will adding a tuned pipe increase mile per gallon?

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mr42ndstblvd

Member
Nov 10, 2013
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6
oklahoma
i want to put a tuned exspansion chamber on my bike mainly because they look awesome and sound cool and give more power but ive also been told that it will increase fuel economy at the same time?? is this true??
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
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Central Area of Texas
i want to put a tuned exspansion chamber on my bike mainly because they look awesome and sound cool and give more power but ive also been told that it will increase fuel economy at the same time?? is this true??
I dont know that it will, fuel economy os good on them no matter what you do to them basically, an expansion pipe set up right will add torque and they do sound good, but I dont know about the better fuel economy, mine do pretty good and I ride fast almost all the time, upper 30's to low 40's mph and I figure mine get about 70-80 mpg

Map
 

Will122391

New Member
May 31, 2013
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Texas
I have the SBP expansion chamber, which is widely regarded as a great pipe. But I didn't notice any extra power when I threw it on. With barely 3hp to start with, I'm sure a tiny bit of power was added, but nothing I could easily notice.

The pipe adds a lot of character. My engine pops and bangs when its warming up and sounds fantastic. I could never go back to the weedwacker-sounding stock pipe. So yea it's mainly to sound cool, but there's some power added.
 

Theon

New Member
Jan 20, 2014
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FNQ Australia
If your pipe does add more power, you will use it, and your economy will suffer.
Most pipes on the market will not give you much extra power, some might give a little better low down.
 

mapbike

Well-Known Member
Mar 14, 2010
5,502
109
63
Central Area of Texas
If your pipe does add more power, you will use it, and your economy will suffer.
Most pipes on the market will not give you much extra power, some might give a little better low down.
Ditto..... well put and very true.

I will add that a sickbikeparts expansion pipe will add some hill climbing torque and a little increase in top speed IF.... carb is well tuned....... IF.....gearing is right......IF...... switching from a very restrictive catalytic type stock exhaust, there are a couple other factor like weight of rider, fuel/oil mix and the overall balance of the engine plays a big part of power and speed potential with the china girl engines.

Map
 

maniac57

Old, Fat, and still faster than you
Oct 8, 2011
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memphis Tn
More power = more fuel = less mileage.
But you will never notice unless you are a fanatic about keeping track.
 

Toothy

New Member
Mar 25, 2014
181
1
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San Diego
I have the SBP expansion chamber, which is widely regarded as a great pipe. But I didn't notice any extra power when I threw it on. With barely 3hp to start with, I'm sure a tiny bit of power was added, but nothing I could easily notice.

The pipe adds a lot of character. My engine pops and bangs when its warming up and sounds fantastic. I could never go back to the weedwacker-sounding stock pipe. So yea it's mainly to sound cool, but there's some power added.
Hey Will,
I just set up my bike using a used engine and went to the SBP chamber with no experience of the regular set up. I also put on a Jag CDI so again I don’t know how the stock one would have run. I notice that my bike is also very poppy in the lower RPMS but smooths out nicely once I use more throttle.
Does yours do the same? I’ve asked this question in another thread but not directly to someone who runs the same pipe. I would like to achieve that same smooth feel through all ranges but have no idea if that is expecting too much / or how to get there.
Thanks,
Rich.
 

sub66

New Member
Apr 25, 2014
140
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canada
the stock pipe w let my mother down.

i had issues w low end and to much a narrow hit. mostly because my bike is past stage3 and 66cc etc etc.

myself a i have been loving it with larger stinger in silencer and longer too. leaving the snub 3/8 stinger welded on the pipe. 1/2" in silencer.
thats is a job left for bored people who can jet a carb. it just widens the hit cause the pipe will empty faster. getting it right is easy i think w an adjustable carb.

please dont run out and mess w exhaust because i said its possible... anything is possible....different uses and tunes cannot be generalized.
 

Moto

Member
Jan 7, 2012
403
15
18
San Francisco, CA.
In order to make use of a tuned pipe you have to rejet -- otherwise it will just sound different. Tuning is super super important. because an expansion chamber will flow more freely than the stock exhaust the engine will be able to use more fuel --> upjet. Upjetting lowers your fuel economy so sometimes adding a tuned pipe will too. However a lot of the time the stock #70 jet is too large even with a tuned pipe so sometimes if you tune your engine you will improve fuel economy because you downjet.

Case in point: I have a bike with a big expansion chamber with a 21mm carb and a #85 main jet which gets terrible gas milage but a little 50cc bike with a tiny chamber and a stock carb which gets over 100 on a #65 jet.