Anyone know what the deal is with this airbox?
I just pulled my filter to have a look and its ridiculous...

Also are there any mods that can be done to the airbox to improve intake sound?

I searched but either terms are too common or I came up empty.... search sucks....

 

some members just removed the air reservoir lid. Its right above the intake inlet. I tried this but it was a little too loud for me.

What I did is drilled out the side of the reservoir lid instead of taking the whole thing off. I cut out the side just above the intake inlet. Now essentually it pulls air from the under hood scoop through the intake inlet and the reservoir box opening. Probably helps the car breath a little better. This gave the car a deeper growl to it but not too loud. Don't think it does anything performance wise but with my K&N drop in filter it sounds a lot better imo.
FYI I ordered a new lid in case I didn't like it...just to be safe. New lid cost $7 at Bernardihonda.com.

 

Ok yah I just pulled that off to look in there and was thinking the same.

Looks like a good spot too the air vent is right there...

Thanks...

 

Could you post the part number of what you removed/drilled or take a picture of your mod? I'm not visualizing it.

 

Sure its part #3 in the picture. I circled the side I cut out.



Here is where I got it from...
http://www.bernardiparts.com/searchoptions.aspx
sorry it was $7.71

Part # 17202-RB0-000

 

I drive with mine off. Sounds and runs fine.

 

Can someone explain the logic behind this multi chamber intake path? I mean, it looks like nothing I've ever seen before and makes no sense. It's like the least direct air path I've ever seen. Why don't they just have an orifice go through the airbox/filter then into the intake manifold? It seems weird there are all these extra caverns.

 

Some people would complain about the noise of the engine if they made it a direct path intake. Many people want a car that's dead silent unless something is wrong with it.

 

Yep, always a balance between power and sound level. Maybe the door on the chamber was intentional, so those who don't care about sound level can take it off to get a bit more power. Who knows

 

That's not bypassing the filter is it? It's late and I really shouldn't be up....>.<

 

IIRC, that plenum box is upstream from the filter.

I don't know why the convoluted multi chamber design unless it's to provide sufficient airflow silencing in the minimal space available.

 

^^ there you go.

My civic had something similar, it was a big box that didn't do anything but try to act as a pressure buffer, and when I took off that big plastic box, it was loud. I put the plastic box back on, and it was quiet again.

Keep in mind that I didn't remove anything other than the box at the very bottom of this picture:

 

Well I guess the thing does it's job, because you can hardly tell the thing is running when idling. I may try taking that hatch off next week. I've got a nice weekend planned in the M Coupe with some end of season autocrosses complete with lots of engine and exhaust noise.

 

Where are you racing?

 

I drilled 3 3/4 inch holes in the side would have gone a little bigger but all my paddle bits are at work.
Still silent at idle but has a nicer tone at wot.... not loud enough for me though Im going to try without it today.

 

You can cut the baffles out or replaces it with an aftermarket intake. I don't mind it too much though.

 

I'll try without it today on the way to my work.

 

I took off the cover last night, and drove to and from work today, mixed driving. WOT was louder than usual. I couldn't really feel any openings that passed air, figured it was a resonance box.

 

It does draw air you can feel suction from the holes I drilled...
and if you shine i light from under you can see it faintly very odd path though..

Anyways I drove around all day today with the cover off... sound was a little louder but also a harsher sound think ill drill a 4th hole and replace cover...