Heel & Toe

[macdaddy]

Please forgive my daftness.

A lifelong motorsport fan, "Heel & Toe" is a term that I've heard used countless times. And as embarassing as it is to admit, I don't really understand what it means.

Would anybody be so kind as to educate me a little?
Thanx.

[Al Weyman]

As far as I have always been aware it is giving the throttle a blip as you are downshifting into a braking area with your right foot while braking at the same time (also with the right foot of course), The idea is it gets the engine revs up to meet the lower selected gear ratio and if done right (espeicially in my old Muncie truck grade gearbox in my chevy) you get a smoother more positive downchange.

[graeme]

The confusing thing is that you don't use your heel (may be it did in the 1930s...) - left side part of your right foot on the brake and tilt the right side of your foot on the accelerator on down shifts. Matching revs for the new gear (hopefully) prevents the wheels doing 40mph and the drivetrain doing the equivalent of 60mph, which gives a momentary lock-up on the driven wheels (picting you into a wall...).

[Chris Y]

The phrase 'heel & toe' is often a little misleading. Sometimes it really should be called 'ball and edge' (although that's open to interpretation in other ways ), because a lot of the time you use the ball of your foot (just below your big toe) to brake, and the far right edge of your foot to blip the throttle to match the revs. Of course, it depends on your pedal setup. I think with a lot of the US cars, the accelerator pedal is flatter and much lower than the brake, which is quite different to European/UK cars, so 'heel and toe' might be more appropriate over there

As well as achieving smoother gear changes, it also helps stop you locking your rears (in the case of rear-wheel-drive) under heavy braking and downshifting. As the back-end is light (a lot of the weight is transferred to the front), when you downshift, if you don't match the revs, then the engine braking effect can make the rear wheels snatch and lock.

[dtype38]

I was watching some in-car footage from the late 90's BTCC and caugth a shot down into the footwell of Jan Lammers driving a Volvo 850. It was the first time I'd actuall seen a proper "heel & toe" with the ball of his right foot firmly on the middle of the brake pedal and his foot at nearly 90 degrees, blipping the throttle with his heel! Not only that, as soon as he was into the corner, he swapped to left foot braking to balance the car in the corner, then some clutchless upshifts before back to heel & toe'ing the down shifts again.... I think the commentator said something about "dancing" on the pedals. :-)

[Al Weyman]

Bet he could'nt do that with a GM Muncie tank box :-)

[dtype38]

Originally Posted by Al Weyman

Bet he could'nt do that with a GM Muncie tank box :-)

Why, pray tell, did you put a gearbox from a tank into your racing car? I think what you're doing is called double-declutching, not toe-and-heeling

[Al Weyman]

Cause thats what GM decided to stick in it and thats what the rules say I must use!

Actually it is a very stout box with very close ratios and long 1st gear (almost too long) and is actually used in their trucks (not tanks I made that up although you never know) I believe (wide ratio version of course). Only problem is you have to be a bit heavy with them. A smooth change it ain't.

[dtype38]

My sympathies... I just got rid of a very clunky change myself.

[midgetman]

>>>>>>>>I think what you're doing is called double-declutching, not toe-and-heeling

Same thing! Is not heel-and-toeing merely double-declutching without releasing the brake?

[dtype38]

Dunno?? I thought toe & heal was to bring the engine revs up to match the road wheels in a lower gear so there was no snatch when you let the clutch out, but that double-declutch was letting the clutch out in neutral during the shift to bring the input shaft in the box up to the same speed as the output shaft so that the gear could be changed without damaging the teeth on a non-sychromesh gearbox. But I may be wrong... it won't be the first time :-)

[Tim Falce]

Originally Posted by midgetman

>>>>>>>>I think what you're doing is called double-declutching, not toe-and-heeling

Same thing! Is not heel-and-toeing merely double-declutching without releasing the brake?

Double de-clutching you have to let the clutch up while in neutral to match the gearbox revs to the engine.
Ah the joys of a Scammel gate change or Fuller roadrunner box

[Al Weyman]

You are right D-Type, I used to work for a company many years ago that actually became MFI but this was the vehicle division and they used to by ex-military vehicles. Anyhow some of those old trucks you had to double de-clutch as you describe or you could not change gear one in particular if memory serves me was the Austin K series truck, horrible thing to drive and there was a Comma the same.

[Mackmot]

http://www.hewland.com/svga/help.htm

[midgetman]

I sit corrected. Kinda. I tend to double-declutch with the MG, hence the comment. Thought the two went together.

Thinking about it, when I drove a truck I used to drive virtually clutchless, up and down, and you could feel the good a blip on the throttle did, you could feel the torque coming off and the cogs sliding into place. Never had to use crash boxes though - "Eee tha modern drivers, tha don't know tha's born".

[Cameron Winton]

I always thought that Heel & Toe came from the days of crash gearboxes & poor brakes. You needed to blip the throttle in neutral on down changes to synchronise engine speed to road speed while braking. Two reasons for this. 1. No synchromesh so you need to manually synchronise. 2. You need the engine braking to slow the car down so simultaneous down changes & brakes were essential.
I learnt both when I was younger as I was competing with a midget (crash 1st) and now use it all the time if the pedals are in the right position. Force of habit. Does help in smoothing out the down changes but I will stop doing it if I find I can go faster without.
I have never opened up any of my gearboxes myself but the family Mondeo must have the best looking synchro's ever seen at 80k miles!

[SpawnyWhippet]

The most important part of a heel and toe change was mentioned by graeme, ie to prevent the rears locking and sending you into a spin under heavy braking. The blip gives higher engine revs so when you select the lower gear, it prevents the sudden deceleration of the rear wheels hence losing grip and spinning the car (imagine pulling the handbrake whilst flying into a very fast corner.) Double de-clutching is not the same thing.

[Al Weyman]

Very good point Andy about locking the rears in fact I did just that when fluffing the down changes in my nose heavy Camaro at Pembrey hatchetts the other week but as it was my first race for 8 years was to be expected I guess, you have to work at getting it right,

[midgetman]

>>>>>>>you have to work at getting it right

Or you become an F1 driver where the software does it for you ;-)

[Walshy]

There is another advantage to Heel'n'Toe!

It helps keep the engine on Cam, hence better drive out of the corner. You know in your road car how when you down shift, you get that deceleration in your engine? Well, by "blipping" the throttle it keeps the revs up and on cam, so making the exit of the corner quicker. As most of you who race will know, letting the engine revs die in your race car gives the same effect as moving away from a set of traffic lights in 3rd gear in your road car............

[StephenRae]

I don't think thats right Chris, it doesn't matter how much you rev in between gearchanges when you let the clutch out the engine speed can only match the road speed. Blipping the throttle does save the clutch and geartrain, but if you change down later, after slowing down, it hardly matters.

[Walshy]

I know what your saying Steve, but it does help against "lazy gear change". ie. The hairpin at Anglesey is somewhere that is very easy to let the engine get off cam, but with heel'n'toe, it does help with better drive off the corner.

But then I suppose a lot of that also depends on when you downshift. If you use the downshift to slow the car, then it won't work, but if you use the brakes and then downshift last minute, by time you've changed and come off the clutch, with the revs on cam, you are straight back on the throttle............rather than trailing it as some do into corners.

[Chris Y]

Originally Posted by StephenRae

...when you let the clutch out the engine speed can only match the road speed

Unless you have a dodgy clutch

[StephenRae]

Originally Posted by Chris Y

Unless you have a dodgy clutch

Good point! If I was planting it on pole I could speak with more authority...anyway I think slowing down with the brakes only is better and then then missing out the inbetween gears and shoving it into the gear you want seems to work! I don't seem twear out clutch rings...so far

[Dutch chap]

Have a look at this: http://homepage.mac.com/gkawano/heel%20and%20toe.mov

The first action is heel-and-toe downshifting and the second is double clutching.