When I owned my R33 I used to sit on the rpm limiter and ran 14psi through the stock turbo, WITHOUT a FMIC and turn it straight off, did it for 2.5yrs, flogged the crap out of it, never had a problem with the turbo........ gearbox suffered and so did the bottom end, but not the turbo..........
Anyway how long does it take for a turbo to stop spinning? As when I park I always let it sit idling whilst I am getting all my stuff ready to get out, and usually to max my time in the air-con as rocky heat is bad, so really I am my own turbo timer, although it is never more then about 20-30secs sitting on idle, surely if I have been gently driving it then that time that I spend sitting there is enough to let it slow down.
Also whenever I am parking it I usually take 3-5mins to find a park, and doing laps of carparks at less then 10kph or taking the 5mins it takes me to get up my driveway, (true ask captainsane I have the driveway from HELL), surely that all adds to the "cooling" and "slowing" time?
All up I think I do a more then average "cool" or "slow" time just by doing these couple of small, easy things, so why do I need to let it idle there for another 1-3mins?