News Feed › Forums › The Garage – Go Karting Guides, Tutorials, and How To’s › The Art of Trail Braking – A 5 Part Guide – Go Faster by Braking?
ModeratorApril 9, 2020 at 11:00 pm
- What the hell is this “Trail Braking”
- How can I make this “Trail Braking Thing Work”
- How is this going to make me “Faster”
- What time is good to initiate Trail Braking
- Use the Trail Braking to balance you as a driver
Mr. Mario Andretti once said he was amazed by how “drivers still think the brakes are for slowing the car down”. And he’s right.
As I mentioned, the brakes have much more use for us on track than just slowing a car down. They allow us to control the pitch and weight of the car – front to rear – as we enter a corner.
Change the pitch of the car and you alter the balance of grip from front to rear and visa versa. If you have the ability to modify the balance of the car, then you set yourself up to get the most grip out of each end of your vehicle at all times when entering a corner.
What the hell is this “Trail Braking”
Trail braking is a term used to describe the technique of light braking, yet continuous braking while turning in a corner.
It is a term commonly used around the paddock, but one I rarely see being carried out properly or completely utilized on track. So, I’ll start with the basics.
To trail brake is to blend braking and turning at the same time. It enables a driver to brake slightly later, but more importantly, manipulate the car’s mass to aid corner entry.
This technique is not the ‘racing school’ method of braking in a straight line, releasing the brakes and then turning into the corner. Nor is it necessarily braking all the way to the apex – although that is a possibility.
How can I make this “Trail Braking Thing Work”
Trail braking is a difficult technique to get consistently right. It requires a lot of feel to ensure you’re getting the most out of all four tires at corner entry, but when you get it right, you’ll be fast.
Here’s how to trail brake:
- Brake in a straight line at maximum force
- Slightly before the turn in point begin to ease off the brakes
- Begin to turn into the corner
- As you increase steering angle, reduce braking pressure
- Use appropriate amount of braking to keep a well-balanced car through the corner entry phase
If you trail brake, you’ll be able to brake a few meters later than normal, but as usual, ensure the majority of your deceleration is done in a straight line.
As you’re approaching the turn in and begin to ease off the brakes. It’s important that this part of the process is smooth – begin to come off the brakes too quickly and you’ll unbalance the car.
At the “TI or Turn In” point, start to turn your kart toward the apex of the turn. It’s important to have a good sense of where and when you should be looking for the apex. This is the point where “trail braking” will start, as you’re trail braking past the turning area.
As you increase steering input, to bring the Kart to the apex of the corner, you’ll need to continually and gradually release the brake pedal pressure.
The more steering input, the less braking force you’ll be able to keep until you reach the final 10-15% of brake pressure, where you’ll only be using the brakes to control the pitch of the car.
This is some what technical part, where the kart may over rotate “over-steer” and a soft touch is required for this.
Then, once you have released brake pressure somewhat, begin to turn into the corner. As the kart enters the corner, the amount of trail braking required depends on the balance of the Kart.
Ideally, we want to be using all of the available grip from the four tires which we control by braking slightly more or less and altering the kart’s pitch.
How is this going to make me “Faster”
As I’ve already mentioned, we trail brake so that we’re using all of the grip available – from the front and rear tires – through the corner entry phase.
We can understand this more easily if we take a look at the G-circle diagrams below, showing the grip usage of a professional and amateur driver through a corner.
The G-circle shows the potential grip available for braking, turning and acceleration with the outer ring displaying the maximum grip potential in any given direction.
As you can see, the blue line shows each driver’s usage of available grip. The professional driver is using 100% of the grip available all the way through the corner, but the amateur isn’t quite there. Here’s what’s going on for both drivers:
- Kart is coming to a corner at near constant speed.
- Braking as late as possible, using 100% of grip available. The driver is on the threshold of locking a tire.
- As the pro turns into the corner, he balances the reduction in braking force and increase in steering perfectly, using all of the grip available.
- Deceleration is complete and now the Kart is using 100% of available grip to turn.
- Kart is coming to a corner at near constant speed
- Not quite using all of the grip available to brake and therefore braking too early. The driver may be concerned about locking a tire.
- The amateur driver releases the brakes more when in a straight line and then begins to turn into the corner. As you can see there is more grip available to both decelerate and turn.
- Deceleration is complete and the kart is turning with its peak g-force however, the driver is not using all the grip available and could carry a little more corner speed.
Not utilizing all of the available grip will mean the amateur won’t be able to carry as much speed into the apex, therefore losing lap time.
The driver is keeping the brakes on for too long, giving the front too much grip and so the rear will slide as it’s the limiting factor.
This is a common data trace seen when coaching track day and race drivers, highlighting poor weight-balance management: the kart is on its nose, the front has a lot of grip, but the rear has very little.
How do we fix this? Release the brakes earlier, let the nose rise and distribute the Karts weight more evenly – allowing the rear to grip and creating an even balance.
What time is good to initiate Trail Braking
It should be said that it’s not necessary to trail brake in all corners. Trail braking is best suited to slower corners where we want to ‘rotate’ the Kart before the apex to turn the Kart more and open up the exit, allowing us to get on the throttle earlier.
In faster corners we won’t trail brake as much and we’ll likely come off the brakes earlier (although probably still Trail Braking a little) so that we don’t transfer too much grip to the front tires and can keep the rear settled, which is what you want in the quick stuff.
The amount of trail braking needed for a specific corner isn’t set in stone. You’ll need to be dynamic in your approach as the difference in corners, setup, track temperature and so on, will affect the balance of your Kart and the amount of trail braking required.
For this reason, trail braking is about feel and reacting to how the Kart moves underneath you once you’ve turned in.
Use the Trail Braking to balance you as a driver
Even if you’ve been testing before a race weekend, there may still be instances where the Kart’s setup isn’t perfect once you hit the track and we often hear F1 drivers complain about a lack of balance after a race.
This is where one end of the car generally has more grip than the other and the driver will complain about too much under-steer or too much over-steer.
Trail braking can help cure this somewhat as we can control the weight of the Kart, and therefore grip, if we can change our driving technique slightly.
Imagine you have a Kart that has too much under-steer, where as soon as you turn the car into the corner, the front pushes wide and likely you won’t make the apex of the corner.
With this scenario, there is a ‘front limited’ balance as the front doesn’t have enough grip. When this happens, a good driver will understand that we need to give the front of the car more grip on entry.
How do we do this? Well, we need to keep more weight over the front tires when we turn the car in and we do this by releasing the pressure on the brake pedal slightly later.
This means the front of the car is diving more and has more weight and therefore grip, hence helping the balance issue.
The bottom line!
Trail braking is an advanced technique that’s hard to master – however, once a driver has the feel and experience to get it right, they’ll be faster over a lap and be able to ‘drive around’ smaller setup issues.
Perfecting the technique takes a decent amount of seat time, but a good driver coach will help reduce the learning curve and can assist you with other technical aspects of your driving.
As always thank you very much for reading and if you have any questions, please get in touch. See you next time,
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