
Before I get (dutch) approval on my car, the noiselevel must be reduced by 6 db(A). To reach this the open K&N airfilter must disappear for a
proper airbox. And there is where the problem starts. The stock airbox from my 2.0 EFI SOHC engine doesn’t fit at all. Now I’m thinking to use a
airbox from a small tin top. But would a small airbox from a small engined tintop get me enough air for the 2 liter engine. I ask this because I’m not
a car mechanic and out of ideas.
Ideas to get this noise problem fix are welcome. Greets Roy.
What about building some kind of casing for the K&N with the cold airflow entering via tubing. This could potentially lower the induction bark
which I presume is the problem.
Similar to this but more locost!!

I think you'll struggle to get a 6dB reduction with an air box given the space you have under the bonnet.
Since each -3dB is a halving of the 'heard' sound pressure level you'll need something pretty drastic to drop the level by 6dB.
My old granada, as do lots of fords, ran a 'resonator box' which dampened the sound - how about one of those? Its goes between your AFM and
the manifold - or mine did anyway.
If I were you I would concentrate on your exhaust to achieve that reduction in dB level - unless teh Dutch regs stipulate you must do something about
the airbox?
What exhaust are you running?
Geoff
[Edited on 11/3/07 by jambojeef]
How about putting the filter on the end of the blue hose? It would keep it under the bonnet and keep down noise.
You could even wrap it in foam to muffle it a bit more...
You'll be getting slightly strangled hot air but hey! It's only temporary....
How about a discreet grub screw to limit the throttle opening to 3/4, then only 75% of the airflow - perhaps......
Been to the local scrapyard today and bought me three airboxes. The one from a Alfa Romeo is made from metal and for this reason easy to change. But
the best one to fit, the one from a Chrysler Voyager V6. And that one works. The intake noise is 6 db(A) less than the open K&N Filter. Tommorrow
I will make some brackets for the airbox.
Greets Roy
[Edited on 18/3/07 by dr-fastlane]
quote:
Originally posted by BenB
How about putting the filter on the end of the blue hose? It would keep it under the bonnet and keep down noise.