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Discussion Starter #1
I have a 2001 Superhawk w/ Staintune high mount exhaust. I just noticed something odd. At startup, vapor only comes out of the left side exhaust. Once the bike is warmed up, hot exhaust comes out of the left side, the exhaust coming out of the right cannister is much cooler.

Is this normal? Seems strange to me.
Mike
 

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I wonder if that "blockage" is there to compensate for the unequal length headers or the cooler-running front cylinder???
If they are noticably different after riding, then I'd worry about it.
 

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Discussion Starter #5
obstruction in header?

Does this mean that other Superhawk owners have noticed this? And where in the header is this obstruction located?

Thanks,
Mike
 

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Keep in mind that there are certain principles of exhaust building at work here. A blockage or divert can be a good thing in terms of the interference principle in gaining sufficient back pressure to increase mid-range or low end torque.

With dual exhausts, the point of bifurcation is very important as is the angle & any uneven pipe lengths can be compensated for by using a small amount of blockage.

Along those lines even a small blockage or divert of the flow can yield substantial gains or losses, so removing a blockage may gain you some top end horsepower at the expense of low end or midrange etc...

Just food for thought.
 

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My point of bifurcation is about 9-10 beers! Im not messing with that thing in the exhaust on my VTR. They put it in there for a reason. The exhaust seems even as far as I can tell.
 

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Discussion Starter #9
Even with the blockage to compensate for uneven lengths, doesn't it seem odd that vapor and heat are much more prevalent on the left can? In fact, I'm starting to find a sooty finish on the left turn signal, which is just above the left can. The amount of air coming out of the cans is roughly equal however.
 

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I find nothing odd with that at all. The rear cylinder on all twins runs richer than the front cylinder & the gasses are going to take the path of least resistance to get out.


Carbuerated twins generally suffer more from this than Fi twins, because the Fi twins can make provisions in the mapping to compensate for richer condition in the rear cylinder caused by engine heat being passed from the front cylinder & exhaust to the rear cylinder. Either way look at any V-twin motorcycle with dual exhaust cannisters & one will be darker than the other.
 
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