Can someone explain why "heel & toe"

[Alan L]

+1+1+1
The sound of a good downshift is hard to beat. Quickly followed by another, and another. Ooooh.
Alan

[Synchro Joe]

Hurley Haywood and Motoman heel and toe session in GT3:
https://www.youtube.com/watch?v=YqYeusE8ksk

[fastricky]

OK I've dabbled with H&T here and there and have never found a true need for it (I'm strictly a road motorist, not a track driver). As far as I understand the most important element of H&T is to rev match to keep the car's momentum from hiccuping when you release the clutch during a downshift. Here's my technique that ASAIK achieves the same result, what am I not understanding?

1. Brake
2. While continuing to brake engage clutch and shift into lower gear
3. Get off of the brake and hit the accelerator to roughly rev match
4. Then release clutch and accelerate further

To me the wasted time/element of H&T is that you 1. Brake 2. Clutch and downshift 3. Blip the throttle to rev match while staying on the brake 4. Release clutch 5. Pivot your foot back to be fully on the accelerator and then hit the gas.

Seems like a slower (more steps involved) process than my technique because after the H&T blip rather than fully hitting the gas you then are still partially on the brake and need to pivot your foot to be on the gas. Clearly I'm missing something so help me out.

[icarp]

Tom and I made this video to help with the understanding of the benefits for implementing the heal and toe double clutch process

https://www.youtube.com/watch?v=0TYD4aOvN80

Ian

[winders]

Sigh....

[Reiver]

Before synchro box's existed one had to match revs to shift gears efficiently...also. On the earliest cars and even up into the 40's many vehicles came with the accelerator in the middle and the brake right/clutch left. GP driver from the 1950's, Mike Hawthorn, always asked to have his rides set up like that
That is where the term originated as it was very easy to step on the brake with the ball of your foot to the right of the accelerator and touch the accelerator with your heel.
We have simply learned to do the same with a bit of ankle gymnastics with the 'modern' layout.

Heel/Toe work keeps your car balanced when downshifting thru corners.... not moving the point of balance forward violently as a normal downshift would.

Like riding a bike, when you get it you get it.

[stownsen914]

H&T and double clutching / double de-clutching are related of course, but not the same thing.
Rev matching without double clutching does achieve the benefit of reducing momentary locking of the rear wheels upon selecting the lower gear. Not as much of an issue on the street, but on track it can happen frequently under threshold braking. Helps reduce shock to the drivetrain a bit too.
Properly executed double clutching also gets the trans input shaft spinning at more equal speed to the output shaft to ease the engagement of the gear hub and dog/synchro gear. While not necessary, it does further ease the shock and wear on trans parts compared to rev matching, and certainly compared to doing neither.

[fastricky]

Originally Posted by icarp

Tom and I made this video to help with the understanding of the benefits of the heal and toe double clutch process

https://www.youtube.com/watch?v=0TYD4aOvN80

Ian

OK now! That is very helpful, seems that double clutching is the element I didn't understand (balancing the tranny speed). That combined with H&T starts to make sense now to me, thanks!

[fastricky]

Originally Posted by stownsen914

H&T and double clutching / double de-clutching are related of course, but not the same thing.
Rev matching without double clutching does achieve the benefit of reducing momentary locking of the rear wheels upon selecting the lower gear. Not as much of an issue on the street, but on track it can happen frequently under threshold braking. Helps reduce shock to the drivetrain a bit too.
Properly executed double clutching also gets the trans input shaft spinning at more equal speed to the output shaft to ease the engagement of the gear hub and dog/synchro gear. While not necessary, it does further ease the shock and wear on trans parts compared to rev matching, and certainly compared to doing neither.

This is starting to penetrate my slow revving brain, thanks!

[Alan L]

Originally Posted by fastricky

OK I've dabbled with H&T here and there and have never found a true need for it (I'm strictly a road motorist, not a track driver). As far as I understand the most important element of H&T is to rev match to keep the car's momentum from hiccuping when you release the clutch during a downshift. Here's my technique that ASAIK achieves the same result, what am I not understanding?

1. Brake
2. While continuing to brake engage clutch and shift into lower gear
3. Get off of the brake and hit the accelerator to roughly rev match
4. Then release clutch and accelerate further

To me the wasted time/element of H&T is that you 1. Brake 2. Clutch and downshift 3. Blip the throttle to rev match while staying on the brake 4. Release clutch 5. Pivot your foot back to be fully on the accelerator and then hit the gas.

Seems like a slower (more steps involved) process than my technique because after the H&T blip rather than fully hitting the gas you then are still partially on the brake and need to pivot your foot to be on the gas. Clearly I'm missing something so help me out.

I don't like this technique as compared to a H&T blip on throttle. You run the risk of burning your clutch out by getting on the gas before you release the clutch. Bad technique. Blipping the throttle then releasing the clutch means the flywheel is free spinning and can take up the load on the clutch progressively. It is easier on the clutch than a normal downshift.
Alan

[kent olsen]

I've use the 'heel/toe' technique for ever. Also I've never had to replace a clutch. I heel/toe and sometimes double clutch to keep the clutch and engine speed nearly the same. I have replaced a clutch but only if I had the engine out for another reason.

[fastricky]

Originally Posted by Alan L

I don't like this technique as compared to a H&T blip on throttle. You run the risk of burning your clutch out by getting on the gas before you release the clutch. Bad technique. Blipping the throttle then releasing the clutch means the flywheel is free spinning and can take up the load on the clutch progressively. It is easier on the clutch than a normal downshift.
Alan

So if I understand this correctly the advantage of blipping the gas during a H&T versus what I was doing is the clutch is engaging while the power is spooling down versus engaging while the power is being added assuming the clutch engages at equal revs in both instances?

[winders]

The only good reason to doubt-clutch with a 915 is if you want to make the synchros last longer. Or, if you think it is cool. You certainly don't need to do it. There is no performance advantage in doing it. There is a great reason to do rev matching on downshifts which is to prevent a sudden increase in engine braking.

[spuggy]

Originally Posted by fastricky

OK I've dabbled with H&T here and there and have never found a true need for it (I'm strictly a road motorist, not a track driver).

I practiced heel'n'toe in the 944, and would use it often. When I bought the 911, I didn't initially find the pedals conducive to it (and a sloppy 915 was a lot to deal with at the same time), so never used it.

Until one day I was decelerating on the (curved) approach to a roundabout on a semi-greasy country road where the entrance with priority was completely obscured until you were basically almost on the white line and could see down it.

Without any conscious choice, heel'n'toed the shift keeping the weight distribution & braking constant while selecting an appropriate gear for the decision point. And I've used it in the 911 ever since.

If all you use it for is to keep the weight bias the same so the car isn't unsettled by you coming off/reapplying the brakes while downshifting - good enough reason right there, in my book.

Many seem unhappy with the 911 pedals and the way the accelerator tends to be lower than the brake engagement point. I find hanging the ball of the foot off the brake pedal, turning the foot sideways and rocking the foot to blip with the heel works great. Never felt the need to modify or adjust the pedals - as they seem about perfect to me.

I abandoned attempts to left-foot brake long ago though; muscle memory seems to want to drive the left foot down as though it's on the clutch; takes a lot of practice to get past that, it seems...

[winders]

Also, gears are in a constant mesh.....they never crash into each other unless something breaks.

[Jeff Higgins]

Cheap, easy, quick fix for the pedal relationship when using the stock pedals. VW Beetle gas pedal rubber slipped over a piece of wood paneling glued to a piece of plywood and bolted to the stock pedal.

[Qtrfoil]

If we're doing videos, this just shows you're not really a boss unless you can do it in Gucci loafers.

https://www.youtube.com/watch?v=kzLjZWrpzmQ

[Marine Blue]

^^^I was about to post that video too, truly an art form with the feet.

[Qtrfoil]

It's actually the way he feathers the gas that's most interesting to me.

[Locker537]

Originally Posted by fastricky

OK I've dabbled with H&T here and there and have never found a true need for it (I'm strictly a road motorist, not a track driver). As far as I understand the most important element of H&T is to rev match to keep the car's momentum from hiccuping when you release the clutch during a downshift. Here's my technique that ASAIK achieves the same result, what am I not understanding?

1. Brake
2. While continuing to brake engage clutch and shift into lower gear
3. Get off of the brake and hit the accelerator to roughly rev match
4. Then release clutch and accelerate further

To me the wasted time/element of H&T is that you 1. Brake 2. Clutch and downshift 3. Blip the throttle to rev match while staying on the brake 4. Release clutch 5. Pivot your foot back to be fully on the accelerator and then hit the gas.

Seems like a slower (more steps involved) process than my technique because after the H&T blip rather than fully hitting the gas you then are still partially on the brake and need to pivot your foot to be on the gas. Clearly I'm missing something so help me out.

In my opinion, your technique is perfectly fine for the street but it doesn't function well on the track where your braking and cornering forces are much higher.

Heel toe is more faster on track, and will keep the car more balanced as there is less time when the car is not being balanced via brake/throttle. You downshift while still braking.