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Do any of you use left foot braking? My driving instructor suggested it would be a good thing to learn so I've been practicing it on the street this week. When do you use it?

Can you describe the exact sequence coming into a left foot braking corner? I mean, I assume you still have to start braking with your right foot so you can rev match your downshifts.

If any of you are experienced with this i'd love to get some help.
 

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You left-foot brake only when you don't need to downshift. Otherwise you brake with the right foot so you can actuate the clutch with your left.
 

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You can minimize some of the weight transfer of switching your right foot off the accelerator and back, when using left foot braking. It also helps negate the coasting area when you are neither accelerating, nor braking (foot not on either pedal). In karting you might be able to use it to keep the revs up.

The exact technique depends on the corner. For example, some corners that require only a lift or a tap of the brake could have you being on the accelerator and the brake at the same time in some proportion. Maybe some lift and a quick tap to settle the car will work. Other corners that require full braking could see you smoothly lifting from the throttle as you squeeze the brakes. As you accelerate out of the corner, it is the reverse.

Have never used this technique in hard driving before because I am not yet able to use my left foot as well as my right, but I'm getting there. This is how I understand it, but maybe I need to wait for Walshy's video before I can fully understand it. :)

Any professionals out there want to take a stab?
 

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I taught myself to left-foot brake on an automatic a long time ago, in order to improve reaction time and to keep the slushbox spun up. Unfortunately, I haven't managed to learn how to left-foot brake when there's a clutch involved. When I try, I find myself doing it when going into corners that require a downshift as well, and the resulting confusion in the pedal box results in me pushing through the corner and dropping out of the power band.

Jim
 

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apkom said:
Not a bad article in explaining the basics, but is incorrect in the parts about maintaining higher engine RPM, unless one is driving an automatic. The turbo part is mostly correct though the reason is that the throttle remains at least partially open all the time keeping the turbo spooled up, not the engine running at a higher RPM (in a stick-shift car).
 

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ChrisB said:
Not a bad article in explaining the basics, but is incorrect in the parts about maintaining higher engine RPM, unless one is driving an automatic. The turbo part is mostly correct though the reason is that the throttle remains at least partially open all the time keeping the turbo spooled up, not the engine running at a higher RPM (in a stick-shift car).
Actually, most of the physics in that article are wrong. The basic premis the author states is that the car doesn't dive (not as much weight transfer) as much if you stay on the gas while braking. This is partially true only because you are producing less braking force because the engine is canceling some of it out. NOT GOOD! You could produce the same affect by just braking less. Well, actually not even less, but smoother, and more progressively rather than just mashing the pedal.

There is no reason in a normal car to make the car and brake work against each other, with the exceptions of turbo automatics, and the rare case where you are your rotors are wet and you lightly drag the brake to dry them before you need to hit the brakes. In standard cars, the engine rpm is directly related to wheel speed (unless your clutch is slipping), so staying on the gas doesn’t help at all.

The point of left foot braking is to reduce that fractional time it takes from moving the right foot from the gas to the brake, but that doesn’t mean using them at the same time. In a perfect world, you would begin your braking at the exact instant that you’ve stopped accelerating.
 

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Left foot braking in mid corner can be used on a front drive car to induce more slip angle in the rear wheels, thus lessen understeer or create oversteer. Add more throttle simultaneously to maintain speed and front slip angles. Then ease off the brakes to accelerate out of the corner.

Kiyoshi
 

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There is no reason in a normal car to make the car and brake work against each other,
Ummmm, no, lots of reasons. Think of left-foot braking as instantaneous, modulated brake bias. Using brake and throttle at the same time can, for instance, effectively negate the accel/decel loads on the tire, allowing for maximum lateral tire grip. Or, if you're diving into turn one at PIR in your Cup car, you want to a) keep the transition smooth and b) keep the back end of the car under you by allowing for a little momentary front brake bias.

with the exceptions of turbo automatics...In standard cars, the engine rpm is directly related to wheel speed (unless your clutch is slipping), so staying on the gas doesn’t help at all.
Again, no, not true. Klaus Ludwig used to drive many corner in our turbo cars WFO, modulating speed by left-foot braking. Benefit? No spool time - yes, engine RPM is down; but the engine is now running at WOT, making max power, and thus no turbo lag.

The point of left foot braking is to reduce that fractional time it takes from moving the right foot from the gas to the brake, but that doesn’t mean using them at the same time. In a perfect world, you would begin your braking at the exact instant that you’ve stopped accelerating.
Ack, no. For the reasons, and others, mentioned above, there are many points to left-foot braking. In a perfect world, I'd have each caliper with it's own micro-pedal affixed to the toes on my left foot, with the big toe dedicated to a max brake setting. A little training, and I'd have VSES, VSA, all those acronym-happy stability programs beat.
 

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I don't have some big drawn out explanation on left foot breaking but I use it reguallry in auto-x for 2 reasons; 1. hold boost in breaking zone before sweeper or 2. to upset the blanace of the car to weight the front for turn-in.

Either way it is really a stabbing motion at the break pedal with the left foot and not so much a using of the brakes normally.
 

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sr71bb said:
Ummmm, no, lots of reasons. Think of left-foot braking as instantaneous, modulated brake bias. Using brake and throttle at the same time can, for instance, effectively negate the accel/decel loads on the tire, allowing for maximum lateral tire grip. Or, if you're diving into turn one at PIR in your Cup car, you want to a) keep the transition smooth and b) keep the back end of the car under you by allowing for a little momentary front brake bias.


Ok, I didn't think of the biasing part of it.. In a FWD car, giving it gas while braking would essentially bias the breaking toward the rear, since the throttle would reduce the braking of the front wheels while not effecting the rears, and vice versa in a RWD car...

Again, no, not true. Klaus Ludwig used to drive many corner in our turbo cars WFO, modulating speed by left-foot braking. Benefit? No spool time - yes, engine RPM is down; but the engine is now running at WOT, making max power, and thus no turbo lag.
Ooops, ok, I goofed again on this, too, but I haven't been getting much sleep lately... I was thinking of the turbo in terms of keeping the rpms up, and my brain left off the part about higher engine loads=higher boost pressure.... Not counting the fac tthat you lose pressure when you lift off the gas, too...

You know, if you want to adjust your own brake bias, you just need one of these sttering wheels :D


Until then, there's always the e-brake!

So, uh, I guess I retract most of my arguments... :p
 

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I'd buy a BMW if there was a button on the steering wheel that said "Drink" and it netted results...
 

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Um, people, I have ridden in a vehicle with SR71BB and suspect he already has such system as described with his "micro pedals". Alas, he taught me how to create a manual lsd using the left foot. When accelerating with a fwd inside wheel spins wildly, no? Not with left foot braking. Now as the radius decreases, it may become imperitive to use the cutting brake to bloody well rotate said fwd.
 
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