turning left, shifting right: why drivers move to the right to get air to the engine

Jack asks:

I’m curious as to why the rear cars are offsetting to the right, when offsetting to the left would let the rear driver see what is happening ahead of them and keep the radiator in cooler air, since the exhaust on these cars is on the right. I know that all those drivers and crew chiefs are smarter than I am, so I must be missing something.

Thanks for the question, Jack. Give yourself a little more credit: you bring up some really good points that I bet a lot of people didn’t see.

Drafting at Daytona has become more important than ever, with the two-car draft being the most effective means of getting speed. The problem is that this mode of drafting completely blocks the front grille, and that limits how much air gets in to cool the engine.  The trailing car has to back off to let air into the grill when the engine gets warm.

Jack noticed that everyone was shifting to the right.  I think it’s a matter of simple geometry and the fact that NASCAR is chiral.  Chiral means simply that something twists one way.  All of your DNA twists in one direction.  NASCAR drivers turn (with two exceptions a year) right left.  (Note:  Thanks to the commenter.  What WAS I thinking there?)

Below, I’ve drawn two cars trailing each other in line on the left, the trailing car shifted to the right (middle) and the trailing car shifted to the left (right).

When cars turn left, a natural gap opens up on the right-hand side between the cars.  Moving to the right takes advantage of the gap and makes it slightly larger.  If the trailing car moves to the left, I don’t think it’s going to get as much air.  So despite the possibility of being able to see better, going to the left doesn’t look as effective to me as shifting to the right is if the goal is to get the most air into the engine.

Thanks for asking the question, Jack!  I always read the comments, so if you have a question you’d like answered, please leave it in the comments for me.

 

 

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4 Comments

  1. Constant monitoring of the oil temp gauge and the water temp gauge gives the real time feedback to the driver that he needs in order to determine which tactic is more effective in cooling the engine. The predominate tactic was to move right so we can conclude that tactic was more effective.

  2. I think that subject was covered in some of the pre-race coverage – maybe during practice, but I seem to remember that several of the practice crashes were caused by the pusher hitting the left rear corner and causing the lead car to spin. Peeking out to the right didn’t upset the balance of the lead car as much if they made contact.

  3. >>NASCAR drivers turn (with two exceptions a year) right.

    “right” should be “left” in that sentence.

  4. Thanks, Diandra. I guess that I didn’t realize that a gap opened up on the right side in the corners. That explains it.

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