Bi Modal Air Intake

[galahs]

if you take the air filter out you will see an opening leading to another box that has a vacuum actuated valve. look through the grille openings under the lhs headlight and you will see it is open, that is where the bi modal grabs the extra air from. the rhs is actually blocked.

Interesting as the GTS doesn't have that grill opening, but it does seem to have one above its lhs fog light.

So surely some people have actual pictures of the bimodal system by now.

 

[galahs]

Well I found pics of the bi-modal air intake and quite frankly, they aren't that impressive.

The pipe that feeds the airbox doesn't get any bigger. Just the opening to the atmosphere.

 

[PIR4TE]

Well I found pics of the bi-modal air intake and quite frankly, they aren't that impressive.

The pipe that feeds the airbox doesn't get any bigger. Just the opening to the atmosphere.

Good work, thanks.

Looks familiar, I wondered what that trap door felt thingy was on my intake:

The trap door actuator is a servo motor, can't see the connector.
Food for thought, thanks.

 

[vongy10]

So the trap door felt thingy just makes the induction noise louder?

 

[PIR4TE]

So the trap door felt thingy just makes the induction noise louder?

I think the aim is to let ancillary air in, like an air dam. The trick here is it is controlled by the ECU (via EDI) to open at certain revs. Yes it would be louder too. Not as loud as an OTR trumpet though.

Sorta like the one I got but mine's unimodal:

Nah, not rocket science :yarr:

 

[captain_slow]

There's vac operated flaps on the intake into the airbox on the Honda SP1/2 (had an SP2), the flap closed at high rpm to reduce the amount of charge air available to stop the motor leaning out. Granted it's a bike and had a decent size hole directly into the front of the airbox, but is it potentially the same thing? Faster air means more of it and it could be to gain more efficiency, by not running lean, and thus more power out of a motor?

 

[PIR4TE]

^^ interesting but it's not a dump valve rather the opposite. The throttle butterfly regulates manifold pressure, and the Honda flapper is all about noise control:
http://www.rc51.org/valve.htm

 

[captain_slow]

Was just a thought on what a flap upstream of the throttle body might be for in a bi-modal intake. The Honda had 'ram-air' or whatever proprietary gimmick name they gave it too, which might change the dynamic of the intake tract enough to warrant such a thing.

Just quietly though, noise control on a bike that a lot of the time had a set of yoshis or akras stuck on it lolz, wide open throttle and the missus could hear me coming home when I was 5km away..... Those things were loud lol