mpwolf

Pretty much. But it would work, wouldn't it?

O.W. Kenobi

Are you suggesting that in such a scenario the car would be neutral? I thought such a scenario is what is used to evaluate a car's balance tendencies (over or understeer). I always thought that the car would inherently understeer in that situation, but you seem to be suggesting that the understeer is driver-induced.

nyet

problem is, you can't do it for long, or you'll get throttle cut.

Yossarian

    If your definition of a perfect turn includes a car with a 50/50 balance being neutral, then the "perfect" S4 turn will have a later (and slower) turn-in, later apex, and earlier throttle application.

mpwolf

'bout 3 seconds. =)

VonK :: Retired

Apologies for restating (for completeness) much of what everybody already knows, but IMHO:

"Lifting" is hard to generalize without a specific turn and car in mind. But, understanding the principle of it will help in any turn. In principle, we know that lifting reduces understeer (or exaggerates oversteer = spin :-\ ) because of the aft-to-front load transfer resulting from the momentary deceleration of lifting. At that moment, the front tires grab more and the rears less.

This can be put to good use when a car just doesn't want to <I>come around</I> a turn. At what point to do this depends on the turn. It can be particularly useful in transition between directly connected turns (Summit 6 into 7). But, who wants to decelerate in a turn? The point is to plan for it by coming in fast enough to <b>require</b> the lift, and anticipate the resulting steering response.

Another way to help the car around a turn is to properly set up the entry for what's to come before entering the turn. Then, lifting can be reserved for correction (dangerous!).

Most people think of a car's longitudinal and lateral acceleration, but auto crossers learn quickly about early initiation of their car's rotational (yaw) motion. This is also true for many turns on the track. To rotate the mass of an S4 into a turn requires lateral forces from the front tires, the more so the quicker the car is thrown into a turn or steered through esses. Imagine an S4 on a center post hoist. It doesn't take much force to turn the hoist slowly, but to jerk it around proves how much rotational inertia has to be overcome. It takes time to begin rotating a car into a turn, and it will resist sudden steering input. That's why the faster smooth driver turns the steering wheel more slowly than one who overdrives.

The car's rotational inertia requires initiation of rotation before the turn, especially in esses. At the end of a straight, trail braking can additionally enhance turn-in because of the above mentioned load transfer.

All that said, the theory only helps so much. The real setup, turn-in, and lifting points have to be found by practice, practice, practice.

Sorry about the long sermon.

O.W. Kenobi

Thanks, Harald. I was thinking of Summit 6-7 when writing the post!

VonK :: Retired

NP. :-)