2-1-2 into 2-1 after de-cat
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From: Shenandoah, TX
2-1-2 into 2-1 after de-cat
I know there has been alot of people de-catting the stock pipes. I picked up a set from the dealer for free to play with. I have de-catted them and thinking of plugging the cross over or under in this case, and making them 2 to 1. My question is, has anyone done this, and what was the results?
I also plan on doing Xied and A/C. I now have everything stock exsept Sampson slip-ons. And I don't plan anyother mods, like cams or anything else.
Thanks for your help.
I also plan on doing Xied and A/C. I now have everything stock exsept Sampson slip-ons. And I don't plan anyother mods, like cams or anything else.
Thanks for your help.
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Joined: Sep 2010
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From: Phoenix '53, '88, '09 Big Twins
You can certainly do this, but the "magic" on a 2 into 1 is the tuned length of the F/R header pipes.
As much as possible they should be the same length where they meet, otherwise you get random wave pulses moving back and forth within the pipe- possibly causing a reduction in performance...at certain specific rpms
There is a lot of science- enough to let me know that I'll never be smart enough to understand it all
Probably better to get a 2/1 system from a 2010 FLHX and play with that--- although it is completely possible that H-D designed this with the concept that the cat would affect velocity and direction of gas flow and wave pulses
Mike
As much as possible they should be the same length where they meet, otherwise you get random wave pulses moving back and forth within the pipe- possibly causing a reduction in performance...at certain specific rpms
There is a lot of science- enough to let me know that I'll never be smart enough to understand it all
Probably better to get a 2/1 system from a 2010 FLHX and play with that--- although it is completely possible that H-D designed this with the concept that the cat would affect velocity and direction of gas flow and wave pulses
Mike
Last edited by mkguitar; Mar 17, 2012 at 08:22 PM.
Thread Starter
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Joined: Jul 2007
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From: Shenandoah, TX
You can certainly do this, but the "magic" on a 2 into 1 is the tuned length of the F/R header pipes.
As much as possible they should be the same length where they meet, otherwise you get random wave pulses moving back and forth within the pipe- possibly causing a reduction in performance...at certain specific rpms
There is a lot of science- enough to let me know that I'll never be smart enough to understand it all
Probably better to get a 2/1 system from a 2010 FLHX and play with that--- although it is completely possible that H-D designed this with the concept that the cat would affect velocity and direction of gas flow and wave pulses
Mike
As much as possible they should be the same length where they meet, otherwise you get random wave pulses moving back and forth within the pipe- possibly causing a reduction in performance...at certain specific rpms
There is a lot of science- enough to let me know that I'll never be smart enough to understand it all
Probably better to get a 2/1 system from a 2010 FLHX and play with that--- although it is completely possible that H-D designed this with the concept that the cat would affect velocity and direction of gas flow and wave pulses
Mike
I fully understand what your saying, and don't get me wrong. I'm in no way argueing with you. To the naked eye, the stock 2 to 1 and 2 to 1 to 2 look the same exsept the cross under is not there. Maybe wrong, that has happened before.
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From: Daytona, Fla.
When you opened the collector to remove the cat was the rear header extended further into the collector than the front header? The 2010 2 into 1 pipes are built that way to attain the equalization that Mike refers to. If yours is built that way it should work fine. I have a 2010 pipe on my '07. That was what I found when I removed the cat, & it works just fine.
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From: Shenandoah, TX
When you opened the collector to remove the cat was the rear header extended further into the collector than the front header? The 2010 2 into 1 pipes are built that way to attain the equalization that Mike refers to. If yours is built that way it should work fine. I have a 2010 pipe on my '07. That was what I found when I removed the cat, & it works just fine.
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From: earth
Didn't you say you got them for free to play with, just do it and find out. Use a temporary cap like a freeze plug or a silicone cap you can clamp on, if you don't like it, no problem, just uncap it.