The auto racing season is underway. The 40th Advanced Auto Parts Clash (originally the Busch Clash) ran at Daytona this afternoon (congrats Brad Keselowski on the win) and as I type this the semifinal rounds of the NHRA Winternationals are live on the
tube flat screen. I have never been a drag racer, but they are fun to watch. As an engineering problem the physics are fascinating. The ultimate goal in drag racing is to reach the finish line immediately after the light turns green on the start line either 1320 or 1000 feet away, driven by the wheels in most classes. The chemical and physical bonds between the tires and the track, the thermodynamics inside the engine as fuel is turned into power, and the mechanical transmission of that power to those bonds at the tires, that to me is fun.
SCCA Solo racing is drag racing with left and right turns, so there is some overlap in application to my kind of auto racing in terms of execution but almost nothing in engineering. Drag racing has no lateral acceleration as long as everything runs right as shown when Brittany Force wrecked in the first round of Top Fuel. The word is there will be a report from the hospital at 0800 Pacific on her condition. I sincerely hope she will be OK. For a sport so embedded with fossil fuel use and abuse, there are a surprising number of bicycles in use in the pits and elsewhere in drag racing, so some of Them are really Us.
Brain shutdown thoughts have been on the fact I haven’t included the mounts for the rear springs and swing arms in my plans for the Sprint-T frame. They have a specific place they have to be because the swing arms have a fixed length and connect to something that has to be in a certain place, and they have to be braced in at least two directions so the rear axle doesn’t move around and steer the car from the back independently of what is input at the front. Which is the reason why I didn’t design in roll steer for the rear suspension, because roll steer becomes rear bump steer when you’re just driving down a bumpy road. The slight performance advantage possible racing is more than offset by the possibility of losing control racing or driving on the street. So, the swing arms are level at normal ride height, preventing roll steer or rear bump steer.
And the cat is trying to sit on the laptop so I guess I’m finished.