I understand that it might reduce the amount of hot air coming into the air box. By connecting the filter/s directly to the current pipes that feeds the airbox oil catcher tank oil will just pi55 out. if anything it looks cool on this particular bike, but im just baffled at the purpose.
There's a long and lengthy discussion on them here Yes it's a Triumph forum but is may offer some insight. Any gains to be had would be minimum so mostly bling really.
Benny Hedges had a home made set up like this on his modded airbox.
The breathers purpose is mainly due to emissions control but an engine needs somewhere to release excess pressure otherwise it will build up like a pressure cooker and blow seals etc.
thanks for the info Carl, ill have a read up. I am not interrested in putting one on my bike, ive just seen a few bikes with them and want to know how it works and the reasoning behind it. The more I play with mine and see what other people do to theirs, the more I want to know and understand. Just find it facinating
Hawk is another one I think is airbox experimenting with things at the mo, so constantly changing things about. I'm sure he will have something constructive to say on the subject when he's back up and running with us. I believe Tony is running the same/similar set up though his keeps changing as well
Interesting subject and ties up with the whole airbox modding thing so a bit experimental with regards to any power gains and where they may be. It's also going to be different for a standard engine compared to tuned. We all know how these bikes like having the airbox messed with But I do like the idea of tidying things up a bit inside the airbox.
The one in the pic adds to breathing through the oil filler hole, the ones that I and others have been playing with are the two pipes that exit from the cam covers and end up in the airbox.
Removing things form the airbox always seems like a good idea; it will allow cleaner flow, more volume, and that can't be bad.
There is a tiny power gain to be had by reducing pumping losses, and the one-way valves will also reduce crankcase pressure to a bit under atmospheric, so again a slight benefit.
But I'd be very wary of fitting a cone pleated filter like the one in the picture, as they let rain in as well as air out, and you can easily end up with mayonnaise gloop in the tubes leading to the filter.
If fitted like the picture one it will just drain straight into the engine.
I used clear tubing so I could see an build up, and ran it via a dip in the tube where it would collect and could be seen (and removed) before it got to the engine.
A vented catch tank it going to be a safer bet.
It's not falling off, it's an upgrade opportunity.
But I do like the idea of tidying things up a bit inside the airbox.