If you look closely you can see that the green line is slightly to the outside of the blue line, and that the green line has a marginally later turn in, and also a slightly wider exit. Now usually running a bit wide at a hairpin is slower, but I have always suspected that taking the fairly shallow kerb on the inside is actually slower. It turns out that my driver was in fact using the kerb, but had missed it accidently on the green lap, and inadvertantly found a bunch of time!

Into the next hairpin you can see why he lost all that time almost immediately, by missing his apex and running into the second hairpin too hot. In the highlighted are in the diagram below the green line shows a higher top speed for that section, but also the green speed trace drops much lower than the blue. This is where that 3 tenths we had in the bag dissappears, in a very slow exit from the hairpin.

Now the point is that without the data we would never have noticed this gain in time, hidden in an otherwise slower lap. And even if we had that information from split times, without the GPS we would never have diagnosed it.

We carried on the day by taking hairpin one a little wide, and resisting the urge to attack the second hairpin so hard, and with practice we found half a second on the hairpins alone. There are a lot more tricks to Rye House which our data revealed giving us even more time, using just the MyChron 4 with GPS..... and we are still studying the data and are ready to try a few more!