PDA

View Full Version : Sound Levels?



07-29-2001, 02:02 PM
Can anyone tell me the decibel levels of the aftermarket silencers along with what it is stock on the 400ex. I believe it told it in one of the 4 Wheel ATV Action magazines but I dont have that one. Any information would be greatly appreciated.

Leo
07-29-2001, 02:30 PM
compared to the stock silencer they start at really loud, and go up from there :o

Leo

07-29-2001, 02:33 PM
I want the numbers not a description please?

Leo
07-29-2001, 02:44 PM
#'s can be very misleading, noise in a controlled test, and noise when actually riding are two very different things...

I have the advertisement, er.. article that was in dirtwheels I'll see if I can dig it up later tonight :square

Leo

400exRacerX
07-29-2001, 06:48 PM
the stock exhaust pipe is at 88 decibals. and the white brothers s bend pipe is at 95 decibals ( wich is fairly low compared to other pipes). But even though the WB pipe is only 7 decibals louder, its alot louder. heres a way to give a good example. its the difference in sound between a car and a harley. even though 7 decibals it sounds 20 times louder to the human ear. there is no quiet aftermarket pipe.

EX_RIDER
07-29-2001, 09:04 PM
DELETED BY ME

MISTAKE
My pro meg is 104 at like half throttle!!

NVR2L8
07-29-2001, 09:09 PM
I have never seen a comprehensive list of pipes and thier respective decibel ratings, although a guy on ATV Connection was working on one quite a while ago. Don't know what ever happened to his list... At any rate, 88 db's sounds about right for a stock silencer, and I'd guess an internally modified stock unit would be about 90 db's. As a side note my new FMF Power Core IV2 "Q" silencer is pretty quiet...just a tad louder than my modded stock pipe at idle but more so when the rev's build up. My guess it's around thier advertised level of 92-92 db's.

400exRacerX
07-30-2001, 10:15 AM
and what did you measure your pipes sound levels with? not to start trouble but i find 104 at idle hard to beleive and 120 at half throttle is extremely hard to beleive.

EX_RIDER
07-30-2001, 02:52 PM
I know the measurements are right!!I used a digital sound level meter.Measure 20 inchs from the end of the exhaust and at a 45 Degree.I also had a shop place do it after I did it and they got the 104 also.You also got to remimber i took out the blank disc and the exhaust comes straigh out and exxo's.I also am doing this on a hard dirt road and that may change it some!I will go out tommorow and do anotehr test to see what I get.

EX_RIDER
07-30-2001, 02:57 PM
http://www.oohva.org/

go to that site and go to honda's.You will notice that the white brothers pro-meg exhuast is one of the loudest in there!!

07-30-2001, 03:47 PM
what's the db's of a stock w/o the spark arrestor?

just so I have an idea of after market noise, cause i've only heard stock and no S/A through all revs.