Q: In one of your Chalktalks (thanks for those!) I asked you to describe car rotation, which you did. But what I didn’t ask was how do I get the car to rotate – how I can initiate rotation in a corner? What techniques to try and practice to do this, on track and maybe on some empty roads?
A: Rotating the car? Just to make sure we’re all clear on it, let me define it. Imagine looking down on a car from directly above it. As it goes into a corner, if it rotates (as if on a clock dial) more than the angle of the corner, then it has rotated. To do this, the rear tires have to have a slightly higher slip angles than the fronts – they’re slipping slightly more than the front tires are. You could say this is oversteer, which technically it is, but since you’re deliberately making the car do it, then it’s considered rotating the car.
So, how do you rotate the car? It all comes down to the timing and rate of the release of the brakes. The timing is when you start releasing – before turning into the corner, at the same time as you turn in, or after you turn in. The rate is how quickly or slowly you release the pedal. When you get it just right, the car rotates because you have the front loaded a bit more than the rear, and therefore the rear tires have a little more slip angle than the fronts. To practice, take a session or two to experiment with different timing and rates of release. One time (in one corner) release the brakes early and quickly; then another time late and slowly; then early and slowly; then late and quickly. Doing that, you’ll find how your car reacts to each of those; do it enough and you’ll build a mental database of “When I do that, the car does this; when I do this, the car does that…” So then when you want the car to do “this,” you know to do “that.”
There is no magic formula that works for every car and corner, and that’s why you need to experiment with it. But when you get the timing and rate of release just right, the car will rotate – and you’ll love it!
I can’t recommend practicing rotating the car when on the road, but you can still be aware of the timing and rate of release of the brakes, and that will help when you’re on the track.
You were correct about not practicing rotation on the road. One shouldn’t be traveling at road speeds where rotation is an issue.
I had the opportunity to be at a track event with Mr. Bentley this year. We had a mixture of dry day 1 and wet day 2.
We were asked on day 1 to experiment with the end of braking point and see its effect on the car as it approached the apex. It was amazing. On day 2 in the wet it made it a ton of fun. Instead of driving on pins and needles, I began commanding the car into the corner using EOB and release speed to set the slip pre corner. It gave me tremendous confidence in the wet and set the stage for another chapter in my driver education. By setting the balance of the car I could predictably set slip into the car and manage it through the corner. My only issue was my habit for favouring oversteer.
It has completely changed the way I drive. Over this season I have been honing in on the correct amount of rotation. I have found karting to be an excellent teacher of how narrow optimum slip is and what it feels like.
My next challenge is refining my driving to ensure I’m not limiting the car. It’s easy to toss the car and feel like a hero. However it’s also easy to impose a fake limit by doing so.
Don’t be afraid to make mistakes, also jokingly referred to as learning-takes.
Nice! I’ve read your description of rotating the car in other Speed Secret media or forms on other occasions and I do believe this is the most clear and succinct description thus far. Well done! Now I just need to demonstrate it successfully and repeatedly! Thanks!