Your car is fitted with a number of catalytic convertors so there's no volatile hydrocarbons in your exhaust. The twinspark engine also fires it's plugs twice per 4 stroke cycle (redundant or "wasted spark") to burn excess hydrocarbons when the valves open so even if you removed the cats, the chances are it wouldn't happen...
If you tried tuning your engine richer, the management system would pick it up and you wouldn;t get away with it without all sorts of lights flashing on your dashboard and your engine going into limp-mode..
Thank goodness for that...:cheese:
umm... I vaguely remember that my 159i could do that sometimes!:lol: I haven't driven it in that kind of anger in years! On the overrun, blipping the throttle between downchanges would result in a "blip" sound and at night a feint orange flash was sometimes visible!
My cousin's Rotary engine on his old Capella used to pull orange flames when he let the throttle slip from behind his right foot. Good deterrent for tail gaiters - even in daytime. So get yourself an old 13B rotary engine - that might work. Word of warning though - his consumption was between 3 and 5 km/l. That is 20l/100km if he drove nice and 33l/100km if he put foot - so he just put foot.