A few people have asked me what it was like to drive Thunderhill at night and I figured the best way to explain would be to show you what its like. This is a quick lap with no traffic from the 24 Hours of Lemons race in December. Its pretty hard to see the course so I have labeled the corners to give you a better idea of the course.
Driving in the dark from rnair on Vimeo.
As you can see, the visibility is not the greatest which makes driving quite an interesting experience. While the lights do give you some idea of where the apex is, the real problem is in finding your track out point. Turns 1, 2 and 4 were especially difficult since the optimum racing line has a very wide track out point where you run over the outside kerbing on the exit. This is all well and good in the sunshine since you know exactly where you are going and you know that its safe. In the dark however, you simply cannot see the track out point when you turn in and you basically have to hope that the exit is clean and that no one has dumped mud or oil on the kerb. The other problem is that its really quite hard to see the track surface and/or its boundaries, especially when people drag mud onto the track. In many cases, the white line marking the track is completely obscured and you just have to guess at what your turn-in point is and hope that you wont put a wheel off on the inside. Some of this might be improved by using better lights: we used the stock E30 headlights and tried spreading the beam sideways to try and light up the apex but since it is a road car the amount of adjustment allowed was just too limited. The next time we will use more powerful, fully adjustable dune buggy lights instead. My solution to the visibility issues was to take it slow and always leave myself a margin for error, it may not have resulted in ultimate lap times but it meant that I always had enough “in hand” to be able to adapt to the any unexpected changes in the racing surface. Our goal was to just stay out of trouble and rack up the laps at a steady pace – since we were in 6th place after 10 hours I guess it did work 
.
The next video is an example of what happens in low visibility, the cars are just entering turn two after someone had an agricultural moment and dragged a massive amount of mud right onto the racing line. None of us can see the mud on the line and come into the corner at race speed only to lose all grip mid corner. One car spins out completely while dPunks and I have some interesting sideways moments. While I got through it ok, it did give me quite a scare and I ended up taking turn 2 quite slow for the next 3-4 laps. Endurance racers who race at 10/10ths all night must be either incredibly brave or incredibly dumb
Muddy moment from rnair on Vimeo.
The next video is of a couple of laps in traffic. As you can see it is actually easiers to drive in traffic since there are a lot more headlights lighting up the track . Also the headlights make it impossible for someone to sneak up on you which means that you always have a good idea of the cars around you and what they are going to do. This leads to much better manners on the track and less problems off the track. Compared to the October race at Altamont the traffic here was incredibly well behaved and there was hardly any contact.
Driving in the dark (in traffic) from rnair on Vimeo.
This final video is a highlights package attempting to show some of the interesting from my 4 hour stint in the dark, I apologize for the crappy editing. All the video in this post was recorded using the PDR100 Racer kit from our sponsors at ChaseCam – I highly recommend it for your own racing/track video.
Thunderhill Lemons highlights 2007 from rnair on Vimeo.
