Ah, heel-toe downshifting. One of the biggest misnomers in motorsport. You would be forgiven for thinking that this name has something to do with the heel of your foot, something to do with your toe, and somehow they help you downshift. You’d be on the right track, but off by a few centimeters.
Heel and toe downshifting is a technique that I first discovered watching racing videos, where a picture-in-picture video would show one camera pointed at the pedals, while the main image showed the interior or road-viewing angle as the car raced along.
Rev Matching
The main purpose of a heel-toe downshift is to add a braking element to a rev-matched downshift. In order to talk about heel-toe downshifting, let’s do a quick recap on rev-matching. A rev-matched downshift is performed by blipping (with a quick, sharp tap) the throttle while downshifting, from say 4th gear to 3rd to increase the engine speed up from, say, 3000 RPM to 5000 RPM. The result is that when you let go of the clutch to complete the shift, the RPM’s are already up high where they should land when you engage the clutch.
A major benefit of this is that the clutch does not have to do the hard (i.e. friction material wearing) work of bringing up the revs. An added benefit is that the vehicle is more stable while performing the downshift, since the grip at the driven-wheels is not a factor in raising up the engine speed. Yes, that’s right, if you don’t rev-match on a downshift, the traction available at your tires is a factor in the speed of the downshift. This means that if there is not much traction/grip available when you engage the clutch, your tires could slip since the clamping force available at the clutch exceeds the grip available at the road/tire interface.
Sample Scenario
This is not too big a deal if you’re downshifting in a straight line on a level surface. However, if you are driving down a mountain taking a turn at 45mph in 3rd gear and you decide for some reason to downshift (without rev matching) to 2nd, and there just happens to be a patch of unmelted black ice on the road under your driven wheel from that snowstorm last weekend, you will most likely lose traction and, in the case of a rear-wheel drive car without traction control, oversteer suddenly becomes imminent.
A properly rev-matched downshift in this instance, should be a much more pleasant experience, since the engine does rev up, but because of the intentional throttle blip, not because of the sudden increase of the engine speed resulting from engaging the clutch. Of course, ‘sudden’ depends on how much you ‘ride’ the clutch while engaging it. I don’t know about you but I don’t want to be riding (or feathering) the clutch to achieve a downshift while driving down a mountain. I would much rather manually rev the engine and “dump” the clutch while the engine speed is nearly perfectly matched for the next gear, rather than not rev-match and ride the clutch to smoothen out the gear change. Riding the clutch or simply not-rev matching while downshifting causes excessive and premature wear to the clutch friction plates. Downshifting definitely sounds cool when you’re slowing down. Be even cooler than that and rev-match so you don’t wear out your clutch while doing so.
On to Heel-Toe
Now that we’ve covered rev-matching, let’s take it a step further and add the braking element. Let’s jump back to the example on the mountain. You initially wanted to downshift to slow the car down, but since that’s hard on the clutch, you decided to rev-match instead, but now you’re spending precious seconds that could be used to press the brake pedal, to press the accelerator pedal in order to blip the throttle.
If only there was a way you could do both! With heel-toe downshifting, yes you can! By using the ball of your foot to press the brake pedal, you allow the side (lateral plantar?) of your foot enough leverage to lean over and blip the throttle, all while maintaining consistent braking pressure! This means, you can slow down with the brakes, while simultaneously maximizing the engine-braking torque by keeping the engine revs high while downshifting.
As you can see, it’s much less heel-toe and much more ‘ball’-‘medial-plantar’.
Naturally, there is some muscle-memory development needed to execute this movement. However, it’s not as bad as it sounds. All you really need is a set of pedals that are positioned appropriately for YOUR feet.
Stay tuned for how I modified pedals to make heel-toe easier for me.
Happy downshifting!
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