My start line has a crown on the right lane

[GaryTweet]

When I setup the timing system, the beams are all good except for the start line right side. The outside of the track in the right lane is 2"-3" lower than the center and the left side is perfectly flat. In order for beams to align, I raise the outside unit a couple inches above the pavement. I then stretch a string from the center unit to the outside unit and the string just about touches the pavement in the center side of the pavement. Outside, the string is a few inches off the ground.

I get complaints about the timing is off when regular guys run both lanes. Most of the complaints are on the right side with RT and 60ft off so I assume it is due to the crown, What can I do short of pouring some pavement to raise the right side?

[raceamerica]

Wow, that's a lot of crown for a start line and hard to compensate. About all you can do to minimize the effect is to raise the center unit and lower the outside unit on the right lane. When you stretch a string between them, the lowest spot closest to the pavement should be in the center of the lane. The main problem contributing to timing discrepancies is where the vehicle stages in the lane. Staging to one side will cause the beam to hit the tire at a higher point on the tire and physically stage the vehicle farther from the start line.

Make several passes on both lanes, then take the left lane start electronics and place them on the right lane upside down unplugging the sensor and plugging it into the other lane's cable.. Place the right lane start electronics on the left lane upside down. Run more passes and compare the RT and 60ft differences. If the problem is the physical track, the RT & 60ft difference will remain in the same lane. If the start beams need a tuneup, the difference will move to the other lane.