Not sure about when the turbo comes on, but the OEM turbo is small and comes on pretty fast - you probably don't feel it. I'd imagine it's somewhere around 2500RPM or so. As for idle time, drive out of boost for the last few minutes or idle the car for 30 seconds to a minute or so, and you'll probably be fine (maybe longer if you really cane it while you're driving).
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99 2.8QM
"I've always kept an open, honest relationship with my daughter. Maybe that way she won't fall for the same sh*t her mother fell for." Robert Schimmel
the turbo basically spool at idle... There is no lag basically
The turbo is both oil and water cooled and doesnt need to let idle for more than 5-10secs if driven easy the last min of a trip. If driven hard then parked, give it 30secs
__________________ FACTS > followers 197whp and 292wtq with no chip on stock ic, airbox and catback AEG crank +Scat rods + 83mm Wiseco pistons = CincyTT Version 2.0T