A bigger airbox should help power if things are set up to match it, the increased volume helps slowdown the air in the airbox thus (wow i used thus in a sentence) increasing its pressure(slightly). Greater air pressure means more more fuel can be burnt and thus (wow thats twice) making more power.
Its simliar to the effect of riding on a hot day, and riding on a cold winter day when things feel much crisper( if you know wat i mean).
Cheers
Ian

Yes, I do agree on all these valid points but for it to show anything on a dyno it needs more than 8% and also a fresh air feed instead of dead engine air.

Stickshift I agree that it Might improve throttle response but does it increase in the same way my arse dyno tells me that the HRC ignition is better than the standard one but wen tested it showed less power? I would say coupled with a much bigger increase in volume or a ram air snorkel it would work best .
I know it all sound good on paper but if it works then I will defo get one, anyway I spoke to Paul about the air box a while back and he said that its not to be used with the air filter as it doesn't fit its meant to be use with out, but alex said he's using the standard air filter . It could be that you could benefit from the 8% with no filter in a race setup.

Morespeedvicar wrote:A bigger airbox should help power if things are set up to match it, the increased volume helps slowdown the air in the airbox thus (wow i used thus in a sentence) increasing its pressure(slightly). Greater air pressure means more more fuel can be burnt and thus (wow thats twice) making more power.
Its simliar to the effect of riding on a hot day, and riding on a cold winter day when things feel much crisper( if you know wat i mean).
Cheers
Ian

isn't larger volumes of slower moving air = less pressure? Bernoullis principle?

The engine sucks the air in, it is not forced in. Having a larger, relatively placid air supply could allow a more efficient gulping of the air by the motor which is why this is better..

What do you say to that?

Amen to that now that means the engine is less laboured and would show better response like Stickshift said

I have no doubts that a bigger tyga airbox setup to run no filter on hrc rvf carbs would be something though, gain the best of both worlds - no restrictive filter and larger volume.

I think that you'll see minimal gains if you use an air filter. But they do look hot!

Yes they do I've seen a carbon kevlar one before with a ram air scoop and that looks great to can't remember who makes it though

I'm with you Mark. To increase the internal pressure surely you'd need a smaller air-box. I really can't see the 8% increase in volume doing much for pretty standard road-bikes, but maybe for a ram-aired race/track bike (although, when I ran my trackbike with ram-air the standard air-box seemed more than capable)

If it were me, I'd be looking for one of the airboxes shown on Yahoo! Japan (similar to the ANR ones)

Based on the discussion I have had with my tuner...

You also need to take into account the helm-holtz (dunno about spelling) principal in the airbox.

Same as for an exhaust there is a resonance related to volume (and length) that causes the pressure wave to bounce (We've all seen our carbs spit fuel into the airbox). In the exhaust you use it to assist in sealing the charge in the chamber, while on the intake side you take advantage of the inward pressure putting more air into the intake carrying the charge with it. This is partly why ram air setups and open carbs are so difficult to tune - because the volume is always different based on the surrounding air pressure, speed, side wind, etc without the air box there is nothing for the pressure wave to rebound off effectively.

Air box volumes are just as tied to engine tuning as the exhaust. The engine breathes by creating a negative pressure inside the airbox, sucking air in, and uses the rebounding pressure wave moving into the engine to carry a poofteenth more of everything. I think this is where variable intake lengths come in, allowing you to take advantage of the pressure wave over a wider rev range.

Thats my understanding.

yes, heimholtz IIRC.

this is why the HRC intake stacks are shorter as they hav a shorter wavelength frequency and are more efficient at higher revs..

Yes your right its Bernoullis priciple, but air pressure goes down with speed, a good example is airplane wings, air going over top of wing has to go further than air going under it( because of its shape) so has a greater velocity and less air pressure, and is sucked upwards( or pushed up because of air under the wing having more pressure).
You have to think of carbs sucking in air from its surrounding area, if the airbox is small, the atmospheric pressure is always trying to be filling in this space but will never have time before the engine sucks another chunk of air in, when it becomes a restriction, if theres a bigger volume if has more time( so the gas is going slower and has a higher pressure) to fill this space before the engine sucks again.
Heres a link to some thery.
http://en.wikipedia.org/wiki/Bernoulli's_principle
Bigger airboxes have been fitted to race bikes for years(ZXR750Rs and one of the 916 shape ducatis spring to mind) in a hope of getting more power, this and trying to match resonant frequancies, and ram air effects. All very worth having, as its it relativley easy and cheap to achieve, and its much better than not having it at all.
Hope it makes some sence.
Cheers
Ian