Brake Planner

Pedal pressure, turn-in and ABS points for braking into a corner at the grip limit. Pick your car, set the speed and corner angle, and copy the pedal line on track.

Inputs

Estimated grip
200km/h
90°

Fastest apex for this angle: 108 km/h

108km/h
Grip, corner size and ABS
1.40g
+0.20g
100m
3%

Selecting a car fills in its grip values. Estimated values are rough guesses, not iRacing data. Editing a grip value switches the car to Custom grip. The angle becomes a radius by assuming the corner is an arc of the length above, so a longer arc means a wider corner. Cornering uses the same grip as braking. The tolerance is how far over the limit the pedal can go before ABS steps in or a wheel locks.

Result

83m

braking distance, brake point to apex

Pedal 100% at the brake point, trailing to 14% at the apex

Turn in at
33 mafter the brake point, pedal 96%
ABS if held at 100%
24 mafter the brake point
Braking time
2.03 s
Cornering grip at apex
99%Radius 64 m

Brake 83 metres before the apex, from 200 to 108 km/h in 2.03 seconds. Turn in 33 metres after the brake point.

Brake pressure graph

21 m into the zone: 178 km/h, pedal 97%, cornering grip used 0%

Pedal curve as a table
Speed, pedal and cornering grip along the braking zone
After brake pointSpeedPedalCornering grip used
0 m200 km/h100%0%
8 m191 km/h99%0%
17 m182 km/h98%0%
25 m173 km/h97%0%
33 m163 km/h96%0%
42 m153 km/h94%16%
50 m143 km/h89%33%
58 m132 km/h81%49%
67 m122 km/h69%66%
75 m114 km/h52%82%
83 m108 km/h14%99%

100% pedal means threshold braking at your entry speed. Grip is shared between braking and cornering, so once you turn in, the pedal has to trail off, reaching zero at the apex when the target is the corner's limit. Past the limit the ABS takes over (or a wheel locks) and the stop gets longer. The 10 m on each side show the pedal stepping on and coming off. Dry track, no brake fade.

How to use it on track

  1. Pick your car. Its grip numbers fill in. “Estimated grip” means a starting guess for the class; “Measured grip” comes from telemetry.
  2. Set your speed at the end of the straight and the corner angle. The apex speed jumps to the fastest the corner allows.
  3. Find the brake point. The big number is how many metres before the apex to start braking. Count back from a marker board, kerb or shadow you can see from the car.
  4. Copy the pedal line. Hit the pedal hard at the brake point, then bleed it off as you turn in. The curve shows how much pressure to hold at each point.
  5. Watch the red zone. It shows where holding full pedal would trigger ABS or lock a wheel. Ease off there and you stop sooner.

What the numbers mean

Braking distance
Metres from the moment you press the pedal to the apex.
Turn in at
Where to start steering, measured from the brake point. From here the pedal must trail off because the tyres are also cornering.
ABS if held at 100%
As speed drops, a downforce car has less grip, so the same pedal would exceed the limit. This is where that starts.
Cornering grip at apex
How much of the tyre's grip the corner uses at your target speed. 100% is the limit; above it the car runs wide.

Assumptions

The model uses one grip number for braking and cornering, grip that rises with speed squared (downforce), a corner of constant radius and a flat, dry track. Brake bias, pedal ramp rate and brake fade are not modelled. Read the full method and its limits.

Train the pedal line

“Download pedal curve” saves the curve as a file. The RaceBoost desktop app will use these files to train your pedal input and show the brake point as an overlay in iRacing.