Bump and grind
One of the great myths that perpetuate racecar engineering is the role bump steer plays. Like its close cousin, roll centre, and anti-dive and anti-squat, if you want to see the sparks fly walk into a bar and full of race engineers and say bump steer is irrelevant. Then sit back and watch chaos unfold.
This recently came up on social media and, after a spirited discussion, a former student of mine suggested I do an article on this. So that is exactly what I am doing here and, after doing some sim’ work, some very enlightening things were found.
What you are doing here is using the bump steer to make sure you can dial in the slip angles you want
Firstly, we need to define exactly what bump steer is so we can discuss it properly. Bump steer is the steered angle of the tyre as the wheel moves up and down. This, which shows a plot of toe angle vs wheel movement.
