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, how come my digital AC is now dead? Normally the screen will turn blue when I turn the key but now its always dead and no function. If I turn on the lights the buttons will light up but not the AC. And funny...