Let me get this right.....

Heel & Toe is only for downshifting while braking. You dont depress all 3 pedals at the same time, its more of a dance. 1st You hit the brakes then while staying on the brakes you disengage the clutch then take your foot off the clutch then roll your right foot over so its on the brake & gas at the same time & Blip the gas to punch the RPMs up quickly then before the engine revs drop you quickly shift to the next gear down. It should take 1/2 a second & the nose of the car should remain at the same level all the time not go up & down

 

The main purpose of "heel/toe" downshifting is to "match" the rpms of the engine to the expected rpms in the next lower gear... so that you don't cause engine braking which can throw off the balance of the car. The only reason to do this is if you are racing on the track and are doing threshold braking, where a sudden additional braking can cause the car to spin out.

When you are braking hard, you should be pressing on the brake pedal with the ball of your right foot with constant, hard pressure, almost to threshold. Then clutch goes in, shifter goes to neutral, clutch out, "blip" the throttle with the side of your right foot (not the heel -- too awkward a motion otherwise), then clutch in, downshift, clutch out before the revs drop.

It takes a fair amount of practice. Most important, constant pressure on the brake pedal. If you do it right, the downshifts should be smooth and the only braking you should feel is from the brakes, not the engine.

Hope that helps.

 

wait...so you'll be changing gear without depressing the clutch??? That sure can't be good for the transmission or clutch. I always thought that you blip the throttle with the cluth depressed, shift, then let it out, all while on the brakes the whole time.

 

Dan you are correct, probably just a momentary lapse in concentration while he was typing the post.

 

No, you always clutch in when shifting.

The sequence :

1) Approaching 3rd gear corner after fast straight taken in 4th or 5th.

2) Upon entry start braking with ball of right foot.

3) While right foot is braking, left foot clutches in.

4) Gear is freed to neutral.

5) Clutch is let out.

6) Before braking is completed, pivot right foot so that the heel (small footed people) or lateral edge of foot (big footed people) quickly blip the throttle to increase the revs. The revs need to be anticipated so that the synchromesh doesn't have to do any work when the lower gear is selected. This "rev matching" takes judgment and practice.

7) After revs have been blipped up, depress clutch.

8) Select lower gear.

9) Clutch is let out for the final time. There should be no engine braking, no "lurch", no abrupt weight transitions if done properly.

The manuevre is essentially complete at this stage. The steps may seem slow, but everything should be smooth and fast. If additional braking is required, you can keep the foot on the brake a tad longer. Or do something else. When tracking a FWD car, I've learnt to quickly heel-toe on corner entry then rapidly bring my left foot to the brake and the right foot to the throttle to left-foot brake for fine adjustments mid-corner, because I find I have better control this way. For balanced RWD cars, I don't really need to left-foot brake to balance the car, simple throttle control is sufficient, so I just heel-toe, then just accelerate out of the apex.

 

NO, NO, NO! That is double-clutching! And a total waste of time.

Don't confuse the guy. This is the technique:

1. Start braking (yes, with the ball of your right foot).

2. Clutch in (still braking)

3. Shift to next lower gear (still braking).

4. Blip throttle with the right side of your right foot (still braking).

5. Clutch out (still braking).

6. Off brake (and now you're set up for the next corner).

This technique, of course, is moot if you drive a car with flappy paddles.

Merry Christmas!

 

P.S. Heel-and-toe lessons are available. References upon request.

 

I reacll a thread on another site where the subject of matching revs came up. I try to do that when I downshift with a blip of the throttle. It was pointed out to me that while that is kind to the engine there is a different goal for timing maybe the "layshaf" or something with the engine speed.

Anyone know about this. I'll try to find the other thread.

 

I found it, two great threads on " double clutching" and "shifting"

http://forums.corvetteforum.com/showthread.php?t=212943

and

http://forums.corvetteforum.com/showthread.php?t=429539

========================================

everything you ever wanted to know about Double-clutching. (and why you don't have to know it) By Phil Ethier ([email protected])

--------------------------------------------------------------------------------
The basis of misunderstanding about double-clutching, rev-matching and heel-and-toe is a lack of understanding of the basic way the engine/clutch/transmission combination works. So take a deep breath and follow along.
What do synchros do? They are used to make the the layshaft match the gear that you are going to. To do the job in a car without synchromesh, you have to make the layshaft go the speed of the new gear yourself.

(Note, I have always just called the gears on the layshaft "the layshaft" so it is easier to visualize. This is a schematic description, not an analysis of which gear slides where on which shaft, or how synchros work, or what oil to use for them. So if you don't agree with the schematic concept I outline here, tell me where I went wrong, and we will look at it. Technical statements about gear movements on shafts or the like will be sent to the bit bucket. I know that modern transmissions are constant-mesh but it really does not change the concept.)

You have three rotating parts in series (1,2,3) with two ways to connect and disconnect them from each other (A B):

1 A 2 B 3

engine -> clutch -> layshaft -> gear selector -> various transmission gears

1) The engine speed is controlled by the throttle alone when the clutch is disengaged ("in"). It is equal to the layshaft speed when the clutch is engaged.

A) The clutch disconnects the engine from the layshaft when you step on the pedal.

2) The layshaft speed is equal to the engine speed when the clutch is engaged. The layshaft speed is related to the road speed when a gear is selected. Therefore, when the clutch is engaged AND a gear is selected, the engine speed is related rigidly to the road speed. (Nobody spins the wheels in this schematic outline!) When the clutch is disengaged AND the selector is in Neutral, the layshaft coasts down freely, regardless of either engine or road speed.

B) The gear selector disconnects the layshaft from the transmission gears when you select "Neutral", and connects the layshaft to a specific transmission gear when you select one.

3) The various transmission gears are being pushed around by the road speeding under your car via the differential and driveshafts. All of them All of them are spinning at different speeds in rigidly defined relationship to each other. If your tires are not slipping, the speed of the system is rigidly proportional to your road speed.

If you have working synchromesh: You are loafing along in Third gear and want to change to Second gear. When you put in the clutch and change the gear selector from Third to Neutral, the layshaft is going a particular speed that matched Third gear at the present road speed. If you do not change your road speed (your brakes are broke, say), the layshaft is going too slowly to match Second gear. As you approach the Second gear selection, the synchros will speed the layshaft up to the same speed as Second gear is now rotating. How do they do that? Ask a mechanic. They just DO it. I have a rough intuitive grasp of how they work, but it does not matter here.

If you have no synchromesh (Crash Box City): You are loafing along in Third gear and want to change to Second gear. When you put in the clutch and change the gear selector from Third to Neutral, the layshaft is going a particular speed that matched Third gear at the present road speed. If you do not change your road speed (your brakes are broke, say), the layshaft is going too slowly to match Second gear. (Sound familiar so far?) As you approach the Second gear selection, the gears go GRAUNCH.

What should you have done? This:


Push in clutch Layshaft equals Third gear speed

Select Neutral Layshaft coasts

Let out clutch Layshaft equals engine speed

Blip throttle Engine and layshaft speed up to Second gear speed and a
little

Push in clutch Layshaft coasts

Select Second No GRAUNCH if you have the speeds right. Ideally,
layshaft has coasted down to exactly Second gear speed

Let out clutch System is all locked up in Second.

This is double-clutching. It INCORPORATES rev-matching, or there is no point in doing it. Therefore, in my opinion, there is no reason to have to say "rev-matching" to describe this process. The rev-matching is the tricky part. How high do you rev it? Experience is the only teacher.

Does double-clutching do any good if you have a synchromesh box? Yes, it makes the synchros work less hard than they were designed to, so they will last longer. The synchros will make up for any errors.

Can you rev-match the layshaft without double-clutching? Yes. Don't use the clutch at all:


Ease the throttle Takes the load out of the system

Select Neutral Layshaft equals engine speed

Blip throttle Engine and layshaft speed up to Second gear speed

Select Second No GRAUNCH if you have the speeds right

This works exactly the same in a synchromesh box as a crash box. Since the layshaft is always connected to the engine, synchros will NOT help you. In fact, I think errors in this method can wreak your synchros. Normally, synchros only have to deal with the rotating mass of the layshaft. Now you are asking them to deal with your whole engine. They ain't gonna like it. You have to be perfect. This is what Rick Mears and many other disgustingly able drivers do. I couldn't do it on a bet.

Can you rev-match the layshaft to the transmission gears by throttle - blipping with regular single clutching? No. The layshaft is not connected to the engine while the clutch is in. Those that recommend throttle-blipping rev-matching are right that it gives a smooth transition when they let the clutch out, but it does absolutely nothing to match the layshaft and does not save your synchros any work at all. (See the way to get around this in autocrossing below.)

OK, here is the hard part. Racing. You are NEVER loafing along in Third gear. The scenario for double-clutching changes: You are blasting along in Third gear and want to change to Second gear for the exit of the corner you are approaching. When you put in the clutch and change the gear selector from Third to Neutral, the layshaft is going a particular speed that matched Third gear at the present road speed. When you brake hard for the corner, the layshaft is going some speed that may or not be right for the speed Second gear will be turning when you are ready to use it. Classic driving style is to double-clutch into Second while braking. This requires heel-and-toe to blip the throttle to rev-match the layshaft. The only reason that this is the "classic" method is because they used the engine braking in Second to help out their lousy brakes.

So here we come to the in my opinion part, where I tell you why I think all the above work is not necessary. In autocrossing with modern brakes, engine braking is counterproductive to slow down for a corner. It upsets your brake balance and does not really help very much in slowing the car down. So instead of revving the engine way up to make Second while you are still going fast, wait to select Second until you are going the entry speed for the corner. The synchros iron out the small difference between the layshaft and Second gear. So instead of revving the engine way up to make Second while you are still going fast, wait to select Second until you are going the entry speed for the corner. The synchros iron out the small difference between the layshaft and Second gear.


Push in clutch and brake together Layshaft equals Third gear speed,
coasts down a bit
Select Second near end of braking The car has slowed, layshaft
coasts while you are still braking, gears
are slowing, no need to hang about in
Neutral. No GRAUNCH, the speeds are
close and the synchros work.
Off brakes and on throttle Here is where you do the rev matching so
that there is no big jerk when you let
out the clutch
Let out clutch It is still well before the (late) apex.
Add power Well, this what you came here for. Go!
Mind the attitude and unwind the wheel.
Let out clutch It is still well before the (late) apex.
Add power Well, this what you came here for. Go!
Mind the attitude and unwind the wheel.

You will note that the actual downshift is one move, and each foot has only one job to do. I am convinced that this method is the second-fastest way to do this. Rick Mears will be able to do the left-foot-brake, no-clutch method faster, due to the lack of transfer time of the right foot from brake to throttle. But since most of us cannot pull that off at all, I think my method is the fastest for non-gifted mortals. I always say to make the synchros work for a living, but if you don't shift too soon, they don't work very hard.

This works very well with a streetable car having a normal flywheel and synchros in an autocross situation. The reason it will not work as well in road racing is that the braking time is longer. A light flywheel that allows the engine to rev down faster is not going to help either.

For the other bit of confusion:

Left-foot Braking = Using your left foot on the brake instead of your right. Sometimes this is done in conjunction with clutch-less shifting. It is not the same as trail braking. I used to left-foot brake (in a straight line) autocrossing the Midget, as long as I did not have to shift. In the Sonett, I often found that I could adjust the attitude in sweepers by stabbing the brake with my left foot while on the power with the right. Such strategies are probably not in the cards for the Europa due to the steering column running between the clutch and brake pedals.

Trail Braking = Braking while turning. Done to unload the rears and transfer weight to the fronts to minimize understeer or cause oversteer. It can be done with either foot. Generally done in FWD cars while entering a turn. Also can be done to delay braking as long as possible at the end of an important straight, in conjunction with an early apex. Be sure you have runoff room if you do this. If you screw up, you will buy some cones, just make sure there is nothing harder to hit.

Left-foot braking and trail braking are not synonymous, but are often done concurrently.

 

another cool little thesis to add to the thread for any interested, primarily about left-foot braking and clutchless shifting. comes from Steve Hoelscher, 4 time DSP champion in an X1/9.

original post

 

All the heel-toe that I do is accompanied by double-declutching. As has been mentioned this is important in disconnecting the layshaft speed to the transmission gears when you need to and saving syncromesh wear. This is the way I've always done it, and it's smooth, and fast.

What I described IS heel-toe, but with double-declutch rev matching. It is the preferred technique if you can pull it off.

 

I agree with everything Steve says. Many times and many cars I have perfected the left foot braking and clutchless shifting. It is not the easy on some cars, and its not worth the extra wear if you can't get it down. But on my car and many others that I drive, it is a simple process. Hell, I even did it in Darth's 550 in Monterey, without him even knowing it was happening. It is all about matching rpms. Once you learn that, you can start moving to the head of the class. Just don't overdrive yourself.

As well, even though everyone keeps saying Ball of the foot, I never use the ball. I use the toes/pad of the foot, on the brake and the ball/side of the heel to match RPMS with the gas. This is how I learned and have tried otherways to do it and it is hard for me to pick up. Once again, do not overdrive yourself. Learn more about braking in a straight line at the threshold and learning the difference between entry speed and exit speed corners. Other things will then fall into place.

Just my thoughts.

 

If your cars transmission has synchros you don't need to double clutch it for the down shift. If it doesn't have synchros than this is a must, or you won't be able to catch the lower gear. Transmissions without synchros were used in racing because the upshifts were much faster than transmissions with. You don't need to double clutch a modern transmission when downshifting. The synchros do the job of matching the next gear for you. Also, the point of reving the engine to catch the next gear is to reduce engine braking which may cause wheel lock, or just inconsistent braking, something you don't want when you're racing on a track.

 

This comes up every now and then, and I guess I just don't get the point of it in a synchro'd car.

 

IMHO, with modern brakes (even not-so-modern) if you are using all the braking available, you cannot downshift more than probably one gear in the time from initial brake application and the release point--watch in-car videos of some good road racers and see what I mean. There is no reason to go 5-4-3-2 when it takes longer and uses more energy than just going 5-2 under max braking. As for using the clutch, if you know your car, you can shift faster without using the clutch--especially with straight-cut gears like you find in a racing gearbox (Hewland, etc). Plus, your friends will be amazed when you perfect the technique...it is supposed to be impossible to do.

 

I can do it the rx-8 at speed but only for gears 2 3 and 4. 5 and 6 don't want to engage.

1 only seems to engage @ 3700'ish rpm's without the clutch. After that I hear expensive, grinding sounds.

 

buy a tough old junker for $200 bucks and do some "experimental" autoX in it. if it dies you've lost bugger all but probly learnt a bit. actually, might have to do that myself before my real car goes back on the road...

 

i'm certainly no gearbox expert, but i wouldn't be selecting 1st gear with OR without the clutch at anything more than 2mph.

 

Yes, almost any car can be shifted this way--and it sure is handy to know how to do if you lose your clutch. Of course, from a standing start you will need someone to push a little to get enough speed to get everything to mesh, but after that, just don't stop for any reason until you get home or the race is over! Power shifting is a little tricky because you still need to pick exactly the right time/speed to drop it into the next gear. As for gearbox damage, we always think we are "grinding the gears", but what we really are grinding are the "face dogs" that actually mesh when we engage a particular gear. The "gears" themselves are continually engaged to their corresponding gear--one on the mainshaft and one on the "output" shaft. The "face dogs" are incredibly hard and are almost unbreakable--but the corners of the faces can wear from "grinding the gears" and then when too much wear happens that "gear" won't stay engaged, and the car will "pop" out of gear. Thus, if you get good enough at slipping the shifter into the next gear at just the right combination of engine speed and road speed, there is no grinding or wear, and the "consumable" clutch disc takes no wear either. However, compared to rebuilding a gearbox or replacing the "face dogs" (or regrinding and re-hardening them), periodically replacing the clutch looks like a pretty reasonable option!!!

 

In the cart, I never use the clutch, other than to start. Same deal on the bike, except sometimes when pressed, I'd use the clutch on the way down, never on the way up. Now they've got electronics for that.

If your car is relatively new, there is no reason to heel and toe on the way down, the factory install syncros for that. However, the F1 does it for you, which is amazing, but probably is why it takes so long to change gears.

Art