I currently have the red spring (the louder one), but I still don't think that its loud enough :D

Has anyone tried to block some of the holes from where the air is released? Blocking some of the holes will increase the pressure through the other holes and maybe make a louder 'pssshhht'.

Maybe worth experimenting - what would you recommend using to block the holes (has to be reversible ;) )

[I wish I'd bought the HKS one instead]

Someone?

I was thinking along the lines of using thin nuts and bolts with rubber washers to block off some of the holes...