"Catching air"
 

This thread is triggered by a new avatar posted by Flying Finn...

I've seen images of our 993s at speed where one of the front tires/wheels is shown loosing contact with the ground.

What causes the front tire to leave the ground on DE/track events?
Is is something specific to our cars?
Does it occur during "normal" driving"?
Is it good?
Is it bad?

Just curious....

I think it means it's a real car. :thumbsup:

Scott :burnout:

It's the same reason that VW rabbits lift their inside rear tire....

Ok, real answer: It's a combination of rear weight bias, squat, outside tire loading, and torsional flex. Plus, it looks cool.

Check out the Right Rear
 

Laguna Seca air..........................

stiff sway bars help :burnout:

+1

That's not air...........................................this is!


ZP44 :cheers:

Heavy throttle with stiff sways when coming out of a turn will shift the weight rearward, and the bodyroll can lift the inside front tire.

Lifting a tire will increase the load, in varying degrees, on the other three tires which in turn increases the likelihood of overloading your tires causing them to loose traction resulting in understeer or push as they refer to it in NASCAR. Personally, I prefer to keep all four contact patches on the ground when driving @ track speed.

It won't happen during "normal driving"! :D

Hey Gordo...+1 I was taught it is not the best to be packing a wheel around. I also mainly drove SCCA Solo II.

Some lift is normal. A lot (more than a couple inches) usually means you need more spring rate in the rear.

Great!
Thank you all for the education.

It's a combination of a couple things. Soft rear sway bar and stiff front sway bar. Of course, sticky track tires can help alot too. If you have adjustable sways, the "safe" way to set up the car is soft in back and stiff up front. This will keep both rear tires planted while the inside front is very light (or off the ground) inducing understeer at the limit.


The VW GTI's had the opposite arrangment which allowed them to handle very neutrally in fast sweepers and actually oversteer predictably under trail braking. You'd often see them carry the inside rear tire the entire way around fast sweepers but ultimately, when they slid, they did so very predictably. Front wheel drive cars are generally prone to understeer but VW used the sway bars to dial out much of that bad trait in a dramatic but effective way.

MC

^^ That is a cool avatar!! Is that the infamous Laguna Seca corkscrew? I hope the next few seconds were uneventful!!