How can I tell what the proper corner entry speed is? Most times I find that I can get on the gas before the apex but much of the time the car understeers. Setup changes haven’t helped much. What am I doing wrong?
It sounds like you are over-slowing the car and popping a wheelie too soon! Let me explain.
A basic rule of thumb is if you can get on the gas before the apex, you’re too slow. Applying the throttle too soon often leads to understeer as well. Let’s take a step back to understand why. First we need to think about the basics of weight transfer here – and remember one of our main jobs as drivers is to manage the car’s weight.
When we accelerate the weight transfers to the rear and when we apply the brakes, the weight transfers to the front. Turning the wheel transfers weight from side to side. We drivers are weight managers.
Let’s go back one step further and talk about where grip comes from. Grip comes from the weight of the car (or in some cars, aerodynamics) generating load on a tire – pushing the contact patch into the ground. The load on each tire changes as the car moves and weight transfers (this is true even with a big aero machine). As managers of said weight transfer, we are, in effect, managers of tire load and, therefore, tire grip. Hence, a driver actually has a lot of influence over whether the car understeers or oversteers.
As my dad used to always say, “For every action there is a reaction.” And, in the case of acceleration, as weight transfers to the rear, it is removing weight, load and grip from the front. When you get on the power before the apex you are taking the load off the front tires right when they need it the most. You can’t pop a wheelie if you still need to steer!
The old textbook stuff about accelerating as you unwind the wheel makes perfect sense. If you want to drive at the maximum (with maximum corner entry speed), then you NEED every ounce of the front tire’s grip to steer to the apex. Always remember the second you touch the throttle pedal you are taking load OFF of the front tires. Don’t unload the front tires until you have got enough turning done. Now, if you simply wait until the apex to get back on the power, this might cure your understeer. It might also cause you to lose a lot of speed.
So, to get back to your question of searching for the correct entry speed, you have to experiment with going in a little faster while waiting a little longer to get back on the power. The key to this is baby steps. Increase your entry speed by no more than one or two mph at a time. You can do this by braking a little lighter, or by braking a little deeper. What we’re trying to achieve here is the point at which it starts to become difficult to get to the apex – even while you are off the throttle – OR – finding the point where you can get to the apex, but have to cross it first before getting back on the power.
Generally, we can use where we go back to power as a gauge of entry speed. If you can hit the apex and get to the power before the apex you’re too slow. If you can hit the apex and must wait until after you cross it to get back on the power, you’re too fast. If you can’t get to the apex at all… look farther ahead and slow down! The truth is, it differs from car to car. The best place to get back on the power in a Formula Vee is often very different than it is in a heavy GT car, but as a general guideline it’s a good starting point.
Yours in driving,