View Full Version : replacing airbox with 4 individual filters. Pros/cons on EFI bike?

02-04-10, 08:53 PM
hullo team

just a quick ponder

whats the logistics of replacing a standard airbox with 4 smaller filters - on a EFI bike ?
Thought about it , want more intake noise and the look ( frees up a large chunk of room on the bikes mid section ). Im guessing it would be similar to a EFI car , that is increased intake noise and little gain , and the ECU will trim over a few tanks.

thoughts ? Its a commuter so its all for fun not outright times.

02-04-10, 10:21 PM
what bike?

02-04-10, 10:36 PM
cb400 2009

02-04-10, 11:37 PM
Look to choppers for ideas, they normally run velocity stacks out the side of the bike.

Not entirely streetable in my opinion. The airbox is there to protect the filters from the elements.

03-04-10, 12:41 PM
Not entirely streetable in my opinion. The airbox is there to protect the filters from the elements.

correct to a degree but thats the point of the filter itself.

The airbox is actually a major part of both sound ( remove intake resonance ) and exhaust ( via PVC system ) emissions control.

Ive seen it on a few project bikes via this "bike show off "thread and a few in other forums , it looks neat imo and wondering the overall effects. Anyone got em on a EFI bike ?

03-04-10, 07:33 PM
won't it make it run more leaner?

03-04-10, 08:08 PM
what about putting trumpets on the individual carbies and running filters straight from that?

03-04-10, 08:09 PM
ps. sorry for hi jacking ben!

03-04-10, 10:52 PM
Don't worry ray same theory !

As for leaner , on a efi bike it should theoretically trim alittle due to more air so perhaps run same or even richer. Apparently it's best to do an intake mid and muffler too the tune if carbies or adjust timing if efi more thoughts ?

04-04-10, 04:35 AM
hrmms wells i want a little bit more grunt out of it so ive been contemplating modding the airbox or the air intake part cos ive debaffled my can and i want to do the intake before i get carbies re-done so im not paying double? hrmms imo i think it would run leaner ben cos the fact that your having more air flow then before but with the same fuel doesnt technically mean its running leaner then before? ie. more petrol then air runs richer?

04-04-10, 05:58 PM
still on the cbr250 ? Your bike already has venturi's , 1 and 4 cyl. are short while 2 + 3 are long. They are rubber tho so perhaps you can make or replace with metal ones and get any old filters to suit. But , the location on the CBR250 would be very prone to heatsink at low speeds and traffic work.

As for my bike Ray - its EFI so automatically can trim the air/fuel ratio to a certain degree. Putting small filters on this bike would be similar to putting a air intake of a normal car. IE it will automatically adjust to a degree after a few tanks.
Ideally , you change the intake and you change the muffler or exhaust to free up flow both intake and discharge

04-04-10, 07:46 PM
ben, i'd recommend you look into a power commander if you want to fit the four filters. usually for the bigger sportsbikes, they come with air ram intake, so the only bikes which usually features ITB filters are naked bikes.

05-04-10, 10:09 AM
very interesting - thats essentially a piggy back computer ?
Just to let u know my bike is a naked too so it looks like the airbox takes ambient air not a snorkel/ram type arrangement.