FWD drag car with a wheelie bar - why the bar?

[matthew1]

[dux02v70]

I used to wonder about that too until I saw a small FWD car rip down the track. When they accelerate, the front of the car lifts up. The only thing to resist it is the weight of the car in front of the rear wheels because the mass of the vehicle is rotating about the rear axle in that situation. With a light car and a short wheelbase you don't get much benefit. If you stick a set of bars out the back and set them on the pavement, now when the front tries to lift it is resisted by the full weight of the car and it is rotating about the axis through the center of the wheels on the wheelie bar. I do wonder why they don't use larger diameter wheels with less friction on the bar but maybe there are rules that govern what you can use.

[matthew1]

Ah, more for traction than safety (flipping). Makes sense, thanks for the reply.

[dux02v70]

You're welcome. Check out some other videos of these things running down the track. it sometimes looks like the rear tires are getting lifted off the ground!