Q: “My car is trying to kill me! 🙂 Going into and through the middle of a corner, it understeers. Then, just past the apex, as I’m getting on the throttle, it snaps into a deadly oversteer. Any thoughts on how to fix that?”
A: Ahhh, the classic “understeer-snap-oversteer” problem.
Certainly this could be a car setup problem, but possibly not as complicated as it may seem. At first, it feels like a two-part issue: an initial understeer, and then snap oversteer. That makes one think that there must be something in the car’s setup causing both, but in reality, most times — but not all times — there’s only one problem: understeer. It’s the understeer, and then what we do as drivers, that causes the snap oversteer.
The biggest challenge is that if I asked you if you could only fix one of these problems — either the understeer or oversteer — you’d most likely go for the snap oversteer fix. Why? Because it’s the one that feels as though it’s going to kill you! But let’s step back and look at this scenario more logically.
As you get the understeer into and through the middle of the corner, what do you do? If you’re like most drivers, you actually turn the steering a little bit more. Why? Because human nature kicks in, and your self-preservation instinct wants you to stay on track when the understeer is leading to the car pushing right off the outside of the track. So, you turn the steering a little more in an attempt to get your car to turn more, and then… with all that steering angle, the front tires scrub off some speed, and eventually hook up and turn. And when they turn the car, it happens quickly! That’s what leads to the snap oversteer.
So, the oversteer is not caused by a setup problem — and definitely not fixed by changing the setup to reduce oversteer. In fact, by giving the rear more grip, in an attempt to reduce the oversteer, it makes the understeer worse, which makes you want to turn the steering even more, exaggerating the snap oversteer.
I can’t tell you the number of very successful race engineers who have related to me that they’ve had very successful professional race drivers do this, and when they do the opposite of what the driver wanted — giving the front more grip to reduce the understeer — it fixed what felt like two problems to the driver.
I’m not saying that your car definitely does not have two problems, but there is a good chance that it only has one, and it’s the understeer. It’s what you do without even realizing it that’s causing the second problem. Again, maybe. If you have data on your car, and you can look at your steering angle, it’s often easy to see a slight increase in steering angle as you try to get the car to turn more, and then a very quick snap of steering to opposite lock to catch the snap oversteer.
If you don’t have data showing steering angle, you may be able to see it on in-car video. Or, you just have to be aware of what you’re doing when your car begins to understeer. If you feel as though there’s a chance that you’re doing anything but reducing steering angle very slightly, then you may be causing the snap oversteer. In other words, when you sense the understeer, you should be reducing steering angle slightly, to give the front tires time and the angle to actually turn the car.
Again, you’re not alone if this is the problem.