The Purpose and Benefits of Heel Toe Down Shifting
HT shifting is a braking and shifting method allowing you to downshift quickly and safely, during constant braking, without upsetting the balance of the car. Good HT shifting keeps the engine, transmission, and rear wheel speeds matched closely so there is no jerkiness through the drive train when down shifting, making high speed maneuvers much more safe and stable. Smoothness is a key to going fast safely so this skill is a must if you want to drive fast with a high degree of control where braking and downshifting is involved. It also puts a lot less stress on the whole drive train, making it last a lot longer.
Maybe another way to look at this is to consider what happens when you don’t HT. You are coming up to a turn, going fast. It’s obvious that you have to slow down in order to get around the corner, on the pavement at least :>) You are braking now but must also get into a lower gear to accelerate quickly out of the turn. When you shift into the lower gear while braking and let out the clutch, a major jerk goes through your car’s drive train while your rear wheels are chirping, or worse, locking up. That will definitely put a serious pucker in your hinder parts!!!. You might get through corner in one piece. It wasn’t smooth and controlled, therefore slow and dangerous, and your car just took a beating. Not a lot of fun for you, the drivers around you or your car.
Now consider the same scenario when you can HT. You come up to the same corner. You begin braking to slow down with your right foot on the brake. Subsequent to beginning to brake you need to downshift to be able to exit the corner under power in the right gear but you don’t want to stop your braking at that time. While pressing the brake you are about to depress the clutch with your left foot. Up to this point, you have done nothing differently but now the fun begins. With your right foot still fully planted on the brake and as you depress the clutch, you simultaneously blip the gas pedal with the right side of your right foot. The engine revs up, matching the speed of the gears in the transmission and rear wheels. When you let out the clutch after down shifting, everything engages smoothly, you get back on the go pedal, smoothly accelerating out the turn to your track out point. Your car’s balance and stability were never disrupted, you were smooth, fast and your car is just as happy as it was before you went through the corner. It also puts a smile on your face because you know you just completed a tricky high speed maneuver safely and very quickly. You will NEVER be as fast or smooth as you can be without learning this crucial skill.
http://www.crossedflags.com/nuke/htm...article&sid=10
