How long is your driveway / are you backing out at 9000rpm's?
I only ask because I have witnessed a friend (who will remain nameless) in a car (to remain nameless) with relatively quiet factory exhaust rev the piss out of his car whilst slipping the clutch in reverse to back out of spaces.. He didn't even realize he was doing it.. Without eyes on the tach he had no sense of the kind of RPM's he was spinning and it was just easier for him to gas it and lightly slip the clutch..
So - lots of rpm's - almost no application of clutch, just enough friction to make the car roll = possible burned clutch smell.