Some including myself have been preaching this for years. It's the BIG Variances that you notice. What about the -.005 that you cover and maybe shouldn't have and now you're stuck in the high teens all day?

Hopefully this makes you as a racer smarter when dealing with unknown issues you may think are you or your car. Hopefully your track manager or operator is this smart also.

** RECENTLY POSTED BY ACCUTIME **

A Reflection on Reflection - with the advent of improved traction control, shiny surfaces at the starting line can reflect the starting line infrared beams, that you cannot see. But you may see the impact on your rollout. I put together a couple diagrams for understanding and some tips on diagnosing the issue and what you can do to mitigate the reflection. See diagrams.

If your rollout is changing dramatically and less than it should be and fluctuating, an easy way to diagnose whether reflection is affecting rollout is to place a 2x4 (or some block object that is 1/8-1/4 inch lower than beam center line) about 4 feet in front of the outside emitters. This 2x4 blocks the lower part of beam trying to scatter off the track surface.

In a case this past week, a track had dead-on rollout lane to lane for Friday night testing. The next day, the rollout measured by beam height was less than 1 inch after prepping the track. With the 2x4 in place, the rollout measured right back to 1 5/8 inch, with no other changes.

(Every beam height has an equivalent rollout, ie, using a 22 inch dragster tire, a 11 ¼ inch rollout is 1 5/8 beam height, measured in each right and left tire groove).
When does reflection happen? There are so many factors – surface of the track – both slopes and roughness, how it was ground, height of the sensor pads relative to the track surface, how the traction compound is applied at the starting line, dampness. A track may see reflection in one lane but not the other.

What can a track do to prevent the reflection and impact on rollout? There are trade-offs for the possible solutions. You can use tubes on the sensors. Try beam blockers. Definitely, paint the surfaces matte black that you can. Groom the track at the starting line to minimize reflection issues (cover areas to prevent shine where not needed and where the shine interferes with the timing system starting line beams).

Racers, there is more than one way to red light, so it could be you.... this advice is for tracks maintaining rollout after track prep.

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