I can say it does make a difference i got more response at speeds above 30mph i can feel the difference and i also get better gas mileage 3-4 more miles per gallon i have the oem navi. And on there i have fuel economy readings and usually get 19.5 streets and 24-26mpg highway with this air flow mod iam getting 22 street and 28-30i highway. I guess if people are looking for results to see if this does anything there u go.it does make a difference Thanks again to the guy who posted this DiY. Simple easy mod tht cost 12-14$ cant complain. And again ill use the same concept with my cold air intake set up but of course ill add air bypass valve to prevent water intake

 

I have found another way to open up the stock airbox no mods costs 0$ take this plastic piece off and note the hole its a 4" pop charger and can be reinstalled for the winter. no drilling been on for 2 weeks all good!

 

if i tried this down here in hawaii id have a hydrostatically locked motor.

i agree with wiredG35

 

heard of a few people doing this with bigger piping nice!

 

there should be no hydro-lock since there are still two other openings to your airbox, and thus not enough suction to pull water up.
i obvously saw that the large piece there, shown by Wired, could simply be removed. I chose not to do this because that opening is still inside the engine bay, sucking in hot air especially when at idle.
the original modification pulls air from out front of the car, as has been discussed in this thread ad-nauseum. It also acts as a collector at-speeds, whereas the hole inside the bay, is not directly in any stream of air.
hot air, and no injection at-speed, in short

 

I actually cut a piece of foamboard in the shape of the baffle, to close it off from the flow
i snapped these photos

 

damn thats a sweet mod now could you cut the piping and insert a small filter to be as a bypass just incase water is sucked in?

 

If you don't close off the main 2 inlets you shouldn't have any problem with water, not enough suction to pull water up the tube

 

I did mine today but with only 2 inch piping and i dont hear or feel a difference.

 

I did this with my integra, same principle. I used 4" pvc pipe from the bumper to the air box with a 4" speaker port at the opening to act as a velocity stack.

To prevent hydrolock, I drilled a 1/4" hole at the bend of the pvc pipe. The opening of my air intake was at the lowest point possible, the only thing between it and the road was a splash guard and my integra is lower than my sisters G. I have driven through countless rain storms and the engine didn't hydrolock.

I don't know about the g, but my integra did gain noticeable power above 3k rpm.

 

For those who are so worried about hydrolock why not install a electronic irrigation shutoff valve in line to a switch in the car (also would eliminate rodent infestation worries)

 

This is just a hobby lobby mod that we don't really talk about anymore .

Your car naturally picks up from that area in the design of the OEM intake.

 

Well it is something that is interesting to me and with improvements could be a viable ram air intake

 

I did the same, however, I went crazy and used a 4" flex pipe. I used a sealant to fill the gaps in the air box and netting from an old gym bag as a shield to prevent leaves from getting in there.

 

Did this today. No ace hardware, so I opted for Home Depot. A few bucks less and some trimming had the set up working. I used the original posted sizing of 1 1/4 piping and a larger flashing that was trimmed down some. I placed a extra coupler on the 45' pvc to keep the flashing stabilized. In doing so the coupler extends a few inches past the flashing but because it's larger (4 inches trimmed down to near 2 1/2 -3ish range) it sits in the middle. Not sure if it effects air flow but because everything is behind the bumper I cant tell if the air draw is effected negatively. I may play with it some more. 1 hour of driving was ok. After that, I had a questionable idle at the light but then it smoothed out. So far I enjoy the feel from the butt dyno, however hp gain testimony is not available and probably won't be provided due to it being a filler mod not a major hp gain source.