FMF Q wanted

Anyone have a Q and FMF powerbomb header they want to sell for a 03 YZ450?

Has anyone made a homemade screen spark arrestor for the stock muffler?

I also am interested in picking up a fmf q or q2 for my 00 426.

Has anyone heard anything good or bad about the White Brothers e2 quiet silencer?

Has anyone heard anything good or bad about the White Brothers e2 quiet silencer?

The new Q2 and Ti Q's are the best 96db mufflers out there right now, it's a better design than the E2's.

If weight is a big deal for you, the Titanium Q is less than 4.5 lbs including the midpipe and clamp. Most stock silencers are around 7 lbs and some aftermarket and WR pipes are more like 8 or 10 lbs. 3 or 4 lbs off the back of the bike is a big deal for me, the average cow trailer is never going to tell the difference though so it depends on your preferences. Unfortunately I don't think they're making the Ti Q for the 426's yet so you might not have a choice. The Q2 is the same design as the Ti Q, just in aluminum. Excellent low end torque and not a huge loss of top end like most 96db pipes.

MotoGoalie... The Pro Moto Billet end cap is the easiest way to make a stock pipe spark arrester legal. I don't like them though because they're too much money, too heavy and there's too big of a power difference with the screen in vs. without. That also won't be a 96db pipe. Putting in the "quiet insert" gets it down to 96db, but also takes away a ton of power. You might as well stick a cork in the end of the pipe.

You can build your own spark arrester into the stock pipes core, but it takes some know-how and you'll also have to convince any rangers that it really has a spark arrester. Save yourself a lot of hassle and just find a Q. I wouldn't recommend the older Q's though, there's a big difference between the old design and the new ones.


Yo bark';

thanks for the info. It makes sense to me then to keep the stocker for the track and switch out for the Q for the trail.

I was suprised at how light the stock muffler for the 03 is. I can't see paying 300 plus for the Q2 or tiQ. Even when you buy the White E2 you still have to purchase the quiet core which jacks the price way over 300. The price of these things is totally wack, so I'm gonna E-bay it I guess. I just need it to quiet the bike and be a S/A. Performance on this bike, trailriding and what not, is not paramount.

If I need performance I'll just put the stock muffler in place. Adding 2 more horses on this monster would just get me thrown onto my ass faster. :naughty:

One big thing I've been considering is the headers durability. I understand that the Ti stocker is quite fragile to rocks and whatnot so I guess a steel header would be an upgrade for durability offroad too.

What is the "big" difference in the older Q compared to the new one?

I installed a PB and Q on my 2000 426 and was kinda dissapointed, but I was coming from a Ti DSP open system. I might consider selling my Q or trading for a factory 4 system, but I am keeping the PB.

What is the "big" difference in the older Q compared to the new one?

Basically they opened up the restrictions on the newer Q’s, the older ones were more plugged up.

The Q’s use a turbine core (Krizman) spark arrestor instead of a screen, for the most part it works better for 4 strokes than a screen design. There’s no chance of plugging up and they won’t break apart like screens tend to do in 4 strokes. I think the biggest reason most aftermarket pipes have screens is they’re cheaper and easier to make.

FMF puts a funnel shaped piece of perforated core after the turbine core to restrict the flow a little and keep the exhaust in the core a little longer. It also helps divert the exhaust outward into the end chamber. In the older ones that piece pretty much covered the opening of the turbine core, that’s why they didn’t make very good power but were plenty quiet. If you look in the end of a Q you can see what I’m talking about.

The newer design has a much smaller piece after the turbine core, just enough to get the exhaust pulse to bounce around into the end cap a little. I’m betting they spent a lot of time getting the dimensions of the end cap and end chamber just right. It seems like at around 4k rpm (about the test rpm) the exhaust note doesn’t have any “pop” to it, like the sound waves are being cancelled out as they go into and out of the end cap chamber. The beauty of what they accomplished is it still sounds good at full throttle. My theory is when the exhaust flow and pressure in the end cap chamber is high (full throttle) the exhaust flow can’t bounce around in there, it has no place to go but out.

If you look through the core of a new Q, you’ll see there’s not much to restrict flow, I knew it would make decent power just by looking at it. Remember, I’m comparing it to other QUIET pipes, obviously it has more restriction than a straight-thru silencer, but we can’t use those much anymore here in CA, except for some tracks. Even the tracks are requiring stock pipes or quieter.

My Ti Q tested a little on the loud side when I had the kiddies at Hollister test it. It tested at 97db, but they weren’t at 45 degrees to the centerline of the bike. It seems as though they’re trying to bend the test procedures a little down there, trying to put the sound meter straight behind the pipe. 97 is still passing so it didn’t matter to me, it shows that FMF leaned a little more towards the loud side with the newer pipes. The old Q’s seemed to be testing well under 96db.

If anyone has the older design Q, and they want to get some more power, it can be done fairly easily. I’m not advocating any muffler modifications here, it’s not my fault if you ruin your muffler or get thrown in jail for modifying a USFS spark arrestor. (This mod won’t affect the spark arrestor’s operation, it will still work perfectly.)

If you look in the end of the Q, you’ll see the perforated piece I’m talking about. If you take the muffler apart you’ll be able to cut about 1/8 or ¼ of an inch from around the inside diameter of the opening. A Dremel tool would be perfect for the job. You should then be able to see the fins of the turbine core, the piece blocks most of the fins on the old ones. If you can find a new and old design Q to look in, you’ll see how much can be cut out of the old ones to make it work like the newer ones. If you make the perforated piece look like the new design, I’m sure it will make a noticeable power difference. It won’t be as good as the new ones though because the end cap design is completely different.

Remember, I never told anyone to take your mufflers apart and hog them out. I would make sure your pipe passes a sound test before and after. If mine tests again at 97db, I certainly wouldn’t be opening it up to make it louder. If you have an older design that’s testing at 93db, and you know how to take things apart and modify them without wrecking them, AND you can use the extra power, go for it. (I didn’t say that.)

Before a bunch of people jump on me for anything I’ve said here, these are MY OPINIONS AND IDEAS. You can take them or leave them. I don’t work for FMF and I’m only guessing on what they were thinking on these pipe designs. I’m not an exhaust expert, but I have spent a buttload of hours building (modifying) my own exhausts so I do know a little.


Thanks for the info. I'll probably try to pick up a used Q and just swap back and forth between my loud a@@ white bros and the Q depending on situation.

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