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Trail braking 101

Trail braking 101

How to trailbrake in ACC

Corner entry is probably one of the most important parts of any track. Get one corner entry wrong and you might end up ruining several following corners altogether. Why? Because it determines for a great part how you’ll go through the corner. Meaning when you’ll hit your apex and, also importantly, when and where you’ll exit.



Every corner is made up of four parts.

  1. The first is the braking zone. It’s a rather simple part of any corner to spot. Basically, that’s when you roll off the throttle and start applying the brakes. It’s an important section of the corner because it will set the speed at which you will take your corner.
  2. The second part is the corner entry point. A good example is the first turn at a track like Monza or Spa. For a large part, you’ll be braking in a straight line. That’s great because that means there is little to no lateral force going through your car. This will help optimize grip levels. But the corner entry part is the tipping point at which you start with your steering input for that specific corner. When done correctly, this will very likely be the same as your braking zone, but more on that later.
  3. The third part of your corner is the most talked about; the apex. There are various descriptions of it. But basically, it’s the point where you transition out of a corner. When you draw a line, it might be early, in the middle, or later in the corner. It very much depends on the corner and the vehicle you’re in. For example, an F1 car will usually apex later than a slower GT3 car. This has to do with the fact that an F1 car benefits from high speed, due to its downforce requirement. A GT3 car has considerably less downforce, meaning you’ll want to spend as little time as possible on the brakes and as much time on the throttle.
  4. And finally, you arrive at the exit. All previous sections determine heavily how your corner exit will be. If you run wide on corner entry, you’ll likely have a late and wide exit. That will force you to back off the throttle or you’ll have to be more demanding on your tires. You might not even notice it at first, but if your tires keep overheating, steering in too late might be one of the causes for it. With basically every car, you’ll want to have the car and steering wheel as centered as possible. The sooner you can go full throttle without too much lateral force, the faster you’ll be on the straight. And in many circuits, that’s where you can gain or lose a lot of time. Especially when overtaking, making sure you have a flying exit is imperative if you want a chance to slipstream your opponent. Otherwise, you’ll end up diving on the brakes, potentially locking up, and running wide.

So how does trail braking come into all of this?

Let’s first start by explaining how you trailbrake. Trail braking is literally trailing your brakes into the corner. In essence, you can brake a little later than usual and keep a progressive braking force applied. In essence, you brake later, but harder and slowly trail off the brake as the apex closes in. Playing with ABS settings (if available) is a great way to hit the sweet spot. If you do it right, you can run that all the way up to the apex, limiting your coasting time. You usually apply anywhere between 30-15% of the brakes.

But won’t that put more stress on your tires? Yes, since you’ll be coasting less,  in theory you’ll stress the tire more. However… trail braking will help you run a tighter line to begin with. Running a tighter line will actually reduce tire wear if you do it correctly because you'll be less demanding on the tire mid-corner. That’s actually where a lot of (bad) tire wear can come from: mid-corner. The moment your start steering into the turn, the tires will experience both vertical and lateral forces. The combination of both is very hard on the tires. The more steering input you apply (on the edge of under or oversteer), the harder your tires will have to work.

So, in the braking zone and/or corner entry, the trailing of your brakes will help you keep a tidier line. You can literally choose whether to run it more towards the outside or more towards the middle (the inside is for overtaking or defensive driving). Importantly, trail braking will help you balance the car’s weight transfer. When you brake hard and let go of the brakes, the car will always have to ‘settle’ first. That’s just simple physics for you right there. Under (heavy) braking, the nose takes a dive. That means a lot of weight is pushed forward. The moment you start releasing the brakes, that weight will be transferred back in place. Your suspension settings determine how fast and how aggressively that happens, but happen it will. The weight transfer itself is essential to compress the front suspension and push the tires into the ground for grip.

But that imbalance can throw your car out of shape. And heavily too if you’re not smooth in the transition from brake to either coasting or throttle. Trail braking will smoothen that transition significantly, meaning the car remains more stable on corner entry. And a more balanced entry will help you be more relaxed, consistent, and focused on the next parts of your corner.

There’s more to it too! Overall, tire temperatures can go down on a straight because the tire surface gets more air. And that’s good if you’re running hot, but if your tires aren't in the optimum temperature range, you might find corner entry to be slippery as your tires are cooled down. You often hear drivers complain about the unpredictable nature of a car under braking. How they to keep braking at the same brake marker, yet run wide... If you’re one of them, well, there’s one more reason for you to trailbrake. Trail braking has the great advantage of slowly heating up your tire for when you need it the most.

How does it influence the rest of a corner?

Put it into practice and you’ll find that the car will really be more stable towards the apex. An important part of racing in any circumstance is looking far ahead. With trail braking, you’ll have a much more controlled entry, allowing you to look ahead with more confidence. That, with the extra benefits mentioned above (tighter line and more grip), you’ll find that braking towards your apex becomes easier and more consistent. From there on out, you can start working towards the exit. Since you’ll be hitting your apexes, you’ll find no trouble getting on the power early and hard. Depending on the car you drive, you’ll experience less understeer and/or oversteer. With oversteer-happy cars, you can sometimes even brake later and correct the slightly later apex by steering the car with the rear. This can be particularly handy in hairpins and banked surfaces like you find in Brands Hatch.

Trail braking also allows you to keep a more dominant racing line going into a corner. You won’t necessarily open the door as wide as you would normally, forcing your opponent to either commit fully under braking - with the risk of running wide - or taking an often slower, dirtier outside line. Ever found yourself stuck behind somebody and can’t find a way to creep inside, yet they’re still running your speeds mid-corner…?

No downsides then?

Not many! Trail braking is something all fast driver do in almost every corner. It’s a good way to be consistent, smooth and fast right out of the gate. If there's a small price to pay it's mainly in error margin. Trail braking means you’re braking late and into the turn. Consequently there’s little margin for error when it comes to narrow corners. Brake too late and you will likely already be on the limit. So, there’s no way to correct your line. Braking harder will likely result in triggering the ABS causing you to run wider. In some cases (mainly with bad setups) the added temperature in the tires will also overheat your fronts, which will become a very difficult and problematic situation if you’re mid-race on a hot track.

It doesn't always work that well in wet circumstances either when there are puddles of water on in the corner entry section. The car might need a little more time to settle in. 

But none of that truly weighs up against the many benefits and better car control. So next time you hit the track, focus on the art of trail braking. It might seem unnatural at first because you’re fighting years of bad habits, but keep at it. Try trail braking in a race, in qualifying, in training, and you’ll find it’s a skill worth mastering. And a skill that can be applied in real-life on twisty roads too!

Image credit goes to: Kunos Simulazioni

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