What Is a Car’s “Rotation” and How Does It Apply to Driving Fast?
Rotation sounds like a simple concept, but there's a lot to it.
In the great, long dictionary of performance driving, a lot of terms get tossed around. Some of them are pretty self-explanatory, some are just synonyms for other words to make things seemingly more complicated. Some are advanced techniques that aren’t the easiest to understand right away. One term that’s pretty self-explanatory, yet also a bit complex, is rotation.
Rotation describes how much a car turns before and during a corner’s apex, and is very useful for optimizing your line through said corner. Another way to word it: How the car’s attitude changes before going off the steering input deep end where oversteer lies – that’s essentially over-rotation. It’s also applicable to corner-exit, too, though not as much.
Imagine looking directly overhead at a car on track, with a big dot right in the middle of the car. Imagine that for every degree the steering wheel turns left or right, the front wheels also turn left or right. Rotation is when one degree of steering wheel turn equals more than one degree of the front wheels turning.
A scenario that demonstrates rotation well is setting up a front-wheel drive car for turning into a sweeper. By setting up, I mean, getting ready to turn in. By altering one’s trail-braking, or, braking and steering at the same time, one can get the rear-end of the car to come around and in the right spot to effectively and efficiently get through the corner. It’s kind of like pre-setting it up for the amount of turning that’s about to happen.
Another way to put it: Playing with the balance of the brakes and the steering wheel to unload the rear tires and make them lose just a hair of grip, so that they’re more willing to change direction.
For rear-wheel drive, a car that rotates well is one that will follow the driver’s steering input and come around without much effort. People say newer Porsche 911s are like this; they rotate around the driver’s seat. Not to serve up a hot take of any kind, but inexpensive enthusiast cars like Miatas and Toyobarus do it well, too.
This isn’t oversteer, because it isn’t requiring any significant counter-steer to correct it. Rotation is simply getting the rear-end to turn around on an axis with the center of the car to be better-setup for the apex.
Rotation Explained Even Further
Rotation is useful in any performance driving scenario: autocross, track days and time attack, and wheel-to-wheel racing. The more quickly and efficiently a car can rotate while still maintaining grip, the higher chance they’ll have of getting through a corner faster than their competitors. Either within feet of them in a race, or through a hairpin between the cones at an autocross event.
It’s quite fun to practice during track days. One fun method of achieving more rotation is what I call “playing with the curbs.” If a corner has curbing along the apex that’s safe to roll onto, one can use it to bounce the car off of, inducing rotation.
Causing rotation is useful at more points through a corner than just corner-entry, though. Regardless of FWD or RWD, sometimes lifting off the throttle in a long sweeper to unload the rear-tires is quite useful. I was taught this by a NASA driving instructor, who called it “corner maintenance”. If you’re coming through a long, fast sweeper, and realize you might not have the best exit, or the exit might end up being off-track, lifting a little to point the nose more inside can help clean everything up.
Rotation is very useful, but it’s best to worry about after a few fundamentals are solidified. Like it’s good buddy and enabler, trail-braking. I said this in a previous post: the more solid of a foundation these… foundational… skills have, the faster your laptimes will drop.