Power duals vs. true duals
Extreme HDF Member
Joined: Jun 2011
Posts: 14,731
Likes: 2,536
From: Mountain Top, Alabama
Don't worry about the "low end torque" how often are you down there around 2500 RPM when you really need a constant 90 ft-lbs of torque? True duals help high RPM horse power. Thats where the fun is! If you really dig cruising up mountain grades in fifth gear at 55 MPH build you engine around low end torque. If you like to get on the throttle and have some fun cam that thing for HP and let her breath with true duals. What do you want a Mack truck or a Mustang?
I like lower RPM riding and 6 gear with some grunt.
My 'King and I like to stomp and strut like Tennessee Walker Studs...
Road Master
Joined: Oct 2009
Posts: 785
Likes: 2
From: SE TN
True duals do sound better, especially if the bike has a cam upgrade - you get the recognizable lope. However, you do not get the benefits of exhaust scavenging of a 2-1 or 2-1-2 system.
As stated many times on here, usually the order for best power gain is:
1. 2-1 (D&D, Dragos, V&H Propipe, etc)
2. 2-1-2 (stock config, V&H Power Duals, Fuel Moto, Fullsac, etc)
3. 2-2 (V&H Dresser Duals, Rush TDs, Cobra TDs, etc)
Look at high performance builds and see what they run. I haven't seen one yet that uses true duals. The 2-1-2 is nice compromise, and for the most part it behaves similar to the 2-1. Both the 2-1 and 2-1-2 will be easier to tune with the CFRs than 2-2, but there are some one here who do have the CFRs with TDs and love them.
Make no mistake - these bikes are not Mustangs. They are heavy, low-rev, and high-torque. And they take some serious coin to turn them into performance machines.
As stated many times on here, usually the order for best power gain is:
1. 2-1 (D&D, Dragos, V&H Propipe, etc)
2. 2-1-2 (stock config, V&H Power Duals, Fuel Moto, Fullsac, etc)
3. 2-2 (V&H Dresser Duals, Rush TDs, Cobra TDs, etc)
Look at high performance builds and see what they run. I haven't seen one yet that uses true duals. The 2-1-2 is nice compromise, and for the most part it behaves similar to the 2-1. Both the 2-1 and 2-1-2 will be easier to tune with the CFRs than 2-2, but there are some one here who do have the CFRs with TDs and love them.
Make no mistake - these bikes are not Mustangs. They are heavy, low-rev, and high-torque. And they take some serious coin to turn them into performance machines.
Elite HDF Member
Joined: Jul 2007
Posts: 4,749
Likes: 16
From: sand mountain Alabama
On the track I want hp with high rpm's
On the street I want tq. usable power at my finger tips.
I want my numbers to start to pull good around 2,000 to 2,500 rpm.
I have had both, for the street you can not feel the difference. If you do you probably did more than change pipes.
On the street I want tq. usable power at my finger tips.
I want my numbers to start to pull good around 2,000 to 2,500 rpm.
I have had both, for the street you can not feel the difference. If you do you probably did more than change pipes.
Road Warrior
Joined: May 2013
Posts: 1,430
Likes: 55
From: Florida
My S&S Power Tune Duals have a smaller hidden crossover,most of the exhaust flow blows right by giving true dual sound, while still giving some volume(not sound,flow) and scavenging like a 2-1-2. I put the quiet inserts in the V&H turndowns for a bit more back pressure,theyre not very quiet thats for sure. The CFR's would probably have that deeper rumble tone.
Outstanding HDF Member
Joined: Feb 2007
Posts: 2,710
Likes: 6
From: Spokane, WA.
Well, I am having my bike dyno tuned on the 25th, with recently installed MGS true duals. I will post that in my albums.
While it's apple and oranges, I did have a dyno done with power duals and monster rounds, with SE255 cams, that sheet is posted in my my albums.
It will be interesting to see how the two dyno sheets look, taking into account that the
cams are not the same.
While it's apple and oranges, I did have a dyno done with power duals and monster rounds, with SE255 cams, that sheet is posted in my my albums.
It will be interesting to see how the two dyno sheets look, taking into account that the
cams are not the same.
Extreme HDF Member
Joined: Sep 2010
Posts: 14,744
Likes: 402
From: Phoenix '53, '88, '09 Big Twins
OP, my concern with the PD's is that IF the bike is lowered, on a right turn, the cover on the X pipe can hit hard enough to relieve traction from the rear tire=low side slide.
also the clamp on the crossunder should be oriented so that it can't dig into a speed bump and tear the pipes off the bike.
sound is subjective- we all like our pipes and hate the other guys
mike
also the clamp on the crossunder should be oriented so that it can't dig into a speed bump and tear the pipes off the bike.
sound is subjective- we all like our pipes and hate the other guys
mike
Tourer
Joined: Nov 2012
Posts: 331
Likes: 1
From: PHOENIX
Personally I like the clean and tight to the bike look of the V&H true duals for a dresser. On the PD I thought the crossover looked a little too sport bike for my tastes. Just my opinion. When I got them 6 months ago my HD dealer said he didn't like all the welds around the power chamber X crossover on the power duals and may cause issues down the road. Sure enough at the dealer this morning a guy in for service on his road glide had dropped his bike sitting still and the weld cracked and the pipe fell right off at the X.
Last edited by PHXBiker; Jul 19, 2013 at 05:49 PM.
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Elite HDF Member
Joined: Jun 2007
Posts: 3,873
Likes: 13
From: NW Arkansas
Well, I am having my bike dyno tuned on the 25th, with recently installed MGS true duals. I will post that in my albums.
While it's apple and oranges, I did have a dyno done with power duals and monster rounds, with SE255 cams, that sheet is posted in my my albums.
It will be interesting to see how the two dyno sheets look, taking into account that the
cams are not the same.
While it's apple and oranges, I did have a dyno done with power duals and monster rounds, with SE255 cams, that sheet is posted in my my albums.
It will be interesting to see how the two dyno sheets look, taking into account that the
cams are not the same.
Extreme HDF Member
Joined: Sep 2010
Posts: 14,744
Likes: 402
From: Phoenix '53, '88, '09 Big Twins
and not that It makes any difference to me...in theory, the system(s) work much like a 2/1 until the pressure of increased flow pushes gasses to the left side
mike