Beating a Quiet horse

I've just spent the better part of 2 days searching old threads and new ones in seach of "the answer"

So here's the Question.. :)

IS there a 4 stroke exhaust on the market that doesnt kill my low end, (im not terribly concerned with top end as I ride mostly woods in CO) and WILL meet the 96dbl mark?

Who makes it?

Most of the informative posts that dont slide offtopic and turn into a rant/flame are from years ago when pipes like the CRD were R&D.

I'm willing to put down a shiny nickle for it because my PC t-4 is a freaking megaphone and I'm pissing off the neighbors. :D (plus i dont really like its power curve.)

The FMF Q seems good, but like every other pipe someone claims they tested at 99-100 which is much higher than the 96 i need for neighbor friendly street legal-ness.

CRD doesnt seem to make one for a 99 YZ400.

I cant get a straight answer, or i misunderstood the post, but WB e-series tunable plates seem to adjust powercurve and such, NOT dbl.....true?

Im so confused my brain hurts.

Thanks for any help

Dan sells inserts for about 35 bucks which will bring your Db's down below 96. And they claim better performance than the stock pipe on some of the WR's etc..

check it out....


I have a FMF Q for my YZ450. It is definately quieter than the stock muffler but louder than the WR stock muffler. Power is slightly mellower of bottom than the stock exhaust and about the same mid through top. Again this is compared to the stock YZ450 exhaust. It is considerably quieter than every other "performance" pipe I have heard. I have had guys ride my bike coming off bikes with loud pipes and they say they don't like it not because of the power but because they can't hear the bike and know when to shift :)

Thanks for the link but this is pretty good example of the vague/wandering thread i mentioned above. Of the 3 pipes mentioned (Q Eseries and PMB) only 'rail45' with the PMB claims to meet the 96dbl req. and from the other posts including another post in tis same thread by 'ovrrdrive' he claims his PMB wont get below triple digits on a sound check. This is much the same with the FMF Q. I'm also a bit concerned with the mounting situation on the Q.

I will admit that the data is probably a bit skewed because most of these bikes are 426/450's and the posts are from a few years ago meaning theres been alot of time to update technology, which is really the heart of my question...Who makes the quietest fix this year?

Does the PMB S/A with Quiet insert hit 96dbl consistently and how does it compare to the Dr D? i like the allen screws better than the PMB rivets

Is the FMF mounting still lame? I think the FMF makes a good quiet pipe esp. with the powerbomb header, but it has to stay on. How's yours holding up 'Mikedabike'??

Unfortunately i dont have the resources to make a vortip or really anything else so i pretty much gotta stick to Pre-fab aftermarket.

Sorry to pose so many qustions but i got one shot to get it right.


. This is much the same with the FMF Q. I'm also a bit concerned with the mounting situation on the Q.


Okay, I just last night put on a Q on my YZF. I am riding on saturday, I'll let you know how it goes. I bought it out the door at performance cycle in denver for 279$ bones.

In the neighborhood it seems much quieter poking around. The bike has so much power I haven't noticed any loss. It still sounds like a beefy 4 stroke it just doesnt have that metallic screaming sound like the stock pipe.

The mounting setup seems fine, why does everyone gripe about that? In fact you don't need to use the stock poofy gasket at the header juncture.

I just finally got my new FMF Q2 and it is definately a lot more quiet now. Unfortunately I have my bike all torn down now and can't give a ride report yet. According to FMF it's supposed to make more power than the Q, but I don't have a Q to compare to and I'm coming from a WB R4 so anything is going to be quieter and have a little less power than my old pipe. It still has the cheesy mounting set-up, I don't know why FMF refuses to listen to feedback on that. It seem like it should hold though, if not, I'll be fabbing up my own.

Seems like the older quiet pipes are quickly becoming outdated technology so I don't think I'd spend the money on one of them. They're cheaper for a reason, they gotta get rid of them before they discontinue them. The older pipes were all engineered to get to 96 db, the newer ones like the WB E2 or the FMF Q2 are being engineered to get under 96 db to give the buyer a little time between repackings. Add to that, you're trying to quiet down a Yamaha. Call any one of the pipe companies and they'll all tell you the same thing, the Yamahas are the hardest to quiet down. Most, if not all, of the older quiet pipes I'm sure are under or right at 96 db, and some just over, when they're brand new, but after a couple rides they can't pass sound anymore. Unless you plan on repacking after every other ride, I don't see keeping a Yamaha within 96 db with any of the older pipes. Ok, that's a bit mello dramatic, but not by much.

BTW, any pipe that's made for a 426 will fit on your 400.

Wow, myoung you read my mind, while surfing the 'net i found FMF's "NEW" Q2, dropped in to see if anyone had any feedback on it LOL!

i gotta say right now thats prolly the front runner for my choice unless you tell me its a POS.

Good to know about the 426 retro fit as well... anyone have any expierence fitting a 450 pipe into a 400? CRD makes a nice pipe, but as per the phone rep (who was incredulous that my YZ is plated) the only model they make is for the 450...

wondering about the fit and neccessary mods. it seems a good buy for the buck


I don't see the 450 pipe working on your 400. I did the 450 'change over' to my 426 and I had to make a bracket to get my exhaust to bolt up to the 450 subframe. There's about an inch difference in where the rear mount is located. There may also be a difference in where the header and the mid pipe come together between the 450 and the 400/426, but I don't know for sure.

I don't forsee the Q2 being a POS, if anything it should perform just as well as the WB E2 or possibly even better. My buddy has the E2 on his WR450 and it performed pretty damn good when I rode it. Only other mod he has is a disconnected blue wire to give his bike the YZ ignition mapping, he still has the lazy WR cam timing and I was still impressed when I rode it.

Personnally, I don't think you could go wrong with either the E2 or the Q2. The Q2 is a little harder to get your paws on right now because they just came out, I had to wait about five weeks to get mine from They gave me a smoking price because I bought a bunch of stuff all at once so I stuck it out and waited. They don't list the Q2 in their catalog yet, but they can get it and it's cheaper than the E2. Only cool thing the E2 has over the Q2 is the removable quiet core for when you want to hit tracks, the Q2 is permanently a quiet pipe.

There may be some others coming down the pike soon with better quiet pipes as well. I think companies like Big Gun, Yoshimura, Dr D, and any other big names will have to adress this need as well to stay on top of the market. It really is the way everything is going. It wont be long before even the pro's will have to quiet it down to race on the tracks. I know they already have sound level requirements, but I don't think they're enforced. With the slow overtaking of the racing series by the four strokes, the increase in the ammount of noise created by a bunch of loud race pipes will eventually wear out its welcome.

Thanks for all the input guys, i got a pretty good deal on a Q2 so i went with that. We'll see how it works next week!


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