Heel And Toe Downshifting
Heel and toe downshifting is a basic high performance driving technique. While it is not required for street driving, it is nonetheless useful on the street. On the track, it is indispensable. It takes a fair amount of practice to master; for cost and safety reasons you should practice it on the street and only try it on the track when you are comfortable executing it.
There are several benefits associated with heel-toe. For track driving, the biggest benefit is that with heel-toe, braking and shifting can be completely decoupled. Braking can be performed without regard for the gear the car is in, or which gear it needs to be at corner entry, and downshifting can be performed while braking. A second benefit is downshifting can be accomplished quicker. Finally, heel-toe reduces transmission wear.
The same benefits apply to street driving but in reversed order. The biggest priority is likely reducing transmission wear, then shifting faster and finally being able to brake and shift independently.
Heel-toe is a classic example of something "easier said than done". In a braking zone, position your right foot over the brake pedal and the gas pedal at the same time. To achieve this, angle your foot at about 45 degrees with the big toe over the right edge of the brake pedal and the heel over the left edge of the gas pedal. Use the toe to apply pressure on the brake pedal while keeping your toe off the gas. When ready to downshift, press the clutch pedal and use the heel of the right foot to blip the throttle while maintaining constant brake pedal pressure with the toe of the same foot. Shift into the desired gear and release the clutch.
That sounded like a handful, and it is. There are plenty of ways to learn heel-toe - I will describe how I learned it. The way I did it was I learned rev matching, double clutching and heel-toe all at the same time. To follow my recipe you will need a straight piece of road that is sufficiently long to hit about 50 mph safely and hold that speed for at least 15 seconds or so. We will start with a 4-3 downshift as I found it the easiest one to do, but you can try other gears as well.
First, we are going to learn rev matching. Get up to speed where you are doing around 3500 rpm in 3rd gear. Press the clutch, release gas and let the engine drop to idle. Now with your right foot, press and release the gas pedal (this is called "blipping the throttle") in such a way as to hit about 4000 rpm. When the engine is at the highest rpm, 4000 in this case, release the clutch pedal. If you timed it right by the time the clutch engages the revs should drop to 3500 rpm and the car will not jerk as the clutch is released.
I found that over-revving a bit and letting the revs be just over what is needed was a lot smoother than under-revving and asking the engine to speed up as clutch was released. Try to develop awareness of whether the car is jerking from excessive or insufficient rpms at clutch release time - you should feel the difference between being pushed back into the seat and pulled forward towards the steering wheel.
That is a basic rev match. Now try a double clutched version: at 3500 rpm in 3rd gear, press the clutch, shift into neutral and release the clutch. Let the engine drop to idle. Blip the throttle to 4000 rpm - you are doing this while the car is in neutral. When the engine hits 4000 rpm press the clutch, shift into 3rd and release the clutch. When done correctly this again should be perfectly smooth with no jerking of the car.
When you are doing the double clutched version you will find that the time between blipping the throttle in neutral and releasing the clutch for the second time is very small, in most cars it should be 1 second or less. If you wait any longer the rpms will drop too much and the car will jerk. Work on committing the timing that results in smooth clutch engagement to your muscle memory.
You can now perform a double clutched, rev matched downshift from any gear to any gear. Trying 4-3 downshift, start in 4th at 3000 rpm. Press the clutch and shift to neutral. Release the clutch. Let the engine drop to idle. Blip throttle to 4000 rpm, press the clutch again, shit into 3rd and release the clutch. If you mastered the 3-3 double clutch exercise, doing an actual 4-3 downshift should be a piece of cake.
Now it is time to add braking to the mix. Angle your right foot at about 45 degrees left until you can press both brake and gas pedals without moving your leg. Start over from the 3-3 exercise, continuing to 4-3 double clutched downshift, maintaining that right foot position. You will now be pressing the gas pedal with the right edge of your right shoe instead of with the entire foot. The correct movement is rolling (rotating) your right foot about its big toe - thus keeping the big toe still over the brake pedal. You can also rotate your right foot about its center axis, therefore moving your big toe upward as your heel moves downward, but this will compromise your braking later thus try to avoid doing it. Note that you are not applying any brake pedal pressure yet.
After you are comfortable downshifting with your right foot covering the brake pedal it is time to apply the brakes. If you've been following along, this simply requires you to move your foot slightly so that you are pressing on the brake pedal a bit. As you do this you will decelerate the car - therefore you will need to either go faster in the higher gear or blip throttle to a lower engine speed in the lower gear to compensate for the braking. You can either start with a 3-3 exercise while braking or directly with 4-3 downshift while braking.
Next, apply more brake pressure - brake harder. You will now start to find rpms too low in 3rd. You might try a 3-2 or 4-2 downshift. If your timing is off go back to simple rev-match exercises for 2-2, 3-2 and 4-2 shifts.
As you brake harder, pay attention to whether you are holding constant brake pedal pressure when you are blipping the throttle. Chances are, you are not. This is easier to notice when you are applying significant braking, for example, in a 4-2 downshift. You want the brake pressure to be constant through the entire process.
Tagged: novice, intermediate