2006 WR450 Exhaust Sound Level Tests

[Beef]

Does anyone have any exhaust sound level data on the stock 2006 WR450? Specifically, with and without the 1/2 inch restrictor in the tip?

[Jah WR]

The 2005 with the small inner baffle (the one riveted in place) removed measured ~93 Db. Regardless of the exact sound level, you can be sure it is below the 96 Db threshhold for open course riding. 2006 is no different in exhaust system design.

[Beef]

Some of the places that I ride require 93dB or less (ie. Oregon Dunes), so I definately need to be well below the 96dB limit at times. How confident are you that the stocker is around 93dB with the cork out? Do you have any idea what it measures with the cork in? I have an FMF Ti-4 for riding wide open, but sometimes stealth is good.

[yz250ftony]

FMF q2 is 93 and under.

[Beef]

I'll probably end up with the Q2. For now, I'm in the process of coming up with enough cash just to buy the bike...so buying a new muffler right now isn't in the cards. If I can make due with the stocker for a while without getting a fine, I'll be fine. ?

[mtrablue]

FMF q2 is 93 and under.

don't bet on it. the five valve yamaha is hard to quiet down and still run. i've got a Q2 on my '03 and i really doubt it'll comes close to 93db. (don't let any body tell you the Q2 will turn your wr into a freak'n rocketship either) don't sell the stock can short. try all the free mods with the stocker before you shell out any more money. 93db is pretty darn quiet, stock may be your best bet one way or another.

[Jah WR]

Some of the places that I ride require 93dB or less (ie. Oregon Dunes), so I definately need to be well below the 96dB limit at times. How confident are you that the stocker is around 93dB with the cork out? Do you have any idea what it measures with the cork in? I have an FMF Ti-4 for riding wide open, but sometimes stealth is good.

Dirt Rider magazine, in a test of the 2005 last year, quoted 92 Db with riveted-in baffle removed. So...., you should be in pretty good shape. On my 2005, I removed the tail pipe as well and installed a Pro-Moto Billet Insert. Nice boost in power and still below 96 Db.

[Beef]

Thanks for all the great feedback. I think I'll probably just run the uncorked stock endcap when I need to be quiet, and buy a PMB endcap for the rest of the time. ?

[odonnks]

March 06 Dirt Bike magazine did a 450 comparison with sound level tests after these common mods

[yz250ftony]

don't bet on it. the five valve yamaha is hard to quiet down and still run. i've got a Q2 on my '03 and i really doubt it'll come close to 93db. (don't let any body tell you the Q2 will turn your wr into a freak'n rocketship either) don't sell the stock can short. try all the free mods with the stocker before you shell out any more money. 93db is pretty darn quiet, stock may be your best bet one way or another.

Right now i'm running the Dr D round muffler with Dr D header. It is too loud with out the cone(103 Db) and with it (claimed 96, but it's higher). I need something under 96 that'll work with my header that has a SA. I went with the Q2. I have one on the way now. DR D claims the header will accompany any muffler that fits the stock header. The Q2 fits stock. My bike didn't have the stock header/muffler on it. I don't plan to gain any power from it, I just need something that WILL be noise legal and won't piss off the neighbors. Check my garage for the mods done to the motor.

[mtrablue]

the Q2 should hit the 96db but the 93db the guy was worried about, i don't think so. i'm not going to embarrass my self pretending i understand the decibel thing but i do know that it's not just three points on a scale from zero to ???. a three decibel point drop is a big reduction in noise.

[OneToGo]

For info Guys:

the Q2 should hit the 96db but the 93db the guy was worried about, i don't think so. i'm not going to embarrass my self pretending i understand the decibel thing but i do know that it's not just three points on a scale from zero to ???. a three decibel point drop is a big reduction in noise.

These figs. are what I know from my research. The "Quiet" Pipe manufacturers seem to slightly understate the noise "emission" from their quiet pipes - for obvious reasons.

The Q2/E2 or wahtever, are all advertised in the 93 Db region - realistically, after the packing gets a thrashing, they probably test higher, I wouldn't doubt close to 96db as quoted above.

It would be convenient, for all those to whom noise emissions are important, if someone could publish a sound test. I did not see the recent test quoted in this thread, can anyone post the results?

FYI, as a rough guide, an increase in noise from 93 to 96 Db is like having TWO bikes emitting 93 Db, an increase in 3Db is around double!

Colin

[Beef]

FYI, every increase in sound of 3dB is EXACTLY double. The dB scale is "logrithmic." 6 dB gain is 4 times louder, and so on. ??

[mtrablue]

i thought it was something like that. i'm told the yamaha engine design (five valve head) is supposed to create a problem of it's own when trying to quiet it down. when the mags do sound tests using another brand, it doesn't give us "real" numbers.

[hankdog]

The March issue of Dirt Bike shows 91 dB@4500 rpm for the stock pipe with the pea shooter removed, and the Q2 at 98.5 dB@4500 rpm. As someone pointed out the dB scale is non-linear, 7.5 dB is a huge difference in sound level. I know it ain't cool, but I like the stealth mode of my stock '05 pipe with the pea shooter pulled out.

They did say however, that the WR is one of the few bikes on the market where changing the pipe actually does give you a horsepower boost, they show a 2hp gain with the Q2. On the Honda CRF450X, the HP actually went down from stock with the Q2, but the sound level remained the same - go figure? ?

[MKP]

Have a question:

Can I ride without the "tail pipe" and without the spark arrester, ..... just the end cap ??? ??

No sound restrictions here.

Thanks

Marco

[MKP]

Need help & have a question:

Can I ride without the "tail pipe" and without the spark arrester, ..... just the end cap ??? ??

No sound restrictions here.

Thanks

Marco

[MKP]

Sorry...internet traffic congestion. ??