View Full Version : Should this piece be removed from the airbox?

07-24-2009, 10:51 AM
So I was cleaning out my air box and noticed the little insert that is glued into the air box cover and has less opening than the outside of the airbox. this looks like a pretty good restriction to me and made me wonder. When I got the bike from the previous owner he told me it was derestricted. He gave me the rubber boots from the inlets and the cones from the exhaust. I know that the work was done by Allen Noland also it would look to me like this piece should be removed for maximum air flow. Allen did tell me that he installed the latest map from Aprilia for derestricting.

Should this piece be pulled out?


07-24-2009, 10:55 AM
Those pieces stop water going straight into the airbox. Lots of bikes have similar structures in their induction system.

07-24-2009, 10:58 AM
That make sense. It just struck my curiosity with how it is set up.

07-24-2009, 11:15 AM
you should replace the whole top with a Pipercross filter.

07-24-2009, 11:20 AM
...it would look to me like this piece should be removed for maximum air flow....Should this piece be pulled out?

If you do decide to remove you should cut above the filter surface and not just pull the whole thing out as others have done. That piece is a functional part of the air filter seal surface. Put the filter back in and look closely. With that piece completely removed there is a direct path around the air filter to the inner airbox. I believe the K&N filter instructions mention it as well.

07-24-2009, 11:56 AM
You are right. I can tell where the filter sits along the edge. thanks.

07-24-2009, 12:28 PM
I removed the lid and replaced with AF1 blue filter.

07-26-2009, 08:06 AM
i cut the whole top off of mine and run a k&n as for water sure but it hasnt been a problem and most of the astermarkets eliminate the whole top...my wr had bunch out things like that as well part of derestriction

07-26-2009, 10:35 AM
I was told by AF1 that they take them out. As mentioned above it is however a functional part of the filter seal. I used the twin air with the part removed as the filter seemed to fit better without it and it did not seal well . I quickly changed the filter to a AF1 dual foam. With the K&N the filter fits well with the part in place. I really like the AF1 filter. I have used it in very dusty conditions without a problem. I will stay with that and perhaps the K&N in the winter. I wll be selling my twinair foam if anyone is interested in it.