why would one warm up an engine by pulsing the gas? Its fuel injected and controlled by ecu, not like the old carbs with distributors. Now those, during cold morning starts, you need to blip the gas several times to get the engine running.
For most fuel injected cars - this is not necessary. But for a tuned track car - possible that the cams, ECU will not allow the car to idle well. Also you have a larger capacity cooling system, oil coolers, plugs that don't self clean very well, etc. Carbs are the same way - you don't really have to pulse the gas to get them to warm up - even on a drag or road track car - they will just idle high until you get them to temps. I'm guessing this is both a idle issue (keep it from stalling) and to show off to the crowd/journalists a bit.
Even the stock BMW M3 itself is known to be a grouch from a cold start. One could only imagine how something like the GTR would act when started from a dead cold - probably be very much like this vid.
Maybe because it will not idle until warmed up?
Seems like they are just trying to keep it running and the guy at the gas or the linkage itself is too sensitive.
It may not have a cold cycle on the engine.