Our rule book states you have a choice from three air cleaners to run. They are parts:
Briggs & Stratton Green Air Filter Part #555729
Briggs & Stratton Green Air Filter Part #555758
Uni Filter Foam Air Filter Part #UP4112A
The first two are Briggs paper / element filters and the Uni is of course oiled foam.
Has anyone dyno’d or live tested between the element and foam filters and found an advantage in flow?
Somewhere I’ve seen a video of a Briggs element filter that has let through a heap of dirt. Not sure of how long it was on or anything, but just looked super detrimental to engine life.
Oiled foam is a go-to for dirt bikes so I think it’s going to do what you want. The oil they use is very sticky so I’d imagine that thing it going to look terrible after a day at the track. I wash my dirt bike filters with dish soap then re-oil.
the briggs are a oiled cotton filter produced by Green filters. Same as a K&N, just with green oil. Lots of guys run them without oil, but I always oil mine. They seem very clean on the inside so I’m not seeing any dirt get through
I would imagine that any flow difference between the filters would would make no performance difference because it should be far and above the flow needed by the engine
One thing I have read is that the orientation of the filter can make a difference. Have not tested that myself, but it’s an interesting hypothesis.
James is spot on. The air cleaner flows more than the engine could ever fit through that tiny carb so it doesn’t really matter. Back in the Ghost Racing days, we did test air filter orientations and found some slight differences (not enough to make me move mine on my personal kart), but never made it to the chassis dyno to test them truly with ram air.