Why heel-toe downshift? When you are racing a car - or driving it within the higher RPM range during spirited jaunts - downshifting to a lower gear causes a mismatch between engine speed and wheel speed. The engine is spinning at X RPM's, and the driven wheels are spinning at Y RPM's. That X/Y difference in RPM's causes two things:
This scenario is not a big deal on a heavy aircraft carrying so much momentum that will not even flinch from the brief moment of traction loss. On a lightweight automobile however, the loss of traction in the driven wheels (specifically rear wheels) can cause the car to become unsettled, especially if traveling into a corner with a great deal of momentum and side-load (cornering load), on the brakes heavy, and presumably with no more available traction to spare (Remember the "traction circle"? This is another post's subject matter if you are not familiar!). Barring a lesson in physics, you can probably assume how weight transfer works in terms of automobiles:
It's probably obvious now to you why matching engine RPM's with wheel speed (aka: heel-toe downshifting) is so important when racing, and why our Accel Grip pedal can be so beneficial to those who desire to practice this art. I call it an "art" because it's not something that comes naturally when driving, and most certainly is not something you would ever need to practice in your everyday driving routine, so just like any "secondary" technique that is not subconscious in nature (i.e.: bouncing a ball while walking), it must be practiced until it is subconscious, which means that you "don't have to think about performing the action, you just do it automatically". And as with any "art", the more one practices, the better they get at it. In essence, Heel-Toe Downshifting is the art of "hitting the ground with your feet running" as to provide a smooth transition between the gear you were in, and the gear you need to be in, coming through - and out of - the corner.
So now that you know why you should heel-toe downshift, how does one do it? Here are my recommended steps in practicing heel-toe downshifting:
It should be clear to you that the tilt method is way more controlled and precise than the original method. If it's not and the original method is more natural and comfortable, by all means go with it! As I said above, there is no "right way" to perform heel-toe downshifts; the only thing that matters is that you find a comfortable - and consistent - method of doing it. You'll find that the more you practice, the more subconscious the action will be, leading up to it becoming a natural reflex and not something you need to think about. After a few weeks of daily driving and practicing heel-toe on EVERY downshift I made, it was something (and still is something) I automatically do every time I downshift a manual transmission car. My brain is programmed to do it, which is what you should be trying to achieve as a race driver, or simply as an educated "extracurricular" driver that enjoys advanced driving techniques and that spirited jaunt through the interstate cloverleaf or mountain back road. If you find yourself on the racetrack one day, it is one less technique among many needed to wheel a car consistently around a racetrack lap after lap. And with consistency comes speed as they say!
Here are some examples of heel-toe downshifting. These are great examples to visualize my explanations, and they prove that no technique is "wrong", and what matters most is you find the method that works for you and is smooth. See if you can spot the differences between the techniques and which looks easiest/difficult:
Some of my favorite "pedal cams" come from the Australian V8 Supercars of Australia:
Here's a good look at the amount of heel swing with the original technique in a British Touring Car:
Not all Aussie V8 guys use the original technique! Here's a fantastic example of my "tilt" method used in an Australian V8 Supercar:
And who better to provide an example of my "tilt" technique than the legend himself Ayrton Senna? Expensive Italian loafers and all!
As a bonus, here's an interesting look at a super advanced technique: left foot braking (it's a sequential shift transmission with no clutch required):
Once I can get some video, I'll post my heel-toe technique using our Accel Grip Pedal in our Miata.
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