Trail Braking, Heel and Toe techniques

[Porsche-nine11]

ive heard both of these terms befor ebut have no clue what trail braking is. When is it used? is it in formula one? do they use it nascar, drifting? and what the heck is heel and toe, it sounds like some kind of dance mmove. but all i knwo about it is that you do it when you downshift. are floor hinged pedals more suitable for heel and toe? any answers would really be aprreciated.

[midgetracing28]

There road racing terms so if u dont plan on going fast through paved turns i wouldnt worry about it. heel toe is basically using ur heel on brake with ur toe getting the rpms up so u can put the car back into gear while going through the corner. Its a pain in the ass to me personally i have small feet.

[LVApex]

Originally Posted by midgetracing28

There road racing terms so if u dont plan on going fast through paved turns i wouldnt worry about it. heel toe is basically using ur heel on brake with ur toe getting the rpms up so u can put the car back into gear while going through the corner. Its a pain in the ass to me personally i have small feet.

You have that backwards, Toe on the brake and blip the throttle with your heel. (I acutally roll my foot to blip the throttle rather then use my heel).


Trail brakeing = Extending your brakeing zone in to the 1st quarter of the turn. Couple of reasons to do this would be to Maximize your time on the throttle down the previous straight, and reducing understeer or perhaps instigating a bit of oversteer on corner entry. Down sides would be if you mess it up.... your pretty much going off track or spinning.

Heel toe is just a technique that allows you to down shift and brake at the same time. You "blip" the throttle between gears to equalize the RPM's between the transmission and the engine so you dont end up Upsetting the balance of the car. (it stops that jerkyness when you try to down shift and the car lurches forward).

Heel toe you may use on the street, I know I do. Trail brakeing is only really usefull when your driving 10/10ths I.e. In compitition.

[Porsche-nine11]

so why dont you just engage clutch, put the car in the required gear, and then release the clutch when you need to?

[midgetracing28]

the car is better balanced if there is no drag on the rearend and accelerates quicker if ur ate the right rpms.

[Gohan Ryu]

Originally Posted by LVApex

I acutally roll my foot to blip the throttle rather then use my heel

Funny I do that too - depending on what shoes I'm wearing I usually goose the accelerator with the side/top of my foot.

Originally Posted by Porsche-nine11

so why dont you just engage clutch, put the car in the required gear, and then release the clutch when you need to?

That's exactly what you are doing when you heel-toe. Except at the same time you are doing that you are also braking, rev-matching, and cornering.

I actually learned how to trail-brake by playing Gran Tourismo 4 on my Playstation. I know it's just a game but the techniques are the same. I went to a Jim Hall Kart racing seminar and applied the same techniques that I learned playing the game - my lap times were just a few tenths of a second slower than the instructors.

[LVApex]

Originally Posted by Porsche-nine11

so why dont you just engage clutch, put the car in the required gear, and then release the clutch when you need to?

Because you then upset teh cars balance, typically at the worse time possible... corner entry.

Basically if you dont blip the throttle and equalize the RPM's between the Transmission and the engine, then when you do down shift you get that big jerking feeling and weight gets shifted forward.... causing a momentary reduction of traction at the rear wheels, Which if you are starting a turn at the time, can cause the car to Oversteer. A state that you should strive never to have in your 911.... Unless ofcourse you like going off track while going backwards. (Porsches have wide rear tires for a reason... and it has little to do with how much HP they have)

[Porsche-nine11]

i play gran turismo four as well, and i have the Int. B license, and 9/10ths of the Int. A license, and i never learnt about trail braking. what is it exactly.

[LVApex]

THe Physics of Racing Pt 23: Trail Brakeing. By Brian Beckman, PhD

note: another benifit of Trail brakeing, asside from letting you have a higher corner entry speed, would be to help instigate oversteer or Reduce corner entry understeer.

[Porsche-nine11]

wow, that article was really good. ive read some of those before. that ereally is a good explanation of trail braking. could you post the homepage URL on here so i can add it to my favorites.

[Porsche-nine11]

oh yeah, i have another question. when you blip the throttle in heel and toe, how do you know how much to blip it. is it just a matter of knowing your car. and the reason you have to do that is that the tranny and engine are moving at different speeds, ive realized that now. but which is moving faster, does tranny move faster so you have to increase RPM's to get up to the trannys speed? or is it the other way round. i hope you understand the question.

[LVApex]

Originally Posted by Porsche-nine11

oh yeah, i have another question. when you blip the throttle in heel and toe, how do you know how much to blip it. is it just a matter of knowing your car. and the reason you have to do that is that the tranny and engine are moving at different speeds, ive realized that now. but which is moving faster, does tranny move faster so you have to increase RPM's to get up to the trannys speed? or is it the other way round. i hope you understand the question.

You'll get use to how much you have to blip the throttle with pratice... you'll know you've done it wrong when you "feel" the shift. If you are pushed back in to the seat, like you are accelerating, then you bliped too much. If you are pushed in to your belts, then you blipped too little. A good downshift should be heard and not felt.

as far as engine RPM vs Transmission RPM.... On upshifts, the Transmissing is spinning slower then the engine. On down shifts the engine is spinnig slower then the transmission.