To follow up the post after the Hungarian Grand Prix regarding the explosion on Nick Heidfeld’s LRGP car, which aroused great interest from readers, the team’s investigation has now been completed and the results found.
The simplest thing is to let technical director James Allison explained what happened:
Three days after the incident on Nick’s car, has the team identified the reason why it caught fire after the pitstop?
Allision: “As with most accidents, several incidents combined to cause the fire that Nick suffered in Hungary. First of all, we ran a slightly different engine mapping strategy in qualifying, which produced hotter than normal exhausts. We believe that this elevated temperature and caused a preliminary crack in the exhaust pipe. We presume that the crack then propagated during the laps to the pitstop – this was not evident to us as we believe that the failure occurred upstream of the place where we have a temperature sensor. We believe that Nick then came in with a partially failed exhaust. This pitstop took longer than normal, the engine was left at high rpm for 6.3 sec, waiting for the tyre change to be completed. Under these conditions, a lot of excess fuel always ends up in the exhausts and their temperature rises at around 100°C/sec. This temperature rise was enough to finish off the partially failed pipe and to start a moderate fire under the bodywork.”
There was an explosion shortly after Nick got out of the car, on the left. What was it?
Allison: “This was caused by the air bottle which supplies the air valves in the engine. It has overheated in the fire and failed.”
Will you have to modify the car before Spa and if yes, is the August factory shutdown a handicap?
Allison: “The incident was highly undesirable, as it has caused us to write off a chassis. We will take steps prior to the next race to reduce the likelihood of a further fire and to ensure that the air bottle cannot overheat. We are in touch with the FIA both to provide them with a full report of the incident and also to explain to them the actions we are taking to prevent a reoccurrence (sic).”