TRAIL BRAKING

Yep, another article about trail braking. Ross Bentley has done a Speed Secrets master class and dozens of articles and videos that focus on braking, and Ken Hill also did a great posting on his substack and has many articles covering trail braking. So I’m sure you’re asking, why am I writing another article on trail braking?

Because braking, and specifically trail braking, is the number one area where most mid- and advanced-level drivers can still improve. No single approach works for every driver or in every condition, which necessitates multiple discussions. No single approach works for every driver, in every condition.  

While researching this article, I looked at dozens of videos and articles on trail braking. It was amazing how many definitions existed! For this article, I’m going to keep it simple, and talk about the three Elements that make up the broadest definition, and leave it to you to decide which to include.

THE THREE ELEMENTS OF TRAIL BRAKING 

Element #1 – Race braking – When you come to a stop on the street, you start by gradually applying the brakes, increasing pressure as you slow, then finally reducing brake pressure just before stopping. On a racetrack, you do the opposite: begin braking by quickly ramping up to peak brake pressure and then smoothly roll off from that peak until releasing the brakes completely.

 

Element #2 – Brake Steering – In this Element, you are blending brake and steering inputs at the same time. Therefore, focus on where in the corner you release the brakes. For this Element, the key is to have some brake pressure at turn-in and to continue to release after turn-in.  

 

Element #3 – Rotation – Element #3 is the fine management of the brake pedal and steering to rotate the car (controlled oversteer). This enables better alignment of the car to the apex, and an earlier return to throttle. 

 

The three Elements are in the order of difficulty, and each must be understood and well executed before enabling the next. In the remainder of this article, I’ll break down each Element, explain how to practice them, and provide some simple dos and don’ts. 

Great practice corner – lots of safe run off space and more than 90 degrees

 

 

 

 

 

 

 

Element #1: Race Braking

Understanding race braking

Managing Weight Transfer and Grip – The early peak brake pressure increases your confidence in brake performance. When traveling in a straight line, total grip is available for braking.  Once your turn-in starts, you must divide the available total grip between turning and braking so, by turn-in, you must be down from the peak braking force. 

You get the most braking force when the car is traveling in a straight line, and so that’s when you want to apply maximum brake pressure. As you turn into the corner, you must divide the available grip between braking and turning, and this requires a reduction in braking force.

NOTE: Peak braking doesn’t mean 100% brake pressure, nor does it mean ABS engagement. Peak brake pressure will vary by corner, and you may find that applying the brakes slightly earlier and with less peak pressure can often achieve a better result as it is less upsetting to the car.

Practicing early peak and smooth release

The objective is to consistently reach peak pressure quickly after the BOB (Beginning of Braking) and then control a smooth, steady release of pressure all the way to EOB (End of Braking).

Off-Track: With the engine running, practice the “quick up to peak pressure and smooth slow down to final release” trace of the brake pedal. Use brake pressure data where possible to ensure the release is smooth and controlled. Using a SIM for brake practice is also a great place to start.

On-Track: Start by practicing on corners with longer braking zones, as you’ll have more time to make adjustments. Focus on hitting the same, predetermined BOB point for multiple laps. Use your vision (eyes towards EOB) to guide the smoothness of the release. Feel the weight shifting to the front strongly at first, then slowly moving to a more balanced distribution as pedal pressure decreases. 

Do:

• Start with a very early BOB until you are comfortable with race braking.
• Focus on feeling the weight shift and the smooth release of the pressure both on the pedal and on the force on your body.
• Make sure from peak to final pedal release you are only holding or releasing pressure.
• Complete 80-90% of total braking before turn-in.
• Focus on lighter initial peak pressure if you are overslowing. 
• You can move your BOB point forward in the next step once you are very consistent with Element #1.

Don’t:

• Worry about overslowing when you first start practicing.
• Stomp the brake pedal, instead smoothly squeeze it up to the peak (don’t shock the suspension; introduce it to braking and smoothly/quickly build to peak.)
• Engage ABS. If ABS is engaged you will not be able to manage braking and the pressure control, as it will modify what is peak pressure as it rapidly pulses the pressure.
• Add pressure at or after turn-in, only hold or decrease. (Note: adding pressure at or after turn-in may result in too severe a loss of rear grip and an oversteer moment. If you must add brake then open the wheel as you add brake, then return to turning once slowed sufficiently.)

Element #1 – Race braking example

 

 

 

 

 

 

 

ELEMENT #2 – BRAKE STEERING; BLENDING BRAKE AND STEERING INPUTS

Understanding brake steering

Using the brakes to improve steering response – Extending braking past turn-in and into corner is more about steering than braking. Keeping some extra weight on the front tires provides increased grip for steering as the tires are pressed into the surface. This lets you carry a higher speed into the corner and enables you to get to the vMin point of the corner in the minimum time. It also results in less steering wheel input and improves tire performance and longevity. The most important point is brake pressure and speed at turn-in, as this is how you establish your trajectory through the corner. It may be helpful to think of this Element as Brake Steering.  Use it to improve responsiveness of steering inputs. When you have steered to the line you need to go across the apex and hit your exit, and no longer need to add steering angle, you can be off all braking and either coast or begin picking up throttle.

Practicing feel and control 

Your goal with this Element is to develop feel and control as you blend braking and steering into the corner. Carrying a decreasing amount of brake pressure past the turn-in point, allowing the front tires to remain loaded (creating grip), while reducing speed right up to the corner’s vMin point.  The feel of your body being pushed forward should peak, then slowly start declining, then transition to a smooth diagonal pressure as longitudinal Gs are traded off for lateral Gs. The smooth transition is possible when your steering inputs are coordinated with your pedal pressure reduction. You should also focus on the feel of the tires through the steering wheel. If you are applying enough weight to the front tires you should feel the wheel continue to feel heavier and the car responds well to increasing steering angle. If your speed is too high and/or you don’t have enough weight on the front tires, the wheel will feel lighter and be less responsive (understeer.)

This Element builds on the first one, so before moving on to Element #2, make sure you have the ability to consistently hit the same BOB point, and have a smooth brake release to your EOB. For this Element, you start by moving your EOB target further past the turn-in point.  Your EOB should be near your entry apex, or the closest point to the inside of the corner. Make sure you have begun to come off the brake as you begin steering input. Be ready to make small adjustments in steering and brake pressure as needed.  You are likely to encounter: understeer requiring you to slightly open the wheel and/or holding the brake pressure until grip returns as speed decreases, or oversteer requiring opening the wheel and/or reduction in brake pressure.  

SIMs are an excellent way to practice steering and brake coordination and balance, then in real life the additional feel inputs will help you build the skill.

Do:

• Practice on corners with lots of safe run off space for recovery, longer braking zones, and tighter turns.
• Keep scanning to your EOB target.
• Be ready for steering/brake adjustments, as corrections will be needed.
• Save some braking for after turn-in (if over braking use the same BOB but lower the peak brake pressure.)
• Increase steering angle as you decrease brake pressure (picture a string from the steering wheel to brake pedal – more steering pulls up on the brake pedal.)
• Smoothly release the last bit of brake pressure at the EOB.
• Focus on core body feel and feel through the pedals and steering wheel.
• Be aware of understeer at turn-in (too much speed or steering input) and oversteer (too much or rough braking.)
• Pay attention to steering inputs after EOB, if you added steering input after EOB then you released too early and/or your eyes were not scanning through the corner.

Don’t 

• Continue to hold brake pressure once you are aligned across the  apex to your exit reference.
• Make big adjustments to BOB, EOB, or peak pressures until you are consistently executing.
• Make big increases in brake pressure while still adding steering, remember the string.

 

Element #2 – Brake Steering example 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ELEMENT #3 – ROTATION

Understanding rotation

Controlled Oversteer = Rotation – after conquering the first two Elements you are ready for the third.  Rotation is a controlled rotation of the car about its axis, allowing you to change the direction of the car more quickly than is possible with the steering wheel alone. You achieve this by transferring so much of the available grip to the front tires  – and away from the rears –  that the rears don’t have enough grip to hold the track surface. The rear of the car slides, rotating the car in the desired direction. Weight transfer (grip) to the front tires and steering input initiate the rotation. You control or stop the rotation by shifting weight to the rear by reducing brake pressure, adding throttle and/or reducing steering angle. These adjustments are small and responsive to feeling the car’s feedback. Controlled rotation is only possible when you are at or near the limits of grip before inducing rotation via small inputs.  If you are far from the grip limits, then bigger inputs are required to exceed grip limits and dramatic oversteer is more likely than controlled rotation.

NOTE: while Elements #1 and 2 can be used in most corners,Element #3 rotation is only used on specific lower vMin, higher angle-corners where the additional steering angle from rotation is useful

Practicing rotation

Continue to build on the skills developed in the two previous Elements. You have probably already felt some rotation and/or oversteer. Now you want to induce rotation and manage it on longer, higher angle corners. Remember the goal of all Elements is to get to the vMin point in the least amount of time. Rotation lets you get on the right entry and exit apex angle with less braking and steering therefore less time. The goal is to rotate just enough to align the car to the optimal line without over-rotating. The feeling of the rear moving independently from the front can be disconcerting at first. As you gain control and learn how to manage the rotation it can be one of the most rewarding and fun driving skills to have.

Do not continue to this Element until you have really mastered Elements #1 and 2, and have a feel for the feedback from the car, and have proven that you can respond quickly and appropriately to that feedback in corners. You also have to be at the traction limits in Elements #1 and 2.  If you are way below the limits of your car and tires, you will not be able to induce controlled rotation.  If you are below limits the only way to induce oversteer is to shock the car with extreme brake/steering inputs, which is NOT the approach you want to take.  

First off, select your target corner for practicing. It should have a high angle, low vMin and lots of available run off. Start the rotation with additional weight shifting to the front of the car (braking) in concert with additional steering input. The rotation is managed with reduction in braking in concert with reduction in steering angle. 

NOTE: Some cars and setups are easier to rotate and manage than others.  If you absolutely cannot get the rear to rotate, you can try increasing rear tire pressure to see if that helps. WIth adjustable dampers, stiffening the rear or softening the front can also change the performance in the corner. Make small changes to maintain control.

Do:

• Carefully select the safe corner to practice on.
• Have your turn-in, apex, and exit references identified and practice scanning them on each lap.
• Keep your eyes scanning through the corner to your reference points.
• Be ready to respond to how the car may react to your additional input.
• Try to induce the rotation at or shortly after turn-in as you have the most room for corrections and get the most benefit of the rotation.
• Celebrate when you get it right, you have learned a real high-level skill.

Don’t;

• Practice rotation until you have mastered Elements #1 and 2.
• Expect to do it perfectly, more often than not you will get either no rotation or oversteer many times before you can consistently get exactly the amount of  rotation you want.
• Be surprised when your ability to rotate on demand is inconsistent. Tire condition will change every lap and will require different finesse to manage.  Experience ties feedback to the optimal response.

Refer to How to make a change or break a bad habit

 

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