Jack667

My best example of this is at Road Atlanta at the bridge before the downhill leading to turn 12...
I often have students who've had instructors that get them overly focused on one of the 3 colored squares. The student explains that they've been told to aim for the yellow square, for example.
Meanwhile, they're bombing down the hill and running out of road on the left or right side of the track.
I need to tell them that it's not so much about the position of their car under the bridge, as it is about which direction your car is pointing, or oriented, as you pass under.

Veloce Raptor

^^^yep!^^^

ProCoach

Bingo! Big difference where you START the trajectory that allows passage under the lights... BOTH lateral position and depth of turn in.

Much more fun when there was no 10A-10B!

Manifold

Conceptually, I find it helpful to think of yaw and trajectory as two separate things which happen to be correlated. I look at yaw as an indicator of generating slip angle and cornering grip, whereas the trajectory (on which the yaw is superimposed) is a function of the grip and all of the driver inputs applied through time.

In the illustration Adam posted, which shows the higher apex angle for the more powerful car, we can see that the angle is independent of the yaw, since it's tangent to the trajectory. We can also see that, regardless of yaw, the trajectory will go off the track at the exit if the turn-in is way too early. So, again, yaw and trajectory can be separated.

But the correlation between yaw and trajectory is substantial and interesting, because trailbraking with a spiral corner entry will result in the car's attitude changing due to both the curve of the trajectory and the development of yaw (as use of grip is transferred from braking to cornering), hence the often pronounced sense of rotation during corner entry.

In addition, if the car is low-powered, the trajectory past the apex will tend to be circular, which means that the yaw will tend to be carried through the corner, whereas with a high-powered car the yaw will be reduced somewhat through the corner exit as some use of the grip is transferred from cornering to acceleration. But even with high-powered cars, my observation is that the yaw is usually not fully 'taken out' until near the track-out. I find that many drivers (including me) were taught to unwind during corner exit past apex more quickly than they need to, which results in 'wasting' grip and slowing them down overall - I've had to unlearn that.

Juha G

double post

Juha G

Lot of great discussion and info going on here!!

To the original posters question, I am still insisting you need seat time to not only find your cars limits but to push them and learn how to stay just within the limits.
i.e. basic car control.

To show what I mean with car control, just a short clip/collection from fridays free practise, I was out on old rubber and the track was slippery as hell. Tried to keep the car from sliding but it was very difficult.
This kind of "going over the limit" you learn by just driving the car (don't really need a coach for it IMHO), going fast on the other hand will need more than just car control, it needs understanding complex situations and a good coach will for sure be worth his/her weight in gold for us mere mortals.

DTMiller

Great Speed Secrets Weekly (#238) on this topic today.

Bill Lehman

+1, The best Speed Secrets article I've read.

ProCoach

And it's written by Ross!

Dr911

Check on today's Speed Secrets Weekly.

Steve113

Not to be an *** but you are finding your own limit not the cars . Most people feel that they progress in the sport and there car is no longer fast enough because they "found its limit". Impossible to go faster

Then a real pro or a real hot shoe is asked to drive the car and they are fast then the owner. The owner cant understand how that's possible he/she was driving the tires off the car. There are veryyyy few drivers that really find the so called cars limit . Especially the insanely capable cars of today.

I have the records in GTC-3 Cup at Lime Rock and NJMP . I still have not found the cars limit only my own.