Originally Posted by broken-wrangler
Less resistance and breathing better. A bigger hole is better
An engine is only a fancy air pump. It can only suck in so much air, which is determined by the size of the valves, cam, and pistons. To increase air going into the engine you must increase these components first. If these components require a 60mm bore then increasing it to 100mm or 200mm won’t make any difference. Just as your lungs can only suck in so much air due to their capacity and a bigger mouth won't help. Good job doing it, but as I have already done it I can tell you it doesn’t help.