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Wrench
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355 Posts
Discussion Starter #1
Anyone used or dynoed these systems..........Looking at the bagger unit.

I really like the equal length headpipes, not many seem to pay attention to this on harleys.

And the header tubes are stepped in diameter, wondering why nobody seems to talk about them.

Bring it on:boobies:
 

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I paid.........did you??
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2,301 Posts
The Road Rage and the Fatcat are the only 2-1 systems with equal length header pipes and also stepped header pipes.

The Fatcat is the cleaner looking system, and I think that is why more people go with it. It also has a great reputation as producing great numbers with flat torque lines.

Steve
 

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917 Posts
I guess it depends on the model.

My dyna fatcat does not have equal length headers...rear is 5" shorter.

My dyna road rage does.

Both are stepped design.
 

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Equal length would only really matter if the cylinders were twins or 180 opposed. The V-twin cylinders are only alike in size, there are a lot of differences. it is more like 2 seperate engines. No matter what you do, you will never get each cylinder to work the same as the other, so the pipe is a non issue.
 

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"What's this do?"
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route66paul said:
Equal length would only really matter if the cylinders were twins or 180 opposed. The V-twin cylinders are only alike in size, there are a lot of differences. it is more like 2 seperate engines. No matter what you do, you will never get each cylinder to work the same as the other, so the pipe is a non issue.
I wondered about that.
 

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wanderer
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172 Posts
here's my dyno with the road rage-04 flht 124 s&s 625 cam, heads ported by headquarters. the road rage pulls hard right off idle. View attachment 42843
 

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Let er rip!
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Obviously good numbers and a nice torque cruve! Sort of a crazy AFR deal going on though. Did they try any changes?
 

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wanderer
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I'm afraid I was responsible for the afr- I'm sure there is more to be had by rejetting
 

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Let er rip!
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That jump above 14 probably gets the plugs ready for the dip below 12 that's coming. Perfect!
 

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not to mention that different primary tube bend angles change the "effective" tuned length. So, the rear pipe might be two or three inches shorter and "appear" unequal to the front but in reality it may act as the same length due to the bend angles.

Not everything appears like it should be on the surface.
 
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