y8s

iTrader: (8)

it smooths the transition from earths atmosphere to your intake pipe. when air bends around sharp corners at high speed, it makes noise.

JasonC SBB

Yup, and if you're on Mars, the atmosphere is thin enough that the noise won't bother you.

Doppelgänger

iTrader: (12)

Wrong. It's put on the inlet to turbos to make them look bigger and intimidate the guy in the Mustang who wants to see your engine before making some highway pulls. Gosh..get it right Matt.

y8s

iTrader: (8)

if you're on mars and sucking in earth's atmosphere, you should put up with the noise.

miata2fast

iTrader: (2)

Fixed

fooger03

iTrader: (2)

This thread makes me laugh, it has brightened my day

OP - post pics of engine bay

richyvrlimited

iTrader: (1)

Yeah, I kinda expected ribbing, I've done the same myself in the past when someone has asked something similar, but I'm older and more irritable now

Picture:


Note the airfilter is now near the headlamp lid and the pipework follows the wing (in an attempt to lengthen it and reduce the noise.

y8s

iTrader: (8)

the corrugated tube aint helping...

richyvrlimited

iTrader: (1)

It's gone now

Why doesn't it help? I've heard anecdotal evidence that it helps!

richyvrlimited

iTrader: (1)

double post

fooger03

iTrader: (2)

Ribs create friction, friction causes resonant turbulance, energy lost to turbulance is converted to sound and heat.

Your original post suggests that you are trying to combat "whine" instead of "whooshing" - is this correct?

richyvrlimited

iTrader: (1)

yeah reduce the whine, It must be possible as my old mans car barely murmers (granted it's a smaller blower spinning slower but still I don't expect silence, just a nice reduction).

JasonC SBB

The fact that whine is a higher frequency than an exhaust or intake note, should make muffling it a bit easier.

240_to_miata

iTrader: (2)

Look up a helmholtz resonator (spelling??) . Ever noticed some stock intakes have a random tube that leads to nowhere and dead ends? This is a helmholtz resonator. It cancels out a specific frequency very well. If you do your research you will find some simplified equations which will give you tube length based on wavelength. Of course you would need to know the frequency that the noise is at before you could cancel it.

fooger03

iTrader: (2)

rebuild the supercharger

JasonC SBB

helmholtz resonators work over a narrow freq range. They don't work well if your 'charger whines from 4000~7000 engine RPM.

Broadband absorbers work over wider ranges.

240_to_miata

iTrader: (2)

true. Most acoustic resonator style sound cancellation techniques are "tuned"

richyvrlimited

iTrader: (1)

Yeah err it's not that, it's been completely stripped and rebuilt very recently.

Doppelgänger

iTrader: (12)

Just yell at it to shut up when you're driving down the road...



Ahhh you make me think about the unthrottled M45 I had and how it sounded like a firetruck coming down the street

pdexta

iTrader: (17)

Maybe something on the underside of the hood? S2000's have a foam pad thing on the underside of the hood which definitely helps to surpress engine noise. Something like that would certainly help (as long as it isn't flamable).