Now you have a stopwatch, and either the RallyTracks app installed and working, or a GPS that will show average speed TO A TENTH OF A MPH. Here's how I use them.
First, we calculated the ideal lap time. That's based on the track's known lap distance: 2.45 miles. At 45 mph, it works out to 3 minutes 16 seconds. As discussed in
Chapter 2. And, as discussed there, expect the GGP to have a range of lap times that earn you a point, a point being a good thing. Last year the range was from 3:14 through 3:17.
Based on that, our target time is either the midpoint of that range (3:15.5) or the computed ideal time, 3:16. Hitting either should get you a point.
So, here's the drill:
Stopwatch:
Navigator handles the stopwatch. Hit the button each time when crossing the finish line. It is painted prominently across the track. Note: the track was refurbished and repaved for this year. I don't know exactly what it looks like now, but I think we'll be able to see the finish line. Navigator should have a clipboard. It will have a sheet where he/she can record the stopwatch lap time for each lap. After the event, Bob has been making the official score sheets available. This gives you an opportunity to see how close your finger-push was, to the track's electronic lap timing gear.
Average Speed Tool: RallyTracks app or a good GPS:
Driver handles the average speed tool. Either the RallyTracks app, or a GPS that will show average speed.
It must read to a tenth of an mph. Zero it each time you cross the finish line. Note your lap time after completing each lap. Record the lap time on the clipboard.
If it's a GPS, as mentioned in Chapter 4, you might need two taps for the reset. The 2nd tap is to confirm that you really want to reset it. So you'd do the first tap while approaching the line, and the confirmation as you cross it.
RallyTracks app:
This very nice app has two minor drawbacks, as I see it.
Firstly, the display is a bit small. If you have a small pad computer with a dash mount, consider using that. Worth a try. Or you might be fine with the display on your phone.
Secondly, after you hit the reset (labeled "Monitor"), it gives no average speed info for about 30-40 seconds. I've never found it to be a real problem in this event. Somewhere in the approach to the back straight, that display starts showing data and it's all good. Just FYI. Not a problem, because you need to drive the grandstand straightaway (after the finish line), Turn 1, and the climb immediately after, as required by the road and your car. It's only after that, that you really have the freedom to adjust speed in an effort to hit a good lap time.
Using the Tools:
Here's what I did in past years:
Just keep an eye on the average speed. Keep it as close as possible to 45 mph.
Then - assuming your last lap was close to 45 mph on the display - see what your lap time was. If your avg speed was 45 (or 44.8 or .9, or 45.1 or .2) and your lap time was 3:16, that tells you that you can use an avg speed of 45 to hit ideal lap time.
What if it's different?
Suppose your avg speed was 45.0 and your lap time was 3:18.
Obviously you need to adjust. Go for a slightly faster average speed, and you'll get your lap time down to 3:16. The reason for the discrepancy isn't important. The avg speed tool helps you get into the ballpark. Don't assume it will be perfect.