Aftermarket 4-Stroke Exhausts: Just a Bling Part?

I’ve always noticed a difference in how it moves the power around with a full system. Always run FMF and a Mega Bomb with a 4.1 really wakes the RMZ up off the bottom. On my 17 I also did notice a difference with just the 4.1 slip on. Bought it more for the spark arrestor than anything else, but I definitely noticed a difference from stock. Not as big as I did with a full system, but definitely noticed. 

Plus the OEM system is a freakin boat anchor!

One of the most interesting posts in a long time.  Yes, where are the performance charts?  This is easy to obtain, compare.  Where are the published weights?   If it shaves off 400 grams, is the average rider going to notice in any way?   Maybe only their wallet. 

Also, why does a little single cylinder exhaust system cost $400 more than a full Borla twin Cat system for my 6.2 Camaro?

FMF? The company that sells t shirts makes exhausts?

It’s interesting that Honda went from dual exhaust, to single exhaust, back to dual exhaust, and now here we are in 2025 with single exhaust again.

It’s been 6 or so years since dual exhaust.

Will Honda return to it? Honestly I think it looked badass

Buy whatever makes you happy as long as you can afford it.

Absolutely waste of money on my 22 350SX-F. I got good results from the vented side cover, a cageless air filter and adding one tooth to the rear sprocket. 

"Better" means nothing. Totally depends on what kind of engine personality you're looking for, if you care about noise or not...

i buy them strictly for looks

Maybe on a 125cc so you can get a pipe for more top end or a broader powerband. 

I have a 2000 cr 250 and have a bills, fmf, and a pro circuit , they all change power delivery, but I wish I had the sock pipe, if anything for the durability 

I can only give you my experience, but my 2024 KX450 came with an exhaust designed to meet the new Euro standards.  Putting a PC exhaust on made it a completely different animal.  Am I any faster because my bike makes more power?  That’s certainly debatable.

such a waste of money for a 450. Just funny to me when i see all these vet guys get brand new pipes right away and they are not even at half throttle as it is  

If you're walking into a new exhaust thinking you'll shave seconds off your lap, you're delusional. There's a reason you see guys qualifying for nationals with stock exhausts and kit suspension. If you're looking for more speed on the track, your money could be better spent than an exhaust. I share the sentiment that in most cases (>85%), a new system simply shifts the power around to deliver differently than stock. Truly down to the user's preference of feel. 

That being said, when I feel that I can afford anything with a carbon cap or an Akro, I'm buying that shit cause it looks bitchin. 

If you are even remotely fast enough to where a minor power improvement can make a difference....then you need to spend that money on suspension setup.

End of story.

If it makes you happy, it can't be that bad....

I learned this lesson on 500s back in the day! 🤣

You wanted an entirely different set-up for Hollister v. Saddleback. 

The older...and slower I get...the more i value comfort , confidence and control. The best money ive spent is on suspension and not so much on exhaust.  The newer 450s are plenty fast for my old ass🤣.  Thank you GB🙏

Better on the dyno.  If you watched the video you would know what I meant.  The OEM system made more HP and torque pretty much throughout the RPM range.

I’ll add, as was mentioned above, most OEM systems look like shit and weigh a ton.  I would put one on just because they look better, but mostly for the weight savings.

Ragebait

Depends mostly on the bike, 2006-2009 YZ450f needed a pipe like a fish needs water.

I've tried the stock, Yosh, and PC full systems on my '25 RM-Z 450. Yosh looks sick but its heavy, PC is a few pounds lighter than stock. I feel like the stock pipe pulled harder down low than both. 

Took this after washing the bike and thought of this thread..... would never argue that I'm capable of using any of the power or feeling any difference in weight but damn it looks good..... 

sounds better, looks better.....90% of riders probably wont notice the performance difference.  Last mod you should do for performance on modern bikes, but if you got the money they do sound nice.

Case by case basis. Some bikes really benefit from an exhaust while others have no noticeable change. Pretty much any upgrade is like that. 

If they made any real difference, manufacturers WOULD publish clear and confirmed dyno charts, they don't, as they know... it's all bullshit.  It's a cosmetic upgrade in pretty much all cases.   If they're serious, they publish test results, every single time.   They seem to suggest every pipe is 'tested', and 'developed'.  It's worthless if you don't show performance gain results, which obviously would be part of any test/development for each model they offer.  

More noise, or different sound, can play games in your head, but, it's no faster.  

Sometimes, you need a new pipe, cause you need a new pipe, the only time you should change:

Personally I bought an fmf slip on knowing full well it wasn’t going to change the power characteristics on the bike. I just wanted an FC350 factory edition and they didn’t make one. They did however make a heritage edition with a white frame so I could build my own. I wasn’t going to do the can but found one for a good price on eBay, and figured why not? Some people buy stupid shit for their cars or truck, some people buy jewelry to bedazzle themselves, we buy dumb shit for our bikes. 

100% right on.   We're all suckers for Bedazzlement!  Like average Joe buying hubs.... or triple clamps.  Your bike already has them, that are so far over engineered from OEM, it's not funny! 

Placebo effect is a real thing. Sound faster, go faster?