Math/No Math - Great Race

[lugnutz]

Chuck,

Sorry for all of the questions but can you explain how you can stay on time at the check points. I was looking at the sample directions on the ODR website and had a couple of questions:

Instruction 14: average speed of 30 MPH for 36 seconds then change average speed to 45 MPH or

Instruction 24: average speed of 30 MPH, for 1 min and 12 seconds.

Since you are a navigator how would you ensure?? Can you explain (without math/calculations) what you would have to do to ensure that you are on time for each of these legs? And ultimately on-time for a checkpoint. I do unerstand that you will use two stop watches but they do not take acceleration and deceleration into account.

The reason I ask is that it takes time for a car to get to that average speed on the front end of the 36 seconds and the back end of that time when you transition to the new average speed. In order to be on time at the checkpoint you have to validate the time spent to achieve that average speed.

Thank you
Jeff

[Edited on 9-1-2007 by lugnutz]

[Edited on 9-1-2007 by lugnutz]

[ceecpa]

No one is able to regularly zero a control in the GRC.  It happens but there's a lot of luck involved.

You can use only a speedometer, but as many clocks as you want.  One time of day clock and two stopwatches will work great.  These don't need to be expensive clocks - even the $8.00 variety will work fine.

Here's how I'll do it:

1. Left out of parking lot at 10:00 AM plus your car number. You have 30 minutes to reach the start of the speedometer check leg.

We'll turn left out of the lot at 10:00 by my wristwatch and I'll start a stopwatch.

2. Right at Stop onto 360 East.

We'll do that.

3. At "Speed Limit 55" CAST 50 and begin speedometer check. You have 12 minutes and 7 seconds to reach the end of the speedometer check.

At about 29 minutes into the leg we'll stop where we can see the Speed Limit 55 (SL-55) sign.  We'll leave whereever we're stopped early enough to arrive at the SL-55 at 10:30 and we'll pass the sign while rolling.  I'll stop one stopwatch and start the other.  The stopped stopwatch should read 30 minutes. Zero it. Now we're trying to see if our speedometer is like the official speedometer.

4. At "Speed Limit 40" end speedometer check.

At SL-40 we'll roll by at 50, stop one watch and start the other.  We've been driving at 50 and the rallymaster said we should reach that point in 12 minutes and 7 seconds.  If my stopped stopwatch says 12 minutes and 4 seconds I know that my speedometer indicates a lower speed than does the rallymaster, but it's pretty durn close. Zero it.

5.  Left at "MacDonalds" into parking lot.  Begin rest break.  Leave the rest break at 11:15.

We'll do that.

Now we know that our speedometer is "fast" so we'll run a little slower than what the rallymaster says to CAST.  Not much slower, but a little.  For turns you have to speed up a little.  Stop signs and Yield signs will have pauses.  Going into a Stop sign you speed up a little.  Stop one watch, start the other to take out the pause; stop the pause watch, zero it, restart the other watch.  Accelerate quickly to the CAST, run a little too fast for 30 seconds or so, then settle down to the CAST.

You can't get any closer than this in GRC.  It's really a driver's event.