Speed Secrets: Why Corner Entry Speed Is Critical

By Ross Bentley

October 09, 2015

Speed Secrets: Why Corner Entry Speed Is Critical 
One of the most common pieces of advice given drivers is, "Slow in, fast out." And if you've read any of what I've written through the years, you've heard me say that this often leads to problems. Which is why I appreciate that E. Paul Dickinson sent in an article which looks at this topic in a different way. –Ross
Going too slow upon corner entry creates more problems for the driver than going too fast. Throttle action is smooth with good entry speed, and traction increases. But when entry speed is slow, throttle action has spikes, which presents many challenges that would otherwise not arise with a smooth, continuous throttle.
If you trust your natural instincts, you are pre-programmed (when entering corners that require little brake) to go too slowly and turn in too late. In corners requiring harder braking, you over-slow, turning in too early. You have single-minded reactions to a primal fight or flight syndrome; your realization that more throttle is available after turn-in is, therefore, delayed.
On entry, a car begins to scrub off speed with resistance and friction of turned tires, and speed drops. Your attention swings back and forth, trying to manage reducing speed and varying brake pressure. Speed is hard to judge when it is changing.
Entering a turn, your primary objective needs to be how much speed you can keep, not how much you need to shed.
By the time realization sets in that you could have been going faster at entry, you have arrived at mid-turn. Mid-turn is where you try to make up for the speed you did not keep on entry. Trying now to make up speed by accelerating more can cause you to slide around a little, or a lot. It can also plant the idea you cannot come into the turn faster.
Most mid-turn slides, or spins, are brought on by a sudden realization that more throttle is available after turn-in. Too much power, applied too quickly after turn-in, creates a big jump in acceleration - often more than the tires can handle.
The solution to this mid-corner problem is coming to the turn at the right speed, and maintaining that speed, from entry into the corner. Practice applying throttle pressure as soon as you finish braking - not to accelerate, but to continually maintain entry speed until acceleration can begin.
Another technique is to enter the turn a little too fast (obviously there is a limit) - enough to compensate for the speed scrubbed off by cornering forces, and make rolling on the throttle at end-of-braking a little less critical.
Sound daring? With practice you will find neither are as challenging as you imagined. Managing risk while learning is primary, and there will be failures. Failures provide information to help us do things differently.
If you can see the exit, but the steering wheel is still turned, and you have to keep it turned to stay in the corner, you cannot begin to accelerate because you will not be able to compensate for adding speed.
When we see and hear throttle applied and then reduced coming out of a turn, it is the acceleration out of mid-turn before actually being in the right position to open the steering wheel.
Traction is directly related to how straight the steering wheel is. Only opening the wheel allows significant acceleration. An excellent indicator that accelerating-out will not work is coming off a turn and not being able to unwind the wheel.
Entry, mid-turn, and exit are all different traction zones. Accelerating in a corner can cause the car to slide. Squeezing on more throttle can make the rear tires lose traction. Opening the steering wheel restores traction.
Sliding around on the tires must happen out of choice, not out of distress. You do not want a BIG slide. Big slides scrub speed.
In between there is a slide sweet spot. The tires are not completely sticking, and they are not completely sliding. The ability to control steering with throttle, getting the car up-on-the-tires, lies in that sweet spot.
The sweet spot is usually within a 1 - 2 mph range; make big changes to the throttle, either on or off, and you cannot maintain this zone. If entry speed is off, too slow or too fast, you will never find it, or stay in it.
In this sweet spot, the car handles exceptionally well, with lots of ability to point the car with the throttle and a minimum movement of the steering wheel. Squeeze throttle on, the nose points in; squeeze off, the nose points out.
Most likely it will feel as if the whole car has started to work in unison, as if the suspension is working really well. Look for something controllable and predictable, giving up about two percent of traction - something that assists in turning the car, without scrubbing speed, as you continue to accelerate.
If you are a practiced driver, or are skillful in setting up the car, it will slide evenly. The back will not come around more than the front will turn-in. It would slide predictably at both ends and feel neutral when sliding. In the turn, with a small amount of throttle pressure, it will quit sliding the front, allowing the back to continue to slide under control by the throttle.
You will learn how not to get a car up-on-the-tires the first few times you try it.
Entry problems are caused by going too fast, or braking too hard. Mid-turn problems are caused trying to deal with adding too much power, applied too quickly after turn-in. Exit problems are caused by coming off a turn and not being able to unwind the steering.
Here is an experiment that works brilliantly. Be on throttle at turn-in, but be slower entering than normal - slow enough at turn-in to squeeze on full acceleration. Incrementally work up entry speed by reducing braking pressure. Once off the brake, stay off. Steady acceleration will keep the suspension loaded, generating grip.
Come off the throttle or spike the brake and the created grip is gone, very quickly. That is a sure way to create the idea in your mind that you cannot come into the turn faster, when you actually can. If you never got it to push on turn-in, gather up the boldness to keep getting lighter on the brake.
Master your cornering speeds: Entry, Mid-Turn, Exit and get Up-On-The-Tires.
- E. Paul Dickinson
Web: http://epaul.com​