So today the new High flow air filter from DNA went into the airbox to compliment the Mistral velocity stack. The stack is an absolute work of art, it’s a crime to hide it away lol. The new filter is claimed to give much better airflow whilst giving increased filtration and can be cleaned and reused. I haven’t ridden the bike with it fitted as yet and imagine there won’t be a very noticeable increase in performance, although when combined with the Mistral decat crossover pipe and Mistral v-boost it would be interesting to know what the actual power increase is. For me the smoother running, better acceleration and much cooler engine temperatures more than justifies the work I have put in.
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Its a lovely bit of kit. In a world full of rubbish cheap parts its a real change.
Just comparing the number of flutes on the two filters appears to indicate the original has 60 and the new one 15. That would suggest that the new filter has a quarter of the surface area of the old one. It would be interesting to know how a filter with such a reduced surface area can have a better filtration combined with better air flow. I suspect it has something to do with “absolute filtration” and “nominal filtration”. Does anyone know the answer? Cheers Phil
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I had K and Ns on my SP111 which were great but don’t fancy touching my cali with injection and electronics.
I really can’t see how a filter can have better airflow and better filtration- it’s normally one or the other.
I know these performance filters use an oil coating with the idea that catches some particulate by sticking to it, but after x hours running there must be a loss of this function. Cleaning and re-oiling would help but I’m too lazy to do that as often as I would want to do I’ll stick with the paper ones.
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There is very little, if any, scientific evidence provided by any of the “performance” after market filter (oil and air) suppliers. They appear to rely on customers “feeling” that their purchase has improved the performance of their given vehicle. If they were so good then why don’t motor manufacturers use them as OEM parts. Can anyone reading this point me towards scientific proof of “better flow in conjunction with better filtration” for any of the well known aftermarket performance filters?
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not disagreeing with you about the lack of evidence regarding air filters for normal use (for racing I’m sure there is data collated by teams) but the simple reason manufacturers use cheaper parts is because they are cheap 
e.g. non braided brake lines, non stainless fasteners, lower quality tyres.
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i have a 125 that has a foam filter and the maintenence for this is to lightly coat in oil.
replacement OEM filter i bought looks no different to the original 2006 issued one (except it was dry ofc) and had to be oiled before it was fitted to bike
I haven’t actually felt any benefit from an airfilter change since i took the old pancake ‘filter’ off a 1971 BSA 500… and that benefit was apparently because the filter housing reflected pressure waves straight back at the intake.
I have fitted K&Ns - still have a pot of their oil. Also tried BMC & Uniflo it is an easy ‘fix’ so it tempted me.
But each time there was no discernible benefit so i stopped wasting the money.
Also many of the ones i fitted i could see through (yes after oiling) so not sure how many particles get through those holes.
I reckon they are probably brilliant for stopping rocks and pheasants so if i was racing…
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In all honesty, neither have I. I changed it because I have changed everything else and I wanted to do the comparison. The bike is a fantastic ride now, it was good before but there were aspects I felt could be improved. First and foremost the ridiculously high engine temperature that nobody will convince me is “fine because the engine is designed to run that hot” (it isn’t and never was) and the horrible low speed throttle response that is a result of running an air cooled engine that simply can’t shed the heat generated by running it so lean and then trying to force the hot exhaust gasses out through a totally restrictive exhaust system. The cat delete and the v-boost has effectively cured these two major flaws. The velocity stack was fitted as there is plenty of evidence that it improves the breathing of the engine. Overall I am over the moon with the mod’s I have made and with the possible exception of the DNA air filter, I would definitely make the same mod’s should I ever replace Goose with another v85tt.
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I have a V7 so not really looking at changing performance as it wouldn’t be able to stop if I did improve it 
. However, I am in the process of doing up a 1980 Honda superdream. The air filter is foam and then recommended by Honda to be coated with a light covering of oil. Does it make a difference? I don’t know and don’t really care but I’m doing it anyway. What I don’t understand is how, we as bike lovers and a dying breed, seem to get off on dissing each other over personal decisions. If you do or want a mod then great. If you don’t think it’s for you then great. Just please, don’t vent your spleen saying it’s a waste etc. If you ride the rattiest looking beast or the most splendid bike ever then I say well done and welcome. This is a Club. The hint is in the title.
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