2 or 3 motorbikes pulling up to a stop light, revving their engines loudly to show everyone just how large their exhaust tips are, and then driving away. Sorry, i don't know make or model of the bikes.
A recording of a harley davidson sportster from about 25 years ago. Used re-20 mic running to a symentrix 528 mic pre. Includes engine starting and idling with occasional revs. Then the engine is shut off.