2mm will make the different already. More air to go in to the air chamber and combusion room. That's why some bore it until 64 or 67mm... After market TB like Jun is 70mm at inner diameter. But bigger doesn't mean better, big enough for ur engine OK lar. Don't tell me a stock b16a is going to put a 67mm or 70mm TB.
Guys , help me out , Can I spray Acrylic Lacquer over an aerosol coating ?..For instance , I painted the bodykit with aerosol lacquer black in colour , then could I use an acrylic lacquer ( clear coat ) to spray over...