I agree Zip about the hammer drop at high rpm, however the twisting forces from hard bite around the corner on a heavy tacky dirt track with spool locked axles is pretty fierce too.
In the modified class with spec tires that only have a stagger range of less than 1" out of the mold, we have no real way to offset tire circumference stagger for the corners, so that's where the rear steer via four bar offset comes into play to keep from twisting the axles from different wheel speeds.
On a drag car hopefully both axles are feeling the same rotational twist and the same tire spin if any, where on a dirt car the rear wheels spin loose in a bind alomst all the time. That's also why it is mandatory in dirt mods and late models to run floating axle hubs so if you do twist break one in the corners the hub and wheel stays on the car until you coast to safety. I have seen many dirt street stock cars without floater axles do barrel rolls coming out the coners when a wheel and hub break off... :shock: