2015 Autocross Solo Guide
Chapter 5c: Driving Techniques, Inputs - Braking
Chapter 5c: Driving Techniques, Inputs - Braking
Chapter 5c - Driving Techniques: Inputs - Braking
Braking
You can think of acceleration as managing load to the rear, and braking as managing load to the front. Braking is probably the most difficult input to master. As much variation as throttle can have depending on car, power, tires, and surface, brakes can have all that and more. In general, you want to squeeze the brakes, not slam them. Braking during racing is the opposite of braking during street driving in the sense that when you approach a stop on the street, you coast/light brake, and then squeeze a little harder to make the final stop . When racing, you want to brake hard first (threshold brake) and then ease off as you turn into the corner.
Next Chapter - The LineBraking
You can think of acceleration as managing load to the rear, and braking as managing load to the front. Braking is probably the most difficult input to master. As much variation as throttle can have depending on car, power, tires, and surface, brakes can have all that and more. In general, you want to squeeze the brakes, not slam them. Braking during racing is the opposite of braking during street driving in the sense that when you approach a stop on the street, you coast/light brake, and then squeeze a little harder to make the final stop . When racing, you want to brake hard first (threshold brake) and then ease off as you turn into the corner.
Before getting into actual braking, I should mention throttle lift. Technically this is related to throttle input (or lack thereof), but I included it here because the purpose of the throttle lift is to shift weight onto the front of the car. Your smoothness or severity will determine how the car behaves when lifting. Sometimes cars just need a little bit more traction in the front to dig into the line a little, and lifting the throttle will put more weight and thus traction on the front end of the car. Completely and suddenly lift mid-corner, and you might find yourself going sideways. Just a slight lift may be all you need to tuck in the nose of the car. This is more actively practiced with FWD/AWD cars that tend to understeer, though it is used by everyone.
As far as actual braking technique goes, keep in mind that neither of the Miatas has ABS. That means we will really need to work on threshold braking. Threshold braking is just a fancy term for braking at the limit of the tires. In cars with ABS, you can squeeze the brakes as hard as you want. You don't have to worry about locking up, as the ABS will pump the brakes for you when you reach that point. With the Miatas, brake with just enough force that you don't lock up the wheels. In other words, you want to brake with maximum force while maintaining static friction between the tires and the road. As with the throttle, this depends on all the different factors of the car, tires, and conditions. Keep in mind that if you are threshold braking, you are using all the grip the tires have - don't plan on steering. Threshold braking is what you will do in the straight line you are taking before you enter the corner.
When you've slowed down enough and reach the point you want to turn, you want to ease off the brakes as you turn the wheel. Picture again the string tied to the steering wheel & brake imagery. As you let go of the brake, the string has more slack for you to turn the wheel. This needs to be a smooth process - you can't just let go of the brake and then yank the wheel. Once you're off the brake, you want to be ready to get back on the gas and unwind the wheel to complete the turn. Again, the key here in all of this is smoothly stringing together all of these actions. Failing to do so can upset the balance on either end of the car. Don't overthink the process either though - doing that will result in you taking corners very slowly. Let your body and your instincts take care of it as you gradually build more confidence and skill.
It's difficult to get into things like when to start braking, for how long, etc. because again all of this depends on the situation. For starters though, most novices don't brake hard enough.They brake too early, too gently, and for too long. You want to get hard on the brakes, and often times for autox trail brake deep into the corner. Trail braking is essentially easing off the brakes for the turn like mentioned before, but it more specifically refers to going deep in and keeping just a touch of brakes on through the apex to keep that weight on the front of the car. A lot of novices completely let go of the brakes once they want to turn and this usually results in understeer, as the weight leaves the front just when you need it the most. Trail braking can prevent that. It will also let you practice late apexing, which is what most autox corners are.
I'll just briefly mention left foot braking (LFB) here. Left foot braking is used by a relatively small number of autoxers and especially FWD/AWD drivers. It is naturally suited for most autoxes because we only stay in one gear, and thus the left foot has some freedom in what it can do. It is also used a lot by rally drivers. LFB basically lets you get in a touch of brakes whenever you want without having to let go of the throttle. There's no time lost in switching from throttle to brakes or vice versa, and helps a lot with cars that understeer, as u can essentially shift weight to the front whenever you need a little more bite. It is also very well suited to turbocharged cars, as it allows you to keep the boost up - there will be no loss of spool when you exit the corner if you never let go of the throttle. For us, for our current level, this is unnecessary, especially in the Miatas. your left foot is not familiar with braking pressure, and you will be locking up the brakes all the time. For now, there are other areas to be focusing on.
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Overall you want to use all of these inputs and driving technique to manage the balance of the car. Through your inputs, you have complete control of the car's behavior and a well set up car should be able to exhibit a wide range of handling characteristics. Your goal in getting seat time is to master all of these inputs to reach a level of comfort in the car where, when you see what lies ahead, you will know what line to take, when to brake, how much to turn, and when to get on the gas.


