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.
Dear bros,
I am looking for a pair of good condition evo9 GSR seats, if any bros have it, pls pm me. Prefer to deal near causeway or not too far away as I stay in Singapore.. Thanks for viewing..