May 19, 2008

Yaw, Yaw, Yaw

You’ve undoubtedly seen an old car that has been so knocked silly that it seems to be going sideways on the street. We bet you didn’t think that was a performance modification. But right now there is a big controversy in Sprint Cup over an adjustment that has some race cars -- most notably Carl Edwards’ -- crabbing their way around the track.

The rear housing adjustment makes the car look odd going down the straightaways and may adversely affect its top speed, but it gives the car such an advantage going into the corners that it seemingly has proven to be a winning combination on shorter tracks. Edwards, whose Roush Fenway Racing team has been the master of the technique this year, has won three short-track races this season and could’ve won a fourth before unrelated problems doomed his efforts.

One guy who has gone on record as not liking the new gambit is Jeff Gordon.  He has called for NASCAR to enforce its own rules on the subject -- boy, what a rookie he is -- and NASCAR has said it is pretty much doing all it wants to do on the issue. The rule states that the rear housing can’t be adjusted more than a quarter inch one way or the other -- a significant amount but not enough to have a huge impact.

The adjustment creates “yaw,” which is a sideways movement in relationship to the direction of overall travel. Carefully tuned yaw could help a vehicle’s cornering -- especially in NASCAR, where in the vast majority of races, the cars only turn left -- but it could also create some evil handling characteristics. These characteristics are most pronounced at high speeds on long straights, which is why this seems like a short-track gambit.

Instead of legislating or regulating the characteristic away, NASCAR seems quite willing to let the various teams experiment with it. We’re just hopeful that the experiments don’t go too far and result in race cars whose handling is so screwed up that massive crashes are the result.