i know it is not a hahn kit but gives you a idea what a good powered 420a sounds like
http://videos.streetfire.net/search/...740058e150.htm
and
http://videos.streetfire.net/search/...740057b01d.htm
and what it sounded like with a stock motor here
http://videos.streetfire.net/search/...0da52ff4c7.htm
for the guy who just asked for sounds in the locked post, enjoy