Left-foot braking is a technique for a variety of motorsports. It’s somewhat argued, but can improve lap times. It involves using the right foot to operate the throttle alone, while the left foot operates the brake, clutch and rest pedal. It can be used efficiently in any drive, but it is particularly beneficial in FWD, front-engine AWD and mid-engine RWD cars.
It is not recommended on road cars, especially for those inexperienced in it (to which it is generally not advised, unless in a rally stage). The reasons being that:
- The shock it can place on the car.
- Damage to the drive train due to both acceleration and braking.
- Loss of body support by not operating the footrest with the left foot.
First off, we need to distinguish between left foot braking in two different purposes:
- The first being to reduce transition time as you go from pedal to pedal.
- The second is where the driver uses left foot braking to manage weight transfer and torque more sensitively (professionally called “combined braking”).
|Left Foot Braking||Combined Braking|
|Purpose||Reduction of pedal transition time||Increased control over weight distribution and power|
|Conditions||On the straight, usually before a curve that does not require downshifting||While cornering, usually on moderate speed corners|
|Field||Racing, road driving (sometimes), rallying||Racing (rare), rallying, drifting|
|Setup||Regardless of car setup, although beneficial to turbocharged vehicles||Most beneficial in a FWD|
Note: Another, more rare use of the left foot on the brake pedal is actually when accelerating on the straight, in order to check and see if the brakes are still responsive and work effectively.
Combined braking has the following advantages:
- Reduction of understeer before the apex: With left foot braking you can use trail braking through the turn-in point, while smoothly increasing throttle application through the corner. Ideally, you should be able to control weight transfers to enable the car to slip slightly without understeering or oversteering, but in a state of “neutral steering”. This will actually optimize the traction of your tires. Also, should the car understeer due to power, you would be able to punch the brakes hard for a moment, which will straighten you up (lock rear tires).
- Increase of power application after the apex: Oddly enough, covering the brakes with the left foot as you progressively accelerate out of corners will enable better acceleration with less wheel spin and more control. This is particularly beneficial with cars that have locking differentials. The reason is that a very slight braking pressure is light enough to not decrease the power application, but does create a slight conflict which the differential “recognizes” this as the wheels slipping, resulting in it locking-up and giving better transmission of engine torque to the wheels, particularly in a FWD. This can also work in a RWD, but because of weight shifting involved, is harder to perform well.
- Allows for a better control and recovery from oversteer: Left-foot braking is also a method of inducing slides, controlling them once developed, intentional or not, and terminate them, all done far more efficiently. This is particularly useful in rallying or in drifting. Instead of simply using power to terminate a slide or brakes to initiate it, the driver can brake and accelerate to initiate the slide, and then immediately (no pedal transition time) accelerate and brake (the stress this time on accelerate) to power out of the slide. In a rear-wheel drive, punching the brake hard for a moment or so while on the accelerator, can terminate oversteer.
Left foot braking has the following advantages:
- Removes pedal transition time: By left-foot braking, throttle and brake applications will in fact slightly overlap. This allows for a quicker slow down and power-out. This is particularly useful for WRC drivers, who drive in turbo-charged cars. In this case, peeling off of the throttle creates a greatly enriched mixture of fuel and air, that powers up the turbo-charger. Left-foot braking allows you to power out quickly and use this extra boost, without letting the revs drop too low. When the car has no clutch, or when approaching a curve that does not require a downshift (and therefore no clutching), you should do this.
- Maintains brake integrity: When approaching a short braking zone at the end of a fast straight, followed by a sharp or moderate-speed corner with little run-off areas, you should consider dabbing the brakes ever so slightly a bit before the braking zone, to check the feel of the brakes, in order to be aware of possible brake fade or pad knock-back. This should also be done after recovery from an aquaplaning situation or going through puddles.
- Decrease chance of overtake: By rhythmically dabbing the brakes ever so slightly when you are about to brake before a corner, you alert the opponent and also makes a beginner or a competitor unfamiliar to the track unaware of your precise braking point. This helps to avoid being overtaken along the straight before the corner. If you see brake lights flashing slightly a bit before the braking zone, or when coming out of corners, but no significant deceleration seems to take place, you should know that the driver in front is testing his brakes.
Left foot braking has the disadvantage of less sensitive braking and loss of tactile feedback, because the left foot is not used to push the body back into the seat. In a harnessed bucket seat it’s not that serious of an issue, but still decreases feedback. Additionally, it can decrease power and/or induce oversteer, and create inconsistent footwork. This last consideration depends on whether the driver needs to use a clutch. If not, left foot braking becomes far more recommended. It’s also less recommended in a rear-wheel drive, however it is far from useless, even in a RWD. It is possible to Heel and Toe or tiptoe while left foot braking, but it’s a skill and it’s hard to adopt. It’s better to use the right foot on the straight and use the left foot according to the car, corner and speed.
In a typical race car, the driver can adopt left foot braking (in combined braking) while apexing through moderate-speed bends that require a lot of accuracy. The driver should use threshold braking with the right foot before the corner, heel and toe just as he comes to it, and then move the left foot to the brake in order to commit trail braking up to the (late) apex.
Left foot braking (not combined) can be used to brake before a fast curve that does not require a downshift. Usually, there’s no need to continue this drill through the curve, because the corner is best handled by breathing the throttle, especially because the speed does not enable wheel spin.
Left foot braking is also good for drifting if the driver is well-balanced in the seat and if it can help his drifting style.
However, when left-foot braking into corners, you might be feeling as though if you are not braking, but only “covering” the brakes. This is because the left foot has the habit of pressing the clutch deep and quick, or simply squeezing on the rest pedal. That’s why you need to be gentle and smooth.
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