Induction noise - reduction methods
 

Does anyone have any good solutions to reducing inlet tract/induction noise?

I have (for my sins yadda yadda) an MP62 which whilst sounds nice when in the mood at WOT is now starting to get on my nerves when just trying to commute.

I've had the car for 7 or so years and the charger setup for 5 or so years.

I have an A/A IC fitted, but in order to stop idle droop and awful throttle response I've had to fit a dual throttle body setup which works great, the downside is a tendency to cause the charger to whine at part throttle.

So long story short any tips to reducing inlet tract noise? FWIW if it costs a bit of power I'm ok with that assuming it can be reversed when on track (so no smaller pulleys).

I've tried lengthening the inlet tract to the charger considerably with very little/no effect.

Thanks

My supercharged miata has the tb in the stock location so the noise is probably similar. Here is my solution for commuting.

Attachment 191527

try to fit the stock airbox back on the car?

Yeah, he might as well remove the supercharger while at it.

Had thought of the stock airbox, or at least part of it, and building a glass-fibre enclosure for the OEM panel filter but there's just no frigging room at all :(

My dad has an M45 Coldside which I've DD for the last week, and there's virtually zero induction noise, it was bliss, his cars induction tract goes from the back of the charger, under the inlet manifold and then to the front of the engine and is mated to a JRCAI kit, I'd ape that if I could but don't possess the skills, nor have the room he does.

RE: a different car for a DD, I'd like to but can't afford the £$£$£ :(

this.


Based on some of the rather complicated OEM intake tracts I've seen, it seems some fluidics engineers are working hard to keep modern cars quite. I don't think there's a simple solution (such as lengthening the path).

An air box should help in quieting an noise caused by the filter itself but it probably won't entirely 'resolve' the noise as I assume much of it is coming from the 'charger.

-Zach

A muffler of some sort will help some.
Look at how straight thru mufflers are constructed. The pipe has lots of holes, then it's wrapped with sound deadener, then sealed...

maybe different types of intake filters?

the y8s perfect quiet high flow intake consists of:

a trumpet style 3" inlet that leads to an airbox with a large panel filter which leads to your throttle body (or SC). if there are any droning intake frequencies, you can add helmholz resonators off the post-filter inlet pipe to shut them up.

of course the OEM 2001 intake pipe is exactly what I've just described except for it isn't 3 inches in diameter.

I thought that intake tract noise from a hot rod was a good thing. Are you guys going soft on me? :jerkit:

noise is annoying. you dont have to sound like a honda to be fast.

^^ this

Thanks y8s, I'm going to have a play fabricating an airbox and use the OEM panel filter, fingers crossed it has an appreciable effect.

FWIW one of the members on MX5Nutz has an enclosed 'carbon' filter, like the type BMC sell, he said it cut down his intake noise a lot, especially around idle/cruise.

http://www.amazon.com/Spectre-8788-U.../dp/B0008FUHJ6

http://ecx.images-amazon.com/images/...VL._SS400_.jpg

Install sub woofers

I suggest oem airbox = no one gives a shit.
others suggest it a few posts later = idea of the century

I give up. lol

i suggested emulating it, not fitting it back on.

Fit an empty 2 liter bottle with a hose attached to the intake!

http://www.boostedmiata.com/gallery2..._valve+008.JPG

I swear it works.

http://forum.miata.net/vb/showthread.php?t=285960

http://forum.miata.net/vb/showthread.php?t=235997


LMAO @ douches getting all pissy about the induction noise of a turbo.

I've actually thought about stuffing my cold air box... my intake is loud.

My thoughts exactly.