OK, as promised, attached some pictures from what went on at Botniaring. Granted, some of the pictures lack drama, but have a look. I also attached a pic on data analyses, trying to figure what happened - and not finding much in terms of explanations...
OK, this may not look so bad, but you have to realize that the entire left hand corner of the car was smashed. See the last picture for where this happened (and why...). When the car spun out of control its speed was about 120km/h, and at the impact we felt a vector G of 2.4g... This was a classic I was told, many drivers have experienced the same. After the starting straight there is a tilted 90 deg turn onto the main straight (driven with 3rd gear, throttle on early), and if you go out on the kerb - and especially to its edge - once you drop down the car spins off pretty much instantly...
See the wheel - the deep bend came from something I hit... On the other edge (not visible) of the rim you see two similar notches. These came from the wheel hitting the frame and bending some of the body tubes... Shoot! At the same time, exhaust was crushed and body panels destroyed. See how the wishbones are bent, pretty bad...
Arriving at Vehmaa I just took everything in, and started dismantling. This was day 1, later in the evening. Oh, I sleep in the van by the way (now on evening of day 3, food starting to run out...;-).
Life starting to look better on day 3... You can probably not see it on the picture, but the upper rearmost two tubes (engine bay), one with some silver taping on it, are bent. That is why I had to dismantle the whole car pretty much!!! The wheel hit these tubes and bent them. On the other hand, I guess I am lucky the wheel did not hit my head with that force... Anyways, having space and light, and a clean floor makes the world of difference when you are working! Big big big thanks to Risto Buri and LMS Racing for providing me the space! Now I only have to get Olli Kaurala to weld fresh tubes into the frame...
I made some plots from the data, and circled the relevant parts (for a larger resolution image, click here). I have analyzed the last lap - that ended in the spin - and compared that to my previous lap which was the fastest that day. You can see the place where the spin and crash happened up left (see the circuit website for track pictures, link to Botniaring in my "Links" section), upper right shows throttle and curve radius (essentially how sharply I turn). As you can see, I was not particularly aggressive on the throttle, and my curvature of the turn was pretty much exactly the same as the previous lap! (The rapid increase occurs as the car spins - the crosshairs show a position after the spin has started, but a bit before impact...) Now, lower left shows speed and my X position (from GPS), and as you can see I was following the same path and pretty much same speed. Lower right finally shows speed over 1000 rpm plot, and rpm. Again, the rapid increase in the "speed over 1000rpm" plot shows the car starts slipping uncontrollably, but up until then things were fine. Sure, I switched gears a bit later on the fatal round, but that had little effect in the grand scheme of things (and happened on the main straight much earlier).
So then, what happened? Having spoken to Antti Buri, and recalling what one observer said, I think essentially my rear left wheel dropped off the kerb and onto the sand. Antti mentioned the "drop off" is a bit steep (there is a "ditch" - small, but perceptible), and as the wheel drops off it simply loses all traction. I must have gone about 30cm wide, just enough for the wheel to drop. Mind you, the turn goes in a way that I did run on the kerb at the exit. I was doing this repeatedly. Maybe on the last lap the wheel were a bit hotter, had a bit less traction, and just slightly slid enough to drop off. An observer saw a lot of dust (which you would see anyways...) at the early part of the spin, which would explain this. Details matter, and nowhere more than in formula racing!
In retrospect, I have to pay closer attention, and when getting closer to the edge just make sure I do not drop off. Walking around the track, looking for "ditches", would probably have been helpful too... Live and learn! I hope this helps others so that this type of damage does not happen again.
