Brake pressure sensors are a logical addition to any data logging, whether it be for club level competitors or professional teams. The information we gather from them can help us with both driver and car development.
Case Study One - Three drivers, one car
The track is the fabled Mount Panorama and the corner is turn 23 or Murrays Corner. The car is GT car with quite a lot of aero down force and excellent braking performance. This corner is located at the end of conrod straight that has a terminal velocity of around 220kmh, slowing down to a 90kmh left hander.It also has a downhill approach, levelling out at the turn in point. The braking area is smooth and the corner is well sighted with numerous visual references and braking markers so picking a braking point is usually no problem.
The data was collected over two qualifying sessions on the same car, a current spec GT3. All three examples were taken from the same numbr of laps out and all were verified from the video footage to be clear corners with no traffic to hamper the braking zone.
The first driver is a seasoned European professional with a mountain of experience, especially in this type of car. His approach and initial phase show the hall marks of an aggressive left foot braker. The brake pressure rise crosses over the throttle as it closes so that by the time the throttle is shut, the brake line pressure us already 54 Bar, rising to a peak of 137 bar.
Also of note is the tapering of the brake pressure as the car approaches the corner. This allows the front tyres to have some excess tractive ability at the point of turn in, improving grip in the initial phase of the corner.
From the numbers above, we can see that peak pressure is achieved within 0.19 seconds of initial brake application for a spped drop of 23kmh in 11 metres. Remember those numbers. This is essentially how you out brake anyone in a modern race car. Braking performance has become so reliable and attains such high levels of retardation that it's the little details that make it.
The second driver is a seasoned competitor with multiple national titles to his name, all in touring cars. His initial input is slower and the magnitude is not as much as driver 1.The brake pedal modulation is also not as good with another spike right near the turn in point.
The stats for this are s imilar speed drop to Driver 1 but it's taken nearly twice as long and covered twice as much ground. In fact, he's lost 1 - 2 car lengths........
The third driver is a retired V8 Supercar driver with quite a bit of sports car experience. His initial input is just as quick as driver 1 but he doesn't quite match him for the magnitude of pressure, peaking out at about 90 bar.
His speed drop is only 10kmh over 21 metres and 0.35 seconds. So he's gotten to peak braking force as quickly as Driver 2, but due to the big gap between the throttle coming off and the brake pressure rising to it's peak, the car has rolled without slowing. This is quite evident in the speed trace which has a fairly round shoulder compared to