what does a resonator do?

[ericn1300]

My daughter wrecked the front end of her 97 CRV and the body shop just called to tell me it missing the resonator, that it's a Honda only part And cost over $100 for a couple of ounces of plastic. What does it do? I think it was missing when we bought the car.

[CivicSpoon]

It pretty much just helps to muffle the sound of the air intake. Either removing some of the raspy sound to it or reducing the volume of the sound in general.

In this pic, I'm not sure if you're (or they're) referring to #14 or #13.
http://www.hondaautomotiveparts.com/...y5=AIR+CLEANER

If it's #14, then tell them to forget about it, and just plug the hole in the air flow tube when the vehicle is returned to you. If it's #13 (the "Muffler"), then it might be an issue of not having anything to connect the air flow tube to the air cleaner box. It appears to have an oval shape on the air cleaner box, verse a round shape of the air flow tube.

If it's neither of those parts, and is attached to the bottom of the air box (past part #12), then it might help against sucking up water into the air box as well.

But any way, you could always go to a local car parts lot, and probably find the part there, for a few dollars, rather than spending that much for a brand new part.

[ericn1300]

well that exploded diagram doesn't even come close to our vehicle but you're probably correct in noting that Item 14 is probably unnecessary as it isn't shown in the parts list.

[CivicSpoon]

Ohhhh. I guess I should have checked the other sections on that site. Here's the resonator, or at least what the site says it looks like:
http://www.hondaautomotiveparts.com/...HAMBER+%281%29

Seems to ensure that water doesn't get into the air box as well, at least the combo of resonator and tube. But it would cause a major restriction to air flow to the filter. Most people I know with Hondas just remove them on their cars anyways. Certainly not the safest option, but plastic "skid plates" (or whatever they are called) should do most of that job anyways. Then again, if the Air Intake Tube (#5) is there, then I wouldn't even worry about it. The chances of water getting in to that hole on the side, isn't very likely.

Strange that the picture doesn't match the vehicle though. There's only a selection of with ABS or without on that site, and those pics are taken from Honda's own parts program.

[ericn1300]

yep, that's the resonator, no one seems to know what its for but the body shop noticed it was missing since it actually has the brackets that hold the air intake tube in place so we replaced it.

I found this on a google search that might explain it:

" Most resonators have a dual function. They can help reduce intake noise but also create a helmholtz resonator. This is a GOOD thing for performance and can actually provide a slight hump at a particular frequency.

I think it's funny that people remove them and then wonder why their whp numbers actually dropped many times. Don't let your ears fool you, louder doesn't mean faster.

I know what I'm saying might be foreign to some, but this is something myself and many others learned years ago when getting into real technical things with performances on B18C engines. The same physics will apply here.

Helmholtz resonance - Wikipedia, the free encyclopedia

...so unless you're replacing it with something else (CAI, Icebox/Mugen, etc.), I'd reconsider the removal of it.
__________________
www.itrexpo.com "