Ride Height

[Birel99]

Hi,

can someone please explain how ride hight effects the handling of a vehicle.

lets say that their is no ground effects, does lowering the ride hight still improve lateral grip?

my thinking is this= the higher the ride hight (Center of gravity) the more weight transfer to the outside tyres and thus more lateral grip. but the high COG will cause the vehicle to become "sloppy" in the technical areas of the circuit.

Is my theory correct?

Thank you very much!

[WhiteBlue]

hi, ride height primarily influences down force from the diffusor. more ride height and you loose considerable downforce particularly at the rear.

[RH1300S]

Yes it does - the lower the CofG the better for grip.

A little rider I would add - if you lower a standard car, you might put the suspension into positions it wasn't designed for. So the roll centres front & rear may end up not helping things as they will change height and not necessarily by the same amount at each end. Likewise the camber curve of the supension may change (even if the static camber setting is corrected).

You may even get weird stuff like the tyres scrubbing sideways under suspension movement.

Despite the above - lowering a car does seem to help things. Probably a combination of lower & stiffer meaning less suspension movement anyway (minimises the potential downsides) and the obvious reduction in CofG

[donskar]

Lowering a non-competition car will improve handling by lowering the CofG, of course.

Aerodynamic downforce aside, here are a couple other points to consider:

As noted above, the suspension geometry can become compromised to the extent that there is a net loss in handling performance. Bump steer is one common problem, another is a bottoming out, where the suspension hits the rubber stops on the suspension arms, causing a sudden shift.

A positive side effect: lowering springs are usually stiffer than standard springs, so they resist roll or sway when cornering.

[Ciro Pabón]

We have explained how the ride height influences the grip: it's just that the "lever arm" you have on the CoG varies. You can read this:

http://phors.locost7.info/phors01.htm

Or watch this image we've posted a couple of times, you have to read the texts in the order of the numbers.



The same effect applies if you look at the car rolling laterally: you shift the weight. The outer wheel will have a lesser weight, thus less friction. The lower the CoG, the lower the weight transfer. So, a car with a higher CoG brakes and turns worse just because the friction on its wheels is "unbalanced".

On a regular car you can brake so hard as to have zero weight on the rear wheels, thus in an emergency braking you brake only with the front wheels.

I've seen braking marks on the pavement where the rear wheels's streaks are "interrupted" because of this: the rear of the car "jumps" in the air, so you brake ony with the front wheels.

Simple: if you lower the CoG your car will brake in a smaller distance, even if you use the same brakes, tyres, car, driver, etc.

Same goes for turning: you can turn so hard as to "devoid" the outer wheels of weight, thus you take away all the friction from them.

Sorry if you already knew this, but until you understand it you cannot race in a proper way, perhaps someone will find it interesting.