Vacuum Secondaries

Just as an side note I was curious at what rpm the air door on my 800 thunder series started to open and how long it took to open fully. I rigged two leds and some phone wire, had the wire just touching tge door when it was close and the second led wire would just touch the door when open full. I was very suprised to see it starts to open at 2500 and is fully open at 3000 rpm. Taking a fraction of a second. I video taped the lights next to the tach. MUCH earlier and took so much less time to open fully! 500 rpm!