturbance to the car's stability while braking before a corner. There's a degree of 'snatch' as the engine speed matches the road speed in a new, lower gear, and blipping the throttle with your 'heel' (my little toe) with the clutch engaged - while braking all the time removes this.

Useful in every day driving for the abovementioned reason, and also for reducing transmission wear considerably; not to mention impressing whole bus queues

Rippley

Wait a minute, Heel-and-Toe have to do with shifting? I was horribly mistaken, and I retract me initial statement, pending revision. Explain to me how Heel-and-Toe has to do with shifting, for I am but a confused little driver...

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castex

Brake with the toe of your right foot.
Engage clutch.
Blip throttle with heel to the required revs.
Change down.
Release clutch straightaway.
Continue to brake.
Repeat as necessary.

The result - a smooth, seamless transition to a lower gear appropriate to the approaching corner. And a noise that goes:
Waaaa....Waaaa....Waaaa...(wait for it)...VrooooooOOOOM!

Mill

This topic can fill a whole day in a classroom at a racing school. To answer the first question, you don't heel and toe to accelerate, you can double clutch to upshift to save your syncromesh in the tranny, especially if you are skipping a gear. Your just briefly puting the tranny into neutral to let the gears spin at the same speed before pushing the clutch again to shift.

Peacy expained what the two are but in racing you should do all your shifting and most of your braking before the corner and heel and toe helps for smoother shifting while your braking at the same time. You can brake slightly in the first 1/3 of a corner (called trail braking) to help put more weight on the front tires to grip more.

Rippley, the techniques for rallying include heal and toe, left foot braking, and hand brake turns.

Peryn

Ripply, i believe you are thinking of left foot breaking. That involves breaking and accelerating at the same time. Left foot doing some breaking, and right foot hitting the gas.

Now nearest to my knowledge, doublt-clutching is useless for upshifting. It slows you down and is complteley useless on any modern stock street car transmission. With the synchros in the gearbox, they will bring the gears up to speed (or down) on their own. On downshifting, double-clutching hasn't been needed for quite sometime either. Not NEEDED, but not neccesarily a bad thing. Im getting confused all of a sudden, but it seems that it is much slower than normal shifting, but can extend the life of your clutch and synchros.

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castex

Double declutching takes longer because you engage the clutch, move into neutral, release, blip the throttle, engage the clutch again, then shift.

HikingHigh

Lot of info in here, dind't read it all..but just thought I'd throw this in.

I heel-to-toe shift every day while driving; once you start practicing it, it becomes very addictive . It's not totally necessary in daily driving, but I enjoy it and it does make things easier once you get it down. And although called heel-to-toe...I, and many others, don't use their heel at all. Use the left side of my right foot on the brake, and the right side of my right foot on the gas. Certain cars' positioning of the pedals makes this easier than others.

Ramega

Double clutching on the downshift also helps keep your weight centered going in to a corner, rather than all of a sudden having all the weight shift to the front tires, which can cause oversteer.

$.02 lighter...

ozzybogan

While we are on the subject, clutchless gearchanges...

Sorry, I couldn't help myself

Practiced this lots, all I can say is don't attempt to learn in a car with a fragile gearbox such as a Subaru :P

peacy

Ohhh man... You have to treat her with respect...

Spyder_Venom

This was a funny thread to read......

Heel-and-toe: is a metod of braking while matching engine RPMs as you down shift (remember, your still braking). When traveling at hi speeds you need to make sure every movement that you make is smooth, and weight transfer while entering a corner or while in a braking zone can cause you to loose control. A car has a imaginary scale that goes back and forth between lateral and horizontal traction... If you have more of one, you have less of another. Everything you do to the car must be smooth but quick. By down shifting while braking you can go deeper into a turn, maintine speed through the apex and accellerate. It is the only logical time to shift, you don't want to do it mid turn when you are using 99% of your tires grip for lateral use, if you screw up - you go off track. If you mess up while braking you run the risk of over revving but unless you really have a brain fart, you will not lock up the rear wheels, just might be a little hard on the gear box (remember, this is in the event that you screw up and don't match revs).


I commonly use heel-toe when trail braking (still braking while turning in). Using your left foot you operate the clutch. With your right you use the ball of your foot to keep braking and with your toes raise the RPM to match the drive line speed so as you let out the clutch (if your using it) there is no distruption.

I still think the clutch is over rated.... I don't double clutch, my car has enough HP to not need to do that ;D It is always going to be faster to not clutch at-all then to double clutch.

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Peryn

How does double cloutching affect weight transfer? All it really affects is how the transmission goes into gear. pretty much all internal. at least so i thought. correct me if im wrong.

Its the rev matching AFTER putting the car in the right gear as you engage the clutch (be it the first or the double/second time that shift) that makes it smoother with less weight transfer.

mystic511

Well, seems like everyone else already said what double clutching is.. but really, heel-toe shifting is just double clutching through a turn.

When entering a turn, you have to brake hard, which means you'll have to downshift. During a race, every second counts, so while you're braking, you're using your heel to blip the throttle to maintaince the revs you'll need to be at when you switch into a lower gear.

You're not actually braking and accelerating at the same time, since the clutch is pressed in. (Braking and acclerating at the same time is a technique called left foot braking. Very useful for front wheel drive cars to maximize their turning potential)

While it's true that today's cars have synchronized transmissions that will bring the engine up to speed with the tranny, it's not perfect. Therefore, a car will lurch as the engine tries to catch up to speed. If you've ever felt the lurch, you will realize that it's not something you want to get during a precision turn. Revving your engine to match the gear is the best solution to avoid the problem.

So that's double clutching and heel-toe.

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miked10270

Hey Sledge,

Double De-clutching, Clutchless Gearchange are NOT things to learn on a PC. Get somebody WHO CAN DO THESE THINGS to SHOW YOU.

"Heel & Toe" is a technique to allow double de-clutch downshifts while braking. It actually involvesbraking with the big toe side of your foot while manipulating the accellerator with the little toe side of your foot. It's VERY difficult (read IMPOSSIBLE) to do properly & effectively in a standard car unless you either have clown feet or have moved your accelerator pedal dangerously close to the brake pedal. There ARE ways to do this, but believe me you don't want to. It was a technique used in motor racing in days before hydraulic braking but it has ZERO relevance in modern road driving.

Incidentally (& speaking as a Class 1 police driver) each of the preceding posts was inaccurate in some way, with some of the advice proferred being outright dangerous.

Firstly, there is ABSOLUTELY NO NEED to downshift while braking. There used to be, back in the days when brakes were mechanical (not hydraulic) and the performance of the brakes was pi$$ poor. Then downshifts were used to allow engine drag to help the braking process.

The correct & SAFE way to slow down is to apply the brake pedal while keeping BOTH hands on the wheel. Slow to the desired speed and THEN change gear to match that speed (double declutch if you want - but in modern synchromesh gearboxes there's no need).

The BIG thing is: Once in the selected gear squeeze the accelerator as you smoothly release the clutch to match engine speed to road speed in your selected gear. THAT IS HOW YOU AVOID TRANSMISSION JERKS AS YOU RELEASE THE CLUTCH.

Secondly, YOU DO NOT BRAKE AND STEER SIMULTANEOUSLY!!! Unless you have ABS brakes (which will automatically reduce the brake effect) you're heading for a skid and a short trip into the scenery. your cars tyres have a limited amount of grip allowing you to brake OR steer violently, but not both at the same time.

Finally, there is a standard drill for dealing with ALL road hazards (i.e ANYTHING other than a completely flat, perfectly straight road) It's:

A) COURSE - Approaching the hazard determine your course through the hazard and plan your vehicles position on the road at each stage.

B) MIRROR - What's happening behind you, is it safe to move across the road to follow your course.

C) SIGNAL - Indicate your intentions using direction indicators or hand signals as appropriate.

D) BRAKES - Adjust to a suitable speed to negotiate the hazard

E) GEARS - Having finished adjusting your speed, shift gears to one suitable for for your new road speed

That's all done BEFORE you get to the hazard.
Once the hazard's been negotiated (steered through) then:

G) MIRROR - Yes. Again. As a final check that it's safe before you

H) ACCELERATE - adjust your speed to match the current road conditions.

The mnemonic is "Can My Safety Be Given Madly Away".

Mike.

Peryn

frankly, the same is true about this post i believe.


Hey Sledge,

Its a great place to learn about it, if you know the info your getting is correct. Learning to do it out on the open road, on the other hand, isn't. Dont try this stuff next time your on your way home from work. Go to an empty parking lot. Or try it the next tiem your on the AutoX track. Dont ever learn new "race inspired" techniques with other people around that could get hurt.

It all depends on the person and the car. Almost every manual drive car i have driven, i have been able to heel-toe in it. It takes most of hte foot on the brake, and just the tip of the shoe on the gas. and i definately dont have "clown" feet. From my personal experience, it has been that most people could heel-toe in most cars, if they know how to do it well.

Woah there.....i dont believe that is true at all. All the modern road-racing courses will tell you about left foot breaking and heel-toe and a few other techniques. All of them make you practice them and tell you to use them. SCCA in particular stresses you learn these techniques to aid in your races. Porsche club of America spends a considerable amount of time in their manual on these techniques. They have a purpose if you know how to do it properly. The key in a good lap times, is consistancy and smoothness. The smoother your transitions are, the faster you can take them. Heel-toe shifting allows for a smooth transition between breaking and acceleration.


So engine drag no longer happens? Downshifting while breaking is still useful to aid in breaking. Save some life on the break pads. Its not nearly as required as it once was, adn you dont *need* to do it in order to stop. But it will help slow you down, and it will save some life on the pads and aid in stopping. Its like using engine drag to moderate your speed goin down a hill. Its not needed...you could pop the clutch in and use the breaks, but its more convenient to use the engine, and will save your breaks. Same idea applies to downshifting while breaking.


While its not reccommended, and istn' the ideal situation most drivers can get away with breaking and turning if they know the limits of their car. I know exactly how much break i can give my car under any situation before locking up the rears or having em kick loose. Again its all in the transition. Smoothly increase breaking, start turn, slightly letting of break....turn some more, start letting of the break and onto the gas and out of the turn...

Its all about knowing your car. More disasters are do to the driver not knowing what they can do rather than what the car is doing. For the amateur driver left foot breaking, heel-toe, and breaking while turning should never be done. Most people in tune with their car can do them without problems and should embrace most of the techniques.

Before you go and try this though, go find and empty lot or go to a track. make your car lock the breaks, take a turn too fast, and give too much throttle and make your back end spin out. Do this repeatedly. Learn exactly how much your car can take. Its all too easy to heel-toe your way into too many revs, too much torque and make the tires chirp or even break free.

castex

Hey Miked, I've met some of you scottish class 1 drivers.

I've even been on one of your courses. Great stuff, I learned a lot.
However, while I have to admit that your qualification is proof of a really high and safe standard of driving, the things I want from my cars...are not entirely compatible with the advice that you give.
Cheers!

brandon11983

Seems to me like this would take longer than:

lift off -> depress clutch -> slam shifter into next gear in one fluid motion -> release clutch -> put foot through floor.

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Pragma

You're right, it does take longer than shifting "normally", but it's sometimes necessary, depending on the car.

With semitrucks, it's pretty important so they don't rip the transmission out - or at least that's what I've been told. (So don't shoot me if I'm slightly inaccurate)

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Neo

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Peryn

There is? hmm....i wonder if its different parts of Europe do it differently then. Not saying your wrong, but all the Englanders i've asked have said that the pedals are the same, as well as the shifter (left-to-right to get into higher gears), its just on the other side.

Castex, i agree completely, and i noticed what i said might have sounded rude. You just put it much nicer. He gave really safe driving advice....but for more..."spirited" driving it wont always cut it.

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Neo

My bad. I was told many years ago that everything was a mirror image of US cars, I really don't know, so I shouldn't have said anything. Sorry

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mystic511

Braking and accelerating at the same time is not unheard of. Of course, heel-toe braking is not for that purpose though. Like I said in my first post, heel-toe is for maintaining engine revs while in a turn so that you will be ready to downshift and have already matched speeds. This keeps your synchro's from having to take that split second to figure out what's going on, and it cuts down track times. I personally heel-toe in daily driving (offramps and such) because i'd rather manually match engine speeds with my tranny then wear down my synchros needlessly. Wear down your syncros and you pretty much have to replace your transmission.

But braking and accelerating is definately used by expert drivers. The technique is called left foot braking. Basically you use your left foot to control the brake, which in turn controls various things. Most obvious is that it can lock up the rear wheels. In rally racing, this is important because locking up the rear wheels will help the driver get his car into thie proper driving position while still accelerating as best as he can. Since the front wheels are still spinning, he can control the exact degree of drift and exit a corner as fast as possible.

On track racing, left foot braking is mostly used by front wheel drive cars. While on a track, it's probably not wise to go into a drift, the braking does help shift weight toward the front. With some expertise, a front wheel drive car driver can actually control his under-steer (notorious in fwd cars), which helps him control his turning line, all while still accelerating at full speed through that turn.

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Peryn

Yeah, left foot breaking involve transfering more weight onto the front suspension, and the front squats down. Acceleration (on fwd will have more traction, and can pull harder) but will make the back end squat down as well, and the car can pull some harder speeds in turns. At least as i understand it.

As for heel-toe...its more for smooth transitions without sudden jerks than it is for synchros. As soon as you move the shifter from neutral into position (whichever gear it may be), whether the clutch is in or not, the synchros have done their job and are no longer part of the equation. As long as you have the pedal pushed in, the clutch that is, then revving then engine will do nothing to the transmission. Heel-toe has nothing to do with synchros unless your double cloutching as well. AS for synchro life, all of mine have lasted as long as the tranny, which has been as long as the engine coincedintally. Anyway, mine all have had 200k+ miles on em. one above 250k so far. So double cloutching isn't neccesary for your synchros, and they wont die if you shift normally. If they go out, they are relatively simple to replace, and by no means indicates the end of a tranny.

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marshall

i reckon half you nerds just cut and pasted all that shit . i would love to see you actually drive a manual............now that would be a fucking joke!!!

Peryn

Thanks for the intelligent reply. Lots of useful info on that one. Im sure that helped clear it up for the original poster.

If you have absolutely nothing to say, dont. Dont just come in here with pointless comment. Besides, i think we all figured out who the "joke" is.

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Rippley

That was uncalled for...

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