after im done driving my car..i let it cool..cuz i dont have a turbo timer..so i let it idel..i let it ideal for like 2mins..and when i turn off the car i hear a unwinding sound..almsot sounds like the turbo is just spooling down really slow...? .. I cant figure it out...does anybody know what this is..and also i have a 94Z and im having trouble hearing my turbo's spool... the car pulls fine IMO..but i dunno....does anybody have any suggestions of whats going on?

-zak...94 300zx TT