Aftermarket 4-Stroke Exhausts: Just a Bling Part?

IMO largest waste of money in the sport. 

I also ride a 350.  Use that money for fuel, track days, and tires.

I did the akro on my 23scf450 solely because I heard it was quieter and stock was obnoxiously loud.

Wearing ear plugs now as well when I ride my stock bike

Can't answer from personal experience, but I remember watching this video a couple years ago and being mildly surprised...  The OEM pipe was better than the FMF.

https://youtu.be/DIv-w0o7EzA?si=wemaR9ET8rEQ_Z9b

i did the same thing! stock was crazy loud i thought. plus i just always wanted an akro lol

Biggest waste of money in the sport...spend the money on riding schools, fuel, and tires and almost every rider out there will go faster for the money spent.  (I'd say the same thing about almost every aftermarket mod, though...even suspension revalves...spring the stock suspension for the weight, and spend the money you'd of spent on the revalve on riding schools, fuel and tires, and you'll go faster for the money spent.)

Depending on the OEM muffler...aftermarket might be a bit less weight? 

Running stock exhaust on my 22 FC350 and no plans on replacing unless something happens to the stocker. 

Most of the new 4 strokes' OE mufflers are absolutely hideous, so there's that.....

The Akrapovic on my 450 factory edition doesn't seem overly loud and the power is very smooth (I don't know if it's less smooth with an OEM silencer - I can only say what it's like now).  I've had FMF silencers in the past (KTM 250 and 350) and I think they were louder than stock. Any improvement in performance that I perceived was most likely just extra noise. But that blue titanium with a carbon end cap looks really nice. 

Akro on sxf450 is smoother and quieter for sure

Unless you bend/smash your pipe beyond repair, waste of money. Of course people will get the pipe and new graphics but run crappy tires…

Waste of money. Why would OEM’s leave power on the table. They have more resources than the aftermarket companies to ensure they’re putting the best performing pipes on their bikes.  This is just a carryover from the two-stroke days when there was available power to be had. Everybody automatically bought a pipe for the two strokes and it became ingrained in the culture and carried over into the four stroke era. Did anybody expect the after market companies to just shut their doors….

For a while my Husky 350s were coming with a perforated cone in the muffler so an FMF did make a big difference. The weight is obvious too if you hold both mufflers at the same time. You can run FMF's 350 header or 250 header on the 23-25 350 as well depending if you want the power down low or in the top end, so kinda more changing where the power is more-so than adding HP. Like anything else, it just depends. These days though if a full system is $1,400 you can get a Vortex ECU from Twisted or XPR that adds HP and gives you 10 different options of where the delivery is for roughly the same money so if you're actually looking for performance that's far and away the better bang for your buck.

Go for the stainless counterpart instead. You’ll get the performance gains without the premium cost of a full titanium system (exhaust pricing has gotten out of control, especially for current year bikes) and an overall better quality of life. Slip-ons are a viable option but some brands offer the full system for an incremental price bump. I’ve found the stainless systems to be lighter than stock in my experience but I’m sure it will vary depending on the OEM exhaust and various aftermarket brands, so don’t quote me on that.

As for ti-exhausts, the carbon end caps are expensive and fragile; have broken multiple caps in minor tip overs and found they eventually wear out from vibration. I’ve noticed the canisters warp due to the heat and go through packing relatively quick. Another pet peeve is the muffler stickers can burn after only 1 ride, even with fresh packing. Lastly, we have a lot of rocks in our soil at our local tracks, so I’m leaning on the side of caution and avoiding going with ti-headers.

Even back then my argument was:
"So the Japanese have all the resources and as soon as the new model is stateside, FMF and Pro Circuit say "hold my beer for 2 weeks while we do a better job than Y, H, K, S did over the last year(s) of development....

Now, make significant cylinder, head, case, carb, ignition changes?  Sure, a custom tuned cone pipe that is specific to those changes, I can get on board with that.  A new FMF fatty on a stock 125...?  Not so much.  

Like others have mentioned, replacing a wadded up exhaust is a different story... 

Just like ol' Mathis was recently reminded, you have to hold it WIDE OPEN before you worry about anything else....

Doesn't really apply now, but I had a 2008 250SXF that was an absolute dog. I couldn't clear jumps that I could do with my eyes closed on my 05 CRF250. I put a full system FMF on and it was a night and day difference. Still not as good as my CRF, but I could at least get over some things. 

That being said, I put a full FMF on my 21 450SMR and noticed that it moved the power around, mellowed out the low end and seemed to extend the top end, which is exactly what I wanted for supermoto, but I wouldn't say it provided more power. 

I also currently ride a 24 350SXF and have read that for that particular bike (I think newer 350's in general) the OEM setup is about as good as you'll get.

2 stroke or 4, the stock exhaust works fine. Get a gym membership and tires.

In SX we were using the Dubach slip on and let me tell you, the way Doug and Jehan developed that unit was unbelievable for low end. The inside of the can had some really high tech staged cones that got larger and smaller to produce low end. It worked. 

Also when I say low end I mean usable torque, not a specific rpm range. 

Couple random phone pics from NJ and Nash

I could feel a difference when going from my stock yz to a full pc system on my 2024 yz450, however I can feel a much bigger difference by changing my maps around for free in the app. When I was 18-30 and couldn’t afford it, only the bikes that’s needed pipes got them. Now that I’m 40 and can afford it, every bike I own has pipes and all future bikes will too, they look cool and my bikes are my favorite things in my life.

For 2 strokes a pipe can make a huge difference. You want your YZ 250 to be a torquey woods bike - a flywheel weight and a gnarly and you’ve got a very different bike. Not more power - that’s not the point. Better power for what you’re doing. 

I put an fmf slip on muffler with ca4bon end cap on my 350sfx….I rarely crash…. Sure as shit, I crashed first time out with the new slip on, of course I fall on the exhaust side right👍…. Did feel like I gained more overrev, if thats even possible on these 350”s, they already rev to the moon…..I”m old and ran stock shit most of my life due to $ always being tight…. Not much time left on my Mx life……I”m going to buy anything &  everything I ever wanted…. I should order some Ti shit right now💪

Consumer has to pay stupid prices so the company can afford to "give" the teams and their industry friends free pipes.

I agree with one of the posts, if we're paying the price, post up the dyno.  

I can tell you with certainty that the FMF pipe on my 2016 CRF450R weighed less than stock… due to having one less can. lol

Yosh for current gen Honda is something like two pounds heavier. 

2008-2009 YZF 450 (US version):

-I cant breathe!

https://motocrossactionmag.com/forgotten-motocross-tech-inside-secrets-of-the-ice-cream-cone-muffler/

For sure my FMF system woke the bike up! 
 

Also: the Dubach full system for the (2004) CRF250 was insane, like a big bore kit!! Torque!

Waste? Maybe so. Do I love getting one?  Fuck yeah 😃  

Some bikes may benefit, some not.  Do your homework and decide for yourself.  

Some people don't care about more tires or gas money, they just love their bike and want it to look a certain way.. nothing wrong with that. 

100% on the crappy or worn tires.  

Idk I’ve always felt a difference in power from throwing a system on my bikes.

2020 KX250 pinned 4th gear would just barely put me over this big double, threw an FMF header and slip on on it and pinned 4th gear had me landing right where I wanted.

25 KX250 I balled out and got a PC full Ti system. Carbon cap looks bitchin and so does the titanium. If you have the money and it makes you happy, buy the damn exhaust system.

We don’t get as much time on our dirtbikes as we wish, so why not make your bike yours? 

Even if they made an extra 10hp which obviously they don’t, they wouldn’t make 99% of riders any faster, unless you ride with the throttle wide open and find yourself saying, I wish this had more power, which none of us do..

It’s your brain that determines how fast you ride, not your bike 

I remember when the 2006 CRF250R came out with the dual exhaust, I got one brand new and bent one of the pipes out sideways after someone hit me. Dirt Rider was doing a pipe shootout with all the exhaust companies making single and dual versions of their pipes, and gave away all the test pipes to people that would send in pics of their messed up stock pipes. They sent me a single-side Dr.D stainless exhaust and that thing was loud, definitely gained a few HP according to the butt dyno. I never win shit, so that was pretty cool.