Hi Yong,
That what i thought at first, have you actually tried 4-1 yet? The thing is, all this time many friend have told me that 4-2-1 is good for city driving because of its low end power that it gives, and 4-1 were meant for track use because most of the power only happens at the top, but the funny thing is, when i was using the hot bits 4-2-1 system, is feel my power band was at 4k onwards all the way to redline, pulls strongly at around 5.5k, so i decided to be adventurous and go for 4-1, to my surprise the power was instant from low end, and it ended early too, perhap after 6k there wasn't much pull, by the way i'm driving a G2,