View Single Post
  #7  
Old 12-03-2013, 06:55 AM
md11 md11 is offline
Novice
 
Join Date: Aug 2013
Posts: 21
Cars do not explode, not even if involved in direct impact crashes. Fuel tanks are not pressurized and have specific valves so that the internal volume is always in contact with the external environment so that an explosion can't happen even if you put a lighter in the tank. Seemingly, the inertial switch turns off all devices (so even the fuel pump) upon impact. A fire occurs when fuel leaking from the fuel tank (the fuel lines should be isolated as the fuel pump isn't active any more) reaches a hot spot.
Speaking of this crash specifically, on Google Maps you can find images of an exposed gas line near the side walk basically in the position where the car crashed, so this could explain at least partially the strength of the fire.

Also, when a mid engine car split in half, the separation point is between the car and the engine. It's designed to do so because the engine and gearbox are the largest high density components of a car and separating them allows to remove quite some kinetic energy from the cabin itself and leave it to the engine. Hypothetically, the cabin will stop moving/rolling in much less time than the engine or will have to dissipate less energy in case of a second impact.
Looking at pictures it seems this tub was divided in two right in front of the firewall, sort of where the seats are positioned. While this is not the strongest part of a car, it's a bit too much for a 100 mph crash compared to others I've seen (pictures, video, of course). Also because the fracture is on the side of the car facing the road, so it must have turned around at least once after the impact, so a part of the energy was not dissipated on impact but afterwards.

That said, it's impossible to say anything about the crash or chances of survival with a different car. We don't know much, actually we know nothing, not even if the car was already damaged in another crash, for example. For all we know the car was damaged heavily but the division was a result of the fire.

If there were much more technical data available, it would have been interesting to evaluate the influence of having a rear subframe in carbon fiber as well, unlike most supercars.

Two men died in a crash, which is sad, but they weren't exactly at walking speed, and many more people die everyday in much less prestigious cars just doing their jobs.
Reply With Quote