suspension setup for off-camber turns

Deleted member 1066209 · Nov 6, 2022

Hello, I have a question regarding suspension setup specifically for off-camber turns. It doesn't pertain to a certain game, but also real motorsports as well. I apologize if I've posted this in the wrong section; I'm unable to find a better suited sub-forum.

So my question is: How would you set up suspension to optimize performance in off-camber turns, compared to a turn on a perfectly flat surface? The car in question is a road car, with no aerodynamic downforce options. If you want, you can assume the track is composed entirely of off-camber turns.

I think the ideal setup would be soft springs (low wheel rate), and less negative camber. I believe too much negative camber would lower the tire's contact patch, and softer springs would allow for more body roll, allowing the car's center of gravity to exert a bit more force onto the outside tires. In the same train of thought, I'd probably minimize the usage of anti-roll bars to encourage more body roll.

Am I totally wrong? Is there something I'm not considering? I'd really like to know.

Although I originally specified that this car has no aerodynamic downforce options, I'm curious to learn how it would affect the rest of the suspension setup. I suppose the only change would be stiffer springs, right?

Here's to hoping you suspension gurus can chime in, thanks!

Deleted member 1066209 · Nov 16, 2022

so, uh, anybody have a thought?

I've pondered this a little more in the meantime and am backtracking on my earlier hypothesis about negative camber. The attitude of the vehicle is going to remain consistent with the road, regardless of it being off-camber or not. Therefore, I think you ought to run the same amount of negative camber as you would if the turns were completely flat.

RasmusP · Nov 16, 2022

As far as I can model this in my head, the only real difference is that the lateral G forces would also have a vertical part instead of perfectly horizontal.
So when a flat turn is 100% horizontal, off-camber turns might be 80% horizontal + 20% uplift.
Cambered turns might be 80% horinztal + 20% downpressure.

So in theory the setup would remain to have to be absolutely identical, apart from 2 things:
If the off-camber is not significantly curved below the vehicle, the vertical forces would apply to the whole car.

Which means the setup would be identical, apart from basically considering that the whole car "weights less".

But it sadly gets a lot more complicated since the mass stays the same so bouncing remains to be at the same frequency, the static pressure on the springs becomes less though.

So this whole "spring frequency vs dampers" gets onto a whole new level.

In general though, the tyre camber will be lower than in flat turns since the car will be slightly lifted.
This depends in the suspension geometry ofc. If you'd build a suspension that keeps the camber the same while getting lifted/compressed, it wouldn't matter.
But mostly the tyre rotates during suspension movement.

So in most cars, you'd need:
- Softer springs to allow the car to gain grip
- not much softer dampers since the natural frequency of the car remains identical
- more camber depending on how much softer you set your springs and what type of suspension the car has

In general off-camber sucks because the lateral G forces remain the same due to the mass being identical, but you'll have less vertical tyre load, which directly reduces grip.

Deleted member 1066209 · Nov 20, 2022

Hey Rasmus, thanks for sharing your detailed thoughts!

I applied your recommendations in Assetto Corsa at Mugello and was pleased to discover that I was able to get on the throttle earlier and harder for the off-camber turns.