Inside wheel: negative camber vs lifting wheel in the air?

[g-force_addict]

Which is better:

Having the inside wheel touching the ground with negative camber, with the negative camber potentially pushing the car out of the corner via camber thrust

or having too much roll stiffness so that the inside wheel is lifted from the ground?

[siskue2005]

Inside wheel lifting off has the best grip and the best cornering speed
But it's unstable

Neg camber has better stability and less cornering grip compared to wheel lifting off

I don't know if I am right, plz correct me if I am wrong

[GSpeedR]

The fact that a tire is cambered out of a turn, doesn't necessarily mean its resultant force is also out of the turn...it is very likely still producing a contributing force. Not to mention that camber thrust is often not a dominant source of lateral force for a 4-wheeled vehicle (though camber does have an important effect on slip angle generation).

A lifted wheel is hurting you in two ways: 1.) it's useless for generating force (lateral or longitudinal). 2.) once it's lifted, that axle will no longer resist roll moment and your total vehicle roll stiffness will drop significantly as the opposite axle is now providing all roll stiffness. This doesn't bode well for balance if overturning moment has not yet peaked.

[Jersey Tom]

Generally speaking, camber one way or another doesn't mean much at low load anyway. Keep the tire on the ground.

[munks]

2.) once it's lifted, that axle will no longer resist roll moment and your total vehicle roll stiffness will drop significantly as the opposite axle is now providing all roll stiffness. This doesn't bode well for balance if overturning moment has not yet peaked.

Yes, good points. Once a tire leaves the ground, any additional roll will still result in the same grip on that axle, but less grip on the other axle, so balance can change rapidly. For example, if you lift the inside front, I think the vehicle will start moving towards oversteer.

That said, I've seen a lot of FWD cars lifting the inside rear. They've probably stiffened rear roll to counteract the natural FWD understeer, so this might be their least bad option.

[Tommy Cookers]

FWD have relatively high roll stiffness at rear also to help traction, (improved by having reasonable contact force on inner front wheel, this also helps avoid nasty diff steering effects).
Motoring journalists like it.

However, it then becomes possible to lose the back end (and not catch it again) !

Paul Frere was very critial of this.

[Belatti]

I have seen TC2000 vehicles (300HP FWD) lifting on purpose the inner front wheel.

The load sensitivity of the Pirellis they use is neglibigle for the 300kg (static) to 600kg (all load transferred) range. So they choose to do all the traction out of corners using only one tire and avoiding typical FWD US.

The trick? Antiroll bar attached to the hub of cars with a lot of caster (more than 15°)

[marcush.]

a tyre off the ground cannot transmit any force...so deliberatly lifting wheels is sacrifyce 25% of available grip ! Anyone in racing should be prepared to kill when offered as ecret to gain an instant 25 %of available grip for a given situation...

It´s not that easy in real world:

I had more than once situations when completely unloading the inner wheel would actually help the situation of available grip..So in general the first principle applies:
use what you have to the max
but if the circumstances demand try things to make it workable -it is a compromise after all.-at least at the track when you cannot develop a new car in two 30minute sessions..

I don´t see the relation to negative camber though ... but i see a relation to anti ackerman ,providing more lateral grip with less steering lock(= lower slipangle ) at low loads(not true for all tyres methinks).

I always think this could possibly cause unpleasant steering input (going straight ) when you find a bump or high spot with the inside wheel (= load transfer caused by road irregularities).