But Inspector Stewart advised those involved to "think carefully" about what they are doing and to not forget that "it is a police station full of officers who will be ready to arrest those who offend".
"Everyone has a right to protest. If they are on the road, obeying traffic regulations and not obstructing traffic then there will be no problems. They have said it's going to be a peaceful protest. But it will be a different story if they start offending. They will be arrested," he said.
A Facebook page called, CHCH Anti-Police Riot Squad, has not only been used to promote tonight's protest but it's been used to organise other gatherings and aggressive comments have been posted about what boy racers want to do to police.
More than 100 cars are expected to descend on the central police station in St Asaph St tonight.
Operation Hammer involves 25 additional police working Friday and Saturday nights to stop boyracers.
The crackdown follows a similar operation in February, Operation Penguin, where police received 110 complaints about boy racer activity during the weekend of the cancelled Fours and Rotary Autoshow.
Twenty cars were impounded and 41 were pink stickered.
Inspector Stewart said since Operation Hammer started, there's been a 70 per cent decrease in the number of boyracer related complaints.
"Some boy racers are realising that their antisocial behaviour isn't acceptable. But there is still a select few that haven't quite got the message. There's absolutely nothing wrong with these guys getting together in groups and sharing their enthusiasm but when their behaviour starts affecting other people, that's when police have to step in," he said.
Last weekend, a man was arrested for obstruction after he stood in front of a police car and tried to stop them from driving to a scene where others were offending. Four cars were blue-stickered and no cars were impounded.
A blue sticker means a driver has 24 hours to correct their vehicle's registration details or they would receive a $150 fine and their vehicle would be impounded.