Yeah cause the piggy backs (not chip sets) add more fuel but the owners do not add the extra's required.
My Douche-MAX runs a stand alone MoteC ECU compound turbo's// big intercooler/Injectors/Exhaust.
Makes very decent power with very little smoke.... I do a have a "roll coal" button though !
Possibly, if it is an old worn out vehicle.
Newer vehicles, Diesel tuners dump more fuel in to make more power, the black smoke is unburnt combustion.
My Douche-Max rolls lots of coal, More Smoke, More Poke.
Yeah Thailand not same as Australia.... color me surpised !
Incase anyone is wondering, Monday 5th is a sub day for Coronation Day which this year falls on the 4th.
https://www.bangkokbank.com/Bank-Holidays