[quote name='KiLL3r']I don't know, everytime I start a fight in a dark area (with bums) they always show up in 1 minute or 2. I did mine in downtown area(2nd Island), near the safe house. I saw a bunch of cabs lined up and started getting into fight with the cab drivers. The cab drivers are slow and you can counter there punches easily,so you might as well try that. If you run into cops just get in to a car and clear the 1 star, it's not that hard.[/QUOTE]
This is basically what I did. Just started punching cars to piss people off and get in fights.
On an additional note, the 4 minute counter carries over if you get killed. So if you, say, get 8 counters and then die, just find another fight quickly and you can still finish the achievement.