[AeroMcAeroFace]

Originally Posted by JulianEdgar

So, one of the lowest drag cars ever created in the world to run on a public roads had driver handling issues with just 14 per cent rear lift in crosswinds, but you're suggesting 50 per cent lift would be fine?

To be clear, the car didn't have driver handling issues, and appears to have completed the entire solar challenge with this lift, what the paper says is a precautionary warning:

The reduction cannot be neglected because it translates into a 1.4% and 14.2% reduction in front and rear wheel load, respectively. Disturbances induced on vehicle behaviour by lift force resulting from crosswind, as well as other disturbances by side force and yaw moment, must be suppressed to a level low enough not to disturb vehicle driving.

But the most important thing is that the lift was 10 times more at the back, that is an imbalance, as quoted imbalance relative to weight distribution is the real issue for stability

If the uplift between the front and rear of the car is different, then the slip-angles generated by the front and rear tyres will not be equal; accordingly this will result in an under-or over-steer tendency instead of more neutral-steer characteristics. Thus uncontrolled lift will reduce the vehicle's road holding and may cause steering instability

As far as I am aware, there has never been a road car of any type, ever created anywhere, where aerodynamic lift was a positive.

Considering most road cars have positive lift, and as a result had no additional aero drag because that is how they were designed. Reduced tyre wear, tyre particulates and tyre noise are all positives.

Then I would disagree, the majority of road cars have aerodynamic lift as a positive, at least from a rolling resistance point of view. You may choose to disregard those as positives or claim that the lift induced drag (which is of course true but the form/style was already there) but we have differing perspectives.

However, there has never been a road car I agree (which wasn't exclusively what I was talking about anyway), to my knowledge, that is specifically designed to significantly lift (other than actually flying cars) I will admit.

As we have seen, solar cars can and do preferentially lift, the maths in Permalink 42 support the concept for road cars too.

But the issue of stability requires careful design of weight distribution, lift coefficients, and pitch sensitive lift coefficients to ensure that the lifting force is either central or slightly nose biased to maintain stability under cruise.

And of course rearward centre of pressure in crosswinds to prevent what happened in the solar car challenge https://ecomodder.com/forum/showthre...tml#post648989