Resonator or Silencer

[Gumby]

Anybody know much about resonators?

I have to have the car tested by the EPA for noise, and not sure whether to go silencer or resonator. It needs to be effective to the tune of about 8 - 9 db and I want whatever would sap the least power. if anybody knows, much appreciated.

P.S. They tested SPL at 5,000rpm, sounds high to me, wonder if anyone knows if this is the correct method of measurement or were they just trying to be a pain.

Thanks.

[franks]

had a friend in a similar position, he got his quitened with a resonator, apparently its a straight through pipe with carbon in it!? supposedly quieten's things down dramatically with very little restriction!? worthwhile probably talking to someone who is in the exhaust field though.

silencer won't hold water afaik. they must be *permanently* secured to the exhaust. silencer can be made up and tack welded in though? probably better off going with the resonator?!?

unsure of the correct method of measurement for loudness...i know its 1m back or something though!?