Adrian Newby wrote:This is close to the line I would take exiting our imaginary 180. I would unwind/go to full-throttle as soon as possible. The rest of my line (before this) would be constant radius.
Ok, let's focus on that apogee point then - the point at which you would start to unwind steering, which in the late apex case is before the geometric halfway point of the corner.
Presumably at this point - the transition between braking and on-throttle - you want to be carrying the most speed possible. To do so means at this point you are using as close to 100% of the tires' friction ellipse for cornering. As a result, there is no spare capacity for doing anything more at this point - once you start to unwind you can get on the gas.
Now let's take that transition point velocity (the point right at the end of your proposed constant radius entry) and apply it at any point on your entry path. Since the radius is constant and v^2/R = a, then your lateral acceleration is the same halfway through entry as it is at your transition point. At no point on that entry path would you ever have any ability in the tires to do any braking.
The only way to be able to brake on that trajectory would be to use less than 100% of the max lateral capacity. On a fixed radius, that means lower velocities. Invariably when you came off the brakes you would not be using 100% of the tire cornering capacity. You could probably make a very abrupt transitioning from constant braking to on-throttle at that point, but invariably you are throwing away mid-corner speed. Worse yet, if you are truly trailing brake (i.e. gradually releasing) on a constant radius corner, then not only are you using less and less of the braking capacity of the tire but less and less of the lateral capacity as well (decreasing velocity on the brakes while holding constant radius, again, v^2/R = a). Heaps of braking and cornering ability being left on the table.
Invariably even if your minimum corner radius was bigger in this constant radius case, it's all for naught as you can never take full advantage of it. Either you carry max constant speed and can't brake, or you do some braking in there and can never be at the max velocity.
Grip is a four letter word. All opinions are my own and not those of current or previous employers.
