Many consider left-foot braking an advanced technique reserved for the upper echelons of motorsport. However, we all do it when we get into a kart and there doesn’t seem to be much difficulty in the transition. Why is it so difficult to apply the same technique in a racecar?
As racers, we know how to use a clutch and a manual transmission. Admittedly, even this is a dwindling skill because the three-pedal setup appears less and less on new cars — including factory-built racecars — and as we see more paddle-shift and dual-clutch transmissions, we may see an increase in left-foot brakers. In the meantime, acquiring this skill can be beneficial even in the context of a manual setup. Using your left foot to brake reduces the time between throttle and brake application and even allows for overlap. This gives the driver more options in balancing the car through transitions. This can also reduce the amount of dive by applying brake and gas at the same time. Left-foot braking is particularly useful for turbo cars by keeping the turbo spooled up, thereby eliminating turbo lag.
But what about those karts I mentioned earlier? Why is it so easy to left-foot brake in those? The biggest factor is the unboosted brakes. They also have relatively short pedal travel where the brake force ramps up quickly with pedal force. At the higher levels of pedal force, an untrained left foot has decent sensitivity. Furthermore, there’s no clutch so the left-foot isn’t changing the travel vs. force relationship between pedals. This is also why it’s fairly easy to transition to left-foot braking in single-seaters with non-syncro transmissions that don’t require clutch actuation for shifting.
Street-derived racecars have boosted brakes and the brake force is proportional to pedal travel about as much as pedal force. When you first try left-foot braking with a boosted system you’ll likely feel an abrupt brake application.
Balancing the Car
Unfortunately, things get complicated when shifting is involved. If you haven’t seen Walter Rorhl’s pedal dance in the Audi Quattros of the early 80s, then stop what you’re reading and YouTube “Walter Rohrl footwork.” You can see that he seamlessly jumps between left-foot and right-foot braking when shifting is required. This technique is well suited to rally driving where the objective is to intentionally induce a slide to help steer the car.
Switching between left-foot and right-foot braking in the braking zone on a road course is difficult and generally leads to extended braking distances and a potential lock-up or slide. Therefore, left-foot braking is best suited when clutch application is not required in the braking zone: a high-speed kink for example or a short braking zone. Remember that left foot braking allows us to better balance the car and reduce the transition from acceleration to braking and back to acceleration. If there’s a section of track where you typically lift, this is a great place to try left-foot braking. Keep the right foot down on the accelerator pedal and bleed off some speed with left-foot braking. Being more balanced on all four corners through the speed and direction transitions allows the car to maximize grip and carry more speed.
The safest place to develop left-foot sensitivity is at the track, but that comes at a premium. The alternative is to practice on the street in controlled conditions. You will feel like a new driver the first few times you try it, so make sure that there are few cars around. Better yet, find an abandoned parking lot. Practicing with an automatic-equipped car makes things easier, but learning with a manual can be equally if not more beneficial.
Get up to a reasonable speed between 25 and 45 mph and then practice light braking. Work on getting to a specific brake force quickly and maintain that force for at least a few seconds. Practice a gentle release. Work on building up your braking sensitivity with a range of speed and pedal force. Practice a variety of transitions of acceleration and braking. Also try braking and accelerating at the same time. Notice that there is no amount of accelerator that you can use that can’t be overcome with braking. However, be mindful that your brake boost can be used up if you don’t have some off-throttle moments to replenish the vacuum.
When you’re comfortable in a controlled environment, then practice on a daily basis in your commute. This is when you’ll really begin to develop the subconscious sensitivity for left-foot braking at race pace. After some practice, transitioning to a racecar will be easier. Be mindful that a rear-wheel drive car without ABS will be more prone to lock-up when using left-foot braking, so sometimes right-foot braking is the best option when maximum brake force is required.
Left-foot braking is a great tool in the driver’s toolbox, but it’s not a cure-all for every situation. Use it as track conditions warrant. When you really have a good grasp of the skill, you’ll be able to practice using it in various situations to determine whether it reduces your lap time.
A mechanical engineer and driving coach, Joshua Allan has worked in the design offices of Ferrari’s Formula 1 team and has been a vehicle development driver for Maserati in Italy. He is a five-time Performance Touring National Champion in a Mazda MX-5 with Robert Davis Racing. Send questions for future articles to firstname.lastname@example.org.