Ok I'm just back from running some tests with my kev mod / dna stage2 filter .
I have the orignal snorkel but the tube has been removed so the inlet is the same as the dna cover .

kev mod is on 5en a half .

I also have leovince sbk exhaust.

The result is not that big , it's a little bit smoother up in rev's but maybe I was expecting too much ...

now I want to buy the stage 3 side filter ...maybe that will give me the result I'm looking for .

Is it a good idea to leave it on all the time ?

I use the bike for daily commuting but also to take it offroad as much as possible few times a week and offcourse over the weekends/holidays...

what with rain ? mud ? dust ? the filter is straightly exposed to the weather etc ... , will that be any good ?