Header Question
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Road Master
Joined: Apr 2010
Posts: 816
Likes: 3
From: Michigan
Header Question
Help me out here.
What are the advantages in using a new 2 into 2 header system (ThunderHeader etc.) over just de-catting the stock header on my '11 Ultra Limited?
What are these "Power Chambers" I'm hearing about?
What are the advantages in using a new 2 into 2 header system (ThunderHeader etc.) over just de-catting the stock header on my '11 Ultra Limited?
What are these "Power Chambers" I'm hearing about?
Elite HDF Member
Joined: Apr 2007
Posts: 3,766
Likes: 16
From: Roseville, CA
Decatting removes the restriction, however, the design of that opened-up chamber is not necessarily optimal. There may be compromises for making more power, throttle response, low end torque, high-end horsepower, etc.
An aftermarket system will have internal designs or "chambers" for optimal exhaust flow characteristics. There is a science to exhaust flow management, not just straightpipes for most vehicles on the street.
An aftermarket system will have internal designs or "chambers" for optimal exhaust flow characteristics. There is a science to exhaust flow management, not just straightpipes for most vehicles on the street.
Extreme HDF Member
Joined: Sep 2010
Posts: 14,744
Likes: 402
From: Phoenix '53, '88, '09 Big Twins
the performance advantage is that the bike will go much faster if your wallet is lighter, it takes extra power to move the weight of your money around...
there may be a marginal advantage to an aftermarket system over a stock header w/o cat.
it would likely be realized if huge motor modifications were made.
time and time again is has been shown that the stock header system on a bagger well complements a mildly built motor, cams and maybe headwork.
mike
there may be a marginal advantage to an aftermarket system over a stock header w/o cat.
it would likely be realized if huge motor modifications were made.
time and time again is has been shown that the stock header system on a bagger well complements a mildly built motor, cams and maybe headwork.
mike
Grand HDF Member
Joined: Dec 2007
Posts: 4,999
Likes: 55
From: Bay Area
You will get more low end torque because of the "scavenging" affect of the 2:1 pipes. One cyl uses the gas flow from the other cyl to help pull out the exhaust gases so there is less restriction in the exhaust system. On the other hand by gaining low end torque you will give up some top end power, a fair trade off given these behemoths are not made to run like a crotch rocket on the autobahn.
Elite HDF Member
Joined: Apr 2007
Posts: 3,766
Likes: 16
From: Roseville, CA
there may be a marginal advantage to an aftermarket system over a stock header w/o cat.
it would likely be realized if huge motor modifications were made.
time and time again is has been shown that the stock header system on a bagger well complements a mildly built motor, cams and maybe headwork.
mike
it would likely be realized if huge motor modifications were made.
time and time again is has been shown that the stock header system on a bagger well complements a mildly built motor, cams and maybe headwork.
mike
Intermediate
Joined: Sep 2010
Posts: 36
Likes: 0
I'm not sold on the X pipes. That whole idea originated from nascar. I does work on v4,6,8 engines that have constant opposing forces firing but the V twin motor does not run in this fashion. all the dyno charts I have seen are comparing the x pipes to stock head pipes with cats I would like to see a comparison between x pipes and de cated head pipes. For the money and the power gains you have to give V&H credit for some real good marketing.
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Grand HDF Member
Joined: Dec 2007
Posts: 4,999
Likes: 55
From: Bay Area
I'm not sold on the X pipes. That whole idea originated from nascar. I does work on v4,6,8 engines that have constant opposing forces firing but the V twin motor does not run in this fashion. all the dyno charts I have seen are comparing the x pipes to stock head pipes with cats I would like to see a comparison between x pipes and de cated head pipes. For the money and the power gains you have to give V&H credit for some real good marketing.
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Road Warrior
Joined: Jun 2008
Posts: 1,437
Likes: 80
From: currently an Okie
Difference?
The difference between a de-clawed cat and an X pipe is marketing.
You can bet Harley designed the 09 header to be efficient. Then in 2010 they threw in a cat, but it's the same chamber as the 09.
The people that bought in to the Marketing hype of Fulsac and Fuel Moto are going to be adament defending their investments, but in reality, there's no way the added power you will get from them are worth the $450+ you will have to spend for their marketing.
That's the way I see it anyway.
You can bet Harley designed the 09 header to be efficient. Then in 2010 they threw in a cat, but it's the same chamber as the 09.
The people that bought in to the Marketing hype of Fulsac and Fuel Moto are going to be adament defending their investments, but in reality, there's no way the added power you will get from them are worth the $450+ you will have to spend for their marketing.
That's the way I see it anyway.
Elite HDF Member
Joined: Apr 2007
Posts: 3,766
Likes: 16
From: Roseville, CA
I'm not sold on the X pipes. That whole idea originated from nascar. I does work on v4,6,8 engines that have constant opposing forces firing but the V twin motor does not run in this fashion. all the dyno charts I have seen are comparing the x pipes to stock head pipes with cats I would like to see a comparison between x pipes and de cated head pipes. For the money and the power gains you have to give V&H credit for some real good marketing.
The difference between a de-clawed cat and an X pipe is marketing.
You can bet Harley designed the 09 header to be efficient. Then in 2010 they threw in a cat, but it's the same chamber as the 09.
The people that bought in to the Marketing hype of Fulsac and Fuel Moto are going to be adament defending their investments, but in reality, there's no way the added power you will get from them are worth the $450+ you will have to spend for their marketing.
That's the way I see it anyway.
You can bet Harley designed the 09 header to be efficient. Then in 2010 they threw in a cat, but it's the same chamber as the 09.
The people that bought in to the Marketing hype of Fulsac and Fuel Moto are going to be adament defending their investments, but in reality, there's no way the added power you will get from them are worth the $450+ you will have to spend for their marketing.
That's the way I see it anyway.
We all know there is less heat and more sound as well.