SBP Muffler vs Honda CR80 Expansion Chambers

GoldenMotor.com

Keef B

New Member
Dec 30, 2015
19
0
0
northridge
Fellas,

First and foremost this site is like a godsend for me.. I can sit and talk bikes all day and pass the time at work. hahahahahahaaaa But wanted to get your thoughts on the SBP expansion chamber vs the Honda CR80 expansion chamber. Now from my understanding bigger is better, so i was thinking the Honda CR80 would be the best bet. But after doing some research I i seen this SBP expansion chamber and according the to the site its specifically tuned for the china girl engines.. So my fellow bike brothers please shower me with your knowledge.. it would be greatly appreciated.
 

xseler

Well-Known Member
Apr 14, 2013
2,886
151
63
OKC, OK

Bikeguy Joe

Godfather of Motorized Bicycles
Jan 8, 2008
11,837
252
63
up north now
Unless you can get the Honda pipe for next to nothing to experiment with, I'd go with the SBP pipe.
People have used moped pipes, or chambers made for mopeds too.
 

bairdco

a guy who makes cool bikes
Aug 18, 2009
6,537
264
63
living the dream in southern california
The SBP pipes, in my experience, work great on mostly stock engines, as a bolt on upgrade. Once you start adding big carbs, performance heads, enlarging ports and going for the max hp possible, you need a pipe twice the size.

I modded a ktm pipe that's 6" at it's fattest point, and it worked great.

There isn't a "one size fits all" pipe design out there. To truly get the most out of your particular engine, and to get the power band you want, you'll need to do a lot of experimenting.
 
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Keef B

New Member
Dec 30, 2015
19
0
0
northridge
Thanks @Bikeguy Joe and @Bairdco, @ bairdco your in socal like me. Where are you located?? I have a MC junkyard I'm going to visit soon and see if they have the CR80 pipe I need if not good ole e-bay should have one for sure just don't want to wait for it to be shipped..
 

Bobo08

New Member
Jul 26, 2015
3
0
0
Falmouth MA
I just installed the sbp x pipe on my 66 cc and i was amazed with the performance increase . Truly amazing . I have no other mods other the. NGK iridium, 6 cc head and a quick intake /exhaust matching . I weigh 220 on an old trek with 41 tooth . This pipe adds so much low end all I need is a 36thooth and I wouldn't wined up this engine so high to reach a decent speed. That all bieng said this pipe is specifically ment for those who don't like or know how to fabricate. It's easy to tune and easy to tell if you have it tuned . I am however curious what the dirt /pocket bike pipe would do . $74 this is the cheapest most notable bolt on mod and think you don't have a real China girl unless you put a decent x chamber on it . Love this thing.
 
Fellas,

First and foremost this site is like a godsend for me.. I can sit and talk bikes all day and pass the time at work. hahahahahahaaaa But wanted to get your thoughts on the SBP expansion chamber vs the Honda CR80 expansion chamber. Now from my understanding bigger is better, so i was thinking the Honda CR80 would be the best bet. But after doing some research I i seen this SBP expansion chamber and according the to the site its specifically tuned for the china girl engines.. So my fellow bike brothers please shower me with your knowledge.. it would be greatly appreciated.
I just got a CR 80 exhaust and it was the difference between 40mph and 55mph on an uphill incline .It seemed to be built to suit on my GT80 from gasworks motors
 

KCvale

Well-Known Member
Feb 28, 2010
3,966
57
48
Phoenix,AZ
For the SBP X-pipe the sections are tuned for a 48cc, for a 66cc cut the short copper straight piece in half.

They work great and have a lot of flexibility to mount, but you really have understand how they as bigger is not always better, it all about timing.

Follow the green gas in this animation of how they work.
All an X pipe does is shove the wasted unburnt fuel back into the cylinder just before it fires...



...but man it's a big boost when tuned right ;-}