Wheel limits?

My friend and I were a bench racing session, and were discussing wheels for Texas Mile. The question was, At what point will a cast wheel fly apart due to centrifical force? Is there a set speed or rpm that wheels are rated for?

Long story short, unless you're building a landspeeder don't worry about it - just get the wheel balanced to be safe. The force from hitting a nasty pothole tooling around in town is way worse than what the wheel will see at 300-400kph.

To figure out the safe maximum speed of a wheel would take either destructive testing, simulation, or a metric E36 M3-ton of hard math.

In my limited experience with a wheel centrifuge, the tire is the fail point, not the rim.

Yep the tire will go loooong before the rim, in fact a lot of the new "hypercars" need custom tires to stand up to speeds of well over 300kph, and of course landspeeders use custom tires or even solid aluminum "tires" for the really crazy jet/rocket powered stuff...although that's not the point of this discussion.

There are flywheel formulas out there.
Basically when the centrifugal force at the outer edge approaches the tensile strength, you should run for cover.

a properly balanced rim with no runoff.. will not see enough centrifugal forces to be detructive at 200mph.. now a damaged rim, that is anybody's guess

Thanks for the input. If your guys were gonna go 200+ in a caged 69' camaro at texas mile, would you preferr cast or forged?

Well of course anyone will always prefer forged if they don't have to pay for it but cast will do. It's the tires you have to watch.There are new higher speed rated tires (beyond Z/Y/W) for high-end sports cars and supercars, look into those:

https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=35

You'll want to get a "(99Y)" rated tire.

Forged would be lighter.. but some rims, like Enkei are spun cast which would be stronger and better balanced than regular cast

Thanks for the advise. There is always good advise on this site.... and some colorful humor.

run steel wheels for safety- this is what NASCAR does and they go close to 210 into turn 1 at a couple of tracks..