> wrote in message
oups.com...
> Byron, glad you remember me. I haven't been doing much in the sim
> world lately. I'm hoping rfactor will change that I'm racing karts
> right now, which is the reason for my question...
>
> I'm building a new kart chassis. It's designed already, and I've
> welded the basic structure together. The idea of the design is to
> apply the idea of a rigid race car chassis to a racing kart. The
> center section of the kart is designed to be rigid. All the flexing in
> the chassis will be isolated to the front and rear tubing.
>
> So this is new gound I'm breaking here in terms of karting, but I
> figured there might be some car chassis design guidelines regarding
> chassis rigidity for varyious types of cars. And if there is, then
> someone on RAS would know. This information is probably in Milliken,
> but I don't have access to that book right now. I could add as much
> structure to the center section as necessary, but don't want to go
> overboard.
>
> As for measuring chassis rigidity, it's a common thing. The units
> would be force per unit of deflection - like lb/in or kg/mm, same as
> wheel rate. Rigidity is measured like you guessed, pin down three
> corners, apply a force to the fourth corner, and measure deflection. A
> car with a stiffer suspension would need a stiffer chassis to properly
> distribute roll torque.
>
> I know stiffer is better. But, stiffer is also heavier, more
> expensive, more time consuming, and more restricitive to the design.
> If I knew that street cars typically have a chassis rigidity of 1% of
> wheel rate, then I'd use that number as a target for my kart chassis.
> If the ratio is more like 1:1000, then I'm in trouble
>
> BTW, what is FFS?
>
> Thanks,
> Pat
>
I don't think comparing kart and cars chassis is a good idea. Cars have
suspensions, karts don't.