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04-02-2007, 12:32 PM
michael lang wrote:
It does not allow you to go deeper into a corner. It can throw off the balance of the car.
1st part- The imaginary braking zone is about 300 feet. You apply the brakes and maintain steady pedal pressure and after 300 feet you're at the proper speed to go around the following corner. While you're braking you need to downshift the car so that when you apply the throttle in order to exit the corner you're in the proper gear to get the best acceleration you can. So that said you have 300 feet in which to get all your downshifting completed. You can skip gears or not. If you choose to skip gears you have to wait untill you're later into the braking zone and slowed down more before downshifting. Bob made a great point by recommending to just keep your hand on the wheel until you have slowed the car enough. Doing it either way correctly and with precision does not change the length of the braking zone but.... If you're going down 5-4-3-2 and your brake pedal pressure reduces slightly with each throttle blip you're now going to need more time to slow the car. You're now lengthening the braking zone meaning you will have to start your braking sooner. This is slower. I believe this is exactly what Bob means when he talks about threshold braking and the control required while you're heel and toe downshifting.
Braking deeper into a corner as you know is "trailbraking" and that can be done AFTER using either downshifting technique. All of your shifting should be done before turn in and no shifting should take place after turn in while you're trailbraking (it will happen but it shouldn't and this will be how you look >
hock: when you do it!)
2nd part - What you're trying to do is use all the available grip of the tires as efficiently as possible. If you're doing anything that upsets the balance of the car you will be slow at best and at worst you will crash alot. If you are skipping gears and you are doing it too early in the brake zone still carrying too much speed to be in the lower gear you're selecting or just not blipping to a high enough engine rpm you will get "engine braking". It's when you hear the engine rev when someone let's out the clutch after they downshift. This is slowing the car. It's using some of the tires available grip to do that. If you're threshold braking and you downshift too early you will lock up the rear tires because they have no more grip available. Also if you do it too late and too abruptly let's say after turn in you will likely lock the rear tires and spin the car especially in your 911. The front tires are loaded by the brakes mostly and it's going to be rear tire grip that will be compromised by a less than smooth downshifting technique.
In the end it's best to do what's most comfortable for you. How deep you go into the brake zone should be the very last thing you worry about. I would work on your speed and traction sensing skills. Making sure the car is on the correct line and deeply "feel" what the car is doing, where it has traction and where you can add more throttle. The reason I say this is that late, deep braking usually requires a transition from full threshold braking to throttle modulation in a very short time window. Unless your other skills are honed properly you can actually be slower as all you're doing after the brake zone is fighting for control of the car instead of being smooth, picking up the throttle early and going faster.
Quote:I understand the footwork part and understand that no one is racing, that being said, does skipping gears on the downshift allow a driver to dive deeper into the turn than not skipping gears? And if so, doesn't it throw off the weight balance with loading up the front end so heavily?
It does not allow you to go deeper into a corner. It can throw off the balance of the car.
1st part- The imaginary braking zone is about 300 feet. You apply the brakes and maintain steady pedal pressure and after 300 feet you're at the proper speed to go around the following corner. While you're braking you need to downshift the car so that when you apply the throttle in order to exit the corner you're in the proper gear to get the best acceleration you can. So that said you have 300 feet in which to get all your downshifting completed. You can skip gears or not. If you choose to skip gears you have to wait untill you're later into the braking zone and slowed down more before downshifting. Bob made a great point by recommending to just keep your hand on the wheel until you have slowed the car enough. Doing it either way correctly and with precision does not change the length of the braking zone but.... If you're going down 5-4-3-2 and your brake pedal pressure reduces slightly with each throttle blip you're now going to need more time to slow the car. You're now lengthening the braking zone meaning you will have to start your braking sooner. This is slower. I believe this is exactly what Bob means when he talks about threshold braking and the control required while you're heel and toe downshifting.
Braking deeper into a corner as you know is "trailbraking" and that can be done AFTER using either downshifting technique. All of your shifting should be done before turn in and no shifting should take place after turn in while you're trailbraking (it will happen but it shouldn't and this will be how you look >
hock: when you do it!) 2nd part - What you're trying to do is use all the available grip of the tires as efficiently as possible. If you're doing anything that upsets the balance of the car you will be slow at best and at worst you will crash alot. If you are skipping gears and you are doing it too early in the brake zone still carrying too much speed to be in the lower gear you're selecting or just not blipping to a high enough engine rpm you will get "engine braking". It's when you hear the engine rev when someone let's out the clutch after they downshift. This is slowing the car. It's using some of the tires available grip to do that. If you're threshold braking and you downshift too early you will lock up the rear tires because they have no more grip available. Also if you do it too late and too abruptly let's say after turn in you will likely lock the rear tires and spin the car especially in your 911. The front tires are loaded by the brakes mostly and it's going to be rear tire grip that will be compromised by a less than smooth downshifting technique.
In the end it's best to do what's most comfortable for you. How deep you go into the brake zone should be the very last thing you worry about. I would work on your speed and traction sensing skills. Making sure the car is on the correct line and deeply "feel" what the car is doing, where it has traction and where you can add more throttle. The reason I say this is that late, deep braking usually requires a transition from full threshold braking to throttle modulation in a very short time window. Unless your other skills are honed properly you can actually be slower as all you're doing after the brake zone is fighting for control of the car instead of being smooth, picking up the throttle early and going faster.