Can anyone shine some light on this subject. Are velocity stacks worth it? Anyone install these and what were their gains? have an 07 zx6r. I just ordered my header last week and going to be ordering my bazzaz z-fi this week. Im getting the bike tuned come spring time and will also be installing block off plates and adding a BMC filter. Im just curious if these velocity stacks are worth it because if they are ill install them when I got the tank propped up. Seems to me tho that they are gonna add power in the top end. I don't race my bike so if their only gonna take from the lower rpm and mid range and add to the top end I wont do it.