Already tested, doesn't do anything significant:
Project S2000: Part 20 - Stock Air Box Modifications And Not Going Faster

 

Did something similar, I designed a NACA duct to use for ram air:
Project S2000: Part 19 - Ram Air!!! Plus Hot Air Testing!

Slight fault in my setup in that I didn't plug the hose going to the front breather of the valve cover, so I was blowing pressurized air into the valve cover.

Next time at the track, I plugged that hose and gained some more pressure gain.

Project S2000: Part 22 – Testing New Goods and More Intake Mods

 

Nice test by MotoIQ , I agree with them that feeding cooler air is about all you need to do, as my ap1 ran great with the oem air box and a snorkel

 

^^ Its all there in black and white

 

Guess my first instincts were my best instincts. Anyone need a spare airbox? If so, shoot me a PM.

 

I recall reading thay excellent motoiq article on more than one occasion. Well done.

In that article it was noted that after internal airbox modes revealed no real difference in air pressure (read, no relief of any restriction), a test with airbox lid removed showed a real improvement in this area. Of course, the overall effect was a big loss in power, since as everyone knows it also allows hotter air into intake. One step forward, three steps back.

But what this shows is there IS still an airbox restriction. That small rectangular intake opening at the front of box. Bigger opening would be an improvement (Honda probably didn't make it bigger to remain compliant with noise targets).

The idea proposed here is to add a HUGE 6 inch hole in the lid, along with an elbow that would act as a scoop (as a prototype. If it works then a hood with a decent looking scoop would be fabricated). The stock rectangular front opening would be blocked off.

The stock rectangular opening is probably equivalent to something around a 2.5" hole (I did the math once, this is what I recall). So a 6" hole is much more than twice the size of stock opening. It has the added benefit of coldest air possible, and no added twists or squeezing through narrow sectuons like snorkels added to fromt of box have to deal with.

So the proposal should yield measurable improvement in intake pressure. Whether that translates to measurable power increase is another matter. Perhaps Honda found it added noise and only a little power. We might prefer them both. So I'd still like to see what results.

 

And claims they've confirmed it on the track. Can't tell anything from their dyno test as they also have a Skunk header (and they're on a DynoJet which is hardly conservative).

-- Chuck

 

Note that he didn't say specifically that cutting the divider added power. He does state the wall is part of the noise suppression of the air box. He stated clearly that blocking off the hole to the resonator only changed the sound, but didn't change power. I feel like he includes the K&N air filter as part of the 'stock airbox mod' and that makes power by reducing intake restriction. The dyno is of a header, K&N filter, and Hondata tune.

 

I don't see anything wrong with the oem air filter either, it has a built in air horn and is more than large enough for the size of the engine, and filters better than cotton gauze filters IMO. I recall Xviper (Dave) once stated that the S2000 filter had more surface area that the two air filters on his Viper combined.

 

Yup, stock Honda OEM air filter is MASSIVE. The only way to reduce restriction is to reduce filtration efficiency.