What do those $20 and $30 compact ebay chambers do?

[forties]

Do they at least make a little power? Or just make lots of noise. The fact that they are compact and cheap is the appeal here right..

I do realize something which makes good power is going to take fab hours or cost real money, just curious what exactly the cheap ones do? For their size and price a small power gain would have me considering one.. But is there even a small one?

I did search for "chamber" and "chambers" but didn't see much come up.

 

[forties]

No matter what I go with I will fit a good silencer to it. I do actually care to not annoy my neighborhood.. but yeah so do that compact chambers do anything at all above and beyond the non chambered stock exhaust?

 

[Venice Motor Bikes]

They don't work!
The best way to get a properly working expansion chamber is to use one from a 80cc motorcycle & weld on a flange to bolt it to your engine.

 

[Bikeguy Joe]

Yes, with the addition of a boost bottle they will give an increase of approximately 20% in imaginary horsepower.

 

[wheelbender6]

You have any documentation on that imaginary horsepower increase?

 

[Bikeguy Joe]

Well, isn't it a well proven fact?

 

[forties]

Well that is a shame. You would think they would at least add 10% or something. I'll just stick with the stock non chamber pipe then. At least its quiet.

 

[forties]

WC80 MZ65 Style Exhaust Pipe Expansion Chamber | website

Brand new high performance pipe. Unlike the CDH/Zeda version, this pipe is much larger and with larger diameter ports. It may have some blemishes from the chroming process or handling. Welds are not perfect due to price constraints but no leaks and made of good quality thick guage...

www.californiamotorbikes.com

What about this one, this do anything? Its not $20 but also not $200. Maybe I'll stop being lazy and get a mx pipe and start cutting and welding it to work.

 

[forties]

Just read on another internets thread that the 20 and 30 buck ones have chambers just for show. There is actually an internal pipe through 90% of the chamber which defeats any expansion effect.

I found a smashed up 50cc ktm pipe I may try to do something with. Something something water freezer, something something cut weld.

 

[SloRyd]

I’m running this set up, although I can’t compare it to the stock silencer since I just built the bike last Friday night and cut and slipped the stock silencer into the end to quiet it down. Paid $59 on Amazon and did it more for looks....the placebo effect has gotta be worth 1 mph, .

 

[forties]

Yeah I'm not down with shelling out 75 bucks for placebo effect.

The $20 placebo pipe.... my OCD azz would have to chop it in half and make sure the internal pipe didn't go thru the chamber. Which is a pain so I won't buy it.

 

[SloRyd]

I was assured that the MZ65 doubled the power output on a 66cc China motor on another forum....”Dyno proven” in fact. Only dyno video on that pipe I could find was on a new motor and it netted another 1hp. Fortunately this one is a true expansion chamber and not a belly wrapped around a through pipe...what more it added, I have no idea. But I’d imagine it had to be an improvement over the stock silencer....other reviewers with broken in motors claimed it really helped. I was told the head pipe wasn’t stepped like an MZ65 so it wasn’t doing anything. Whatever, lol. But, again...I just did it more for looks than anything

 

[forties]

Yeah I'm crystal clear on which pipe has the thru tube. The 20$ one. Not the $75 one. Thats cool you like what you got, I can respect that. $75 for me is high enough that it would have to go towards a trashed 65cc or 50cc bike search fund. Get a pipe. And everything else.

 

[FOG]

I’m running this set up, although I can’t compare it to the stock silencer since I just built the bike last Friday night and cut and slipped the stock silencer into the end to quiet it down. Paid $59 on Amazon and did it more for looks....the placebo effect has gotta be worth 1 mph, .

I couldn't hang with a straight pipe on a 2 stroke either, so I went with a pocket bike motor. The pipe on it is just about cosmetic, but the pocket bike guys tell me that adding a 4" belly yields a useful mid range boost so I did that. And corrected the header pipe. It was sticking in there about halfway up the 1st cone.

The other dumb thing is the "dual exhaust"! That' just about stupid but it looks cool so I'm gonna use it.

 

[SloRyd]

Aww man, that’s cool as ****...I’m digging the dual exhaust. Reminds me of a Ducati setup

 

[Venice Motor Bikes]

Here's a link to my last race bike... https://motorbicycling.com/threads/newest-venice-race-bike.61100/
It had a FMF ~ CR80 pipe that I cut & reworked to fit the bike.

I later added about 3" to the header to bring the power band down to lower RPMs for the track.

This will give you a idea of what you need if you want to get serious about making more power with a pipe... (anything else is a waste of money.)

Honestly... with all those other cheap pipes, you'd get the exact same power gain if you just used a simple 'straight pipe' instead.