Mechanical grip increase leaning INTO corner w/active susp.?

[g-force_addict]

FIA is trying to reduce speeds by introducing regulations that could translate into technical innovations in road cars. (Yeah right!)

Therefore it's possible that FIA could allow active suspension in the future, maybe along with higher minimum height requirements.

How much mechanical grip would increase by leaning a few degrees (5 or even 10) INTO a corner?

Of course supposing suspension design allows taking full advantage of leaning with proper camber, toe, etc.

My (simple math) calculations yield very modest results: g-force increases of 5-7% by leaning 5 degrees into a corner.
Of course it gets way more complicated, beyond weight transfer, you'll have to dig into tire load sensitivity.
So how much steady cornering mechanical grip would increase by leaning?

[WilO]

g-fa,

While I think that a return of active suspension to F1 is optimistic, I would like nothing more than for this to happen...Active suspension presents enormous performance possibilities for racing vehicles, and similar gains in stability/control for road cars (think safety).

A fully active suspension is sometimes referred to as 'irreversible', in that the suspension does not move in response to anything other than instructions issued by the computer. As such, sprung mass inertial movements such as roll and pitch simply do not exist (by default). Absent those sprung mass motions, associated camber and toe changes are gone as well.
Any lateral load transfer will result in a reduction in available grip, due to the load sensitivity effect you mentioned. That being the case, I'm not sure how much mechanical grip would be improved by 'banking' the car through a corner. What might be interesting is instructing the front suspension to take all of the roll resistance, leaving the rear axle evenly loaded for greater traction exiting a corner.
A 'real' answer to your question will have to be provided by someone smarter than me...though I would think that any chassis movement induced by the suspension would change the load seen by the tires (dynamic crossweight would be a factor), and possibly reduce grip levels.

Wil

[Jersey Tom]

You will have a 100% reduction in mechanical grip when you blow the tire out running 10 deg of camber.

[amouzouris]

yeah but you forget one thing...this will spoil the racing...as the driver will no longer control the car but a computer will..

[WilO]

JT (as usual) raises an excellent point....camber angles like that will require a tire resembling a motorcycle tire in cross section...Millikens' camber car.

I disagree with the comment about active suspension spoiling the racing. I believe that a more talented driver will be able to make better use of the capabilities of the car. Gifted drivers (Senna comes to mind as he drove an active car)have greater sensitivity and feel, and I'd like to think that these qualities wouldn't be rendered useless by active.

Wil

[DaveW]

How much mechanical grip would increase by leaning a few degrees (5 or even 10) INTO a corner?

I can't answer your question directly, but I suspect JT has...

In my opinion (& experience), rolling a sprung mass out of or into a corner is not a good idea when the sprung mass has a finite roll inertia because transient roll response occurs, & this causes unwanted CPL transients. I was involved fairly closely with the Lotus F1 active system of 1983 & 1987. Both did "roll in" a little when cornering, but only to maintain a "flat" aero platform by compensating for tyre roll.

Active/passive camber control has been tried on several occasions in F1. The earliest to my knowledge was Tyrrell in 1978 (+/- 1). They tested hydraulic camber control on at least one occasion, but I don't believe the system was ever raced. Since there were no rules against it at the time, I can only assume that the system didn't yield a performance advantage.

[vonk]

IMHO, the only thing you could “lean into” a turn on an F1 car would be the inside wheels (camber) to optimize the tire contact patch. That would have no effect on lateral load transfer. But the inside wheels see only light loads, so the potential complexity of large active camber variation and increased un-sprung weight would not be worth it. As for the outside wheel, current suspension geometry already provides camber variations to optimize the tire contact patch.