Powering Out Of Corners Versus Preserving Speed

Published: August 5, 2013

The usual corner approach taught to novice and intermediate students is to brake in a straight line, follow a late apex line through the corner and accelerate through track out. A variation of this approach suggests beginning to accelerate at the turn in point. Sequence of steps for improving lap time explains why this approach is generally not the fastest, but today we are specifically going to look at taking corners in low power cars like a Miata.

A reasonably good Miata driver executing "acceleration from turn in" approach to corners can be flat out from the turn in. The driver is either hard on the brakes or accelerating flat out, which feels pretty good and objectively seems like a good idea. To be flat out from turn in, the driver might perform most of the needed rotation at the turn in point; if this happens, the driver is hard on the brakes, turns hard at turn in and then accelerates flat out. What's not to like?

The problem with this approach is that once low power cars dispose of speed, they do not easily get it back. By overslowing the car at turn in the car is losing time in every corner. By braking hard it is easy to overbrake from even the "acceleration from turn in" strategy, giving up exit speed. Lastly, if the car car perform most of the needed rotation for a corner at a single point (turn in) it is typically traveling too slowly at that point.

An alternate approach is to trailbrake the car into corners, gently easing off brakes and transitioning braking force into lateral acceleration, and attempting to carry as much speed into the corners as possible. Eventually this approach results in corner entries that are too fast; however, until you overdrive you will be able to approach the grip limit in corners much closer, and this will give you two things. One, you will pick up time almost everywhere on a track. Two, you will learn that you can take the corners much faster while still staying on pavement, which will result in you driving faster everywhere.

I was going to have a data graph here but AIM Solo overwrote the relevant files without warning me, so all I can say is at NJMP Lightning the difference between trying to power out of corners in a stock power Miata compared to trying to preserve speed is at least a second.

Tagged: advanced