De-cat vs True Dual
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Cruiser
Joined: Jan 2012
Posts: 135
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From: Montreal Canada
De-cat vs True Dual
HI guys ... i know there is a difference between having the cat remove vs True Dual but can somebody tell me exactly the difference and why spend the extra money on the true dual ? Also the sound ??? Police around here is checking the bikes here and there. I know the the sound issue is betwwen the seat and the handles but still i wonder if I made the right choise by having the cat remove...ending up with brand new pipes (stock decatted). Waiting on the snow to get off to try the new mini apes, New A/C RC component, Power Commander V... with Rine Hart slip ons it should have waked up my bike... will post once the rain wash up the roads... thanks 
Extreme HDF Member
Joined: Sep 2010
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From: Phoenix '53, '88, '09 Big Twins
true duals is a separate pipe and muffler for each cylinder.
the stock ( and many performance headers as well) configuration is the 2 headers, from each cylinder, to a common pipe, then to 2 mufflers. ( "2-1-2" )
on cat model bikes ( 2010 and up, some 2009) the common pipe is where the catalytic converter is.
some feel that the sound or performance of a true dual set up is preferred.
not me, I prefer that the 2 cylinders be connected so that exhaust scavenging, and it's beneficial effect on performance takes place.
"True Duals" is a relatively recent fad, maybe driven by the marketing dept.
Mike
the stock ( and many performance headers as well) configuration is the 2 headers, from each cylinder, to a common pipe, then to 2 mufflers. ( "2-1-2" )
on cat model bikes ( 2010 and up, some 2009) the common pipe is where the catalytic converter is.
some feel that the sound or performance of a true dual set up is preferred.
not me, I prefer that the 2 cylinders be connected so that exhaust scavenging, and it's beneficial effect on performance takes place.
"True Duals" is a relatively recent fad, maybe driven by the marketing dept.
Mike
Last edited by mkguitar; Mar 9, 2013 at 08:44 PM.
Seasoned HDF Member
Joined: Feb 2008
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First removing the CAT's is a cheap work around but does not work well you will lose torque even if you tune to the change.
So called True duals are a selling gimmick, they may be ok on a big build that requires a lot of flow but on most not what an HD needs to tune and run it's best. They need some back pressure. The HD scavenging system really works well .
headers like the jack pot 2-1-2 boost performance, lose the Cats and are easy to get a good tune with.
I pulled the CAT on my 2011 while the bike ran good I was never able to get the torque I lost back. The common pipe where cat is just does not have the right flow when cats are gone. On the 2013 I gave up screwing around. Went with Jackpot 2-1-2 headers Some slip on I like and the power vision done no more messing around runs as it should
Stock header with cat cut out and re welded. Easy enough to do but not worth it IMO.
http://s259.beta.photobucket.com/use...0x480.jpg.html
So called True duals are a selling gimmick, they may be ok on a big build that requires a lot of flow but on most not what an HD needs to tune and run it's best. They need some back pressure. The HD scavenging system really works well .
headers like the jack pot 2-1-2 boost performance, lose the Cats and are easy to get a good tune with.
I pulled the CAT on my 2011 while the bike ran good I was never able to get the torque I lost back. The common pipe where cat is just does not have the right flow when cats are gone. On the 2013 I gave up screwing around. Went with Jackpot 2-1-2 headers Some slip on I like and the power vision done no more messing around runs as it should
Stock header with cat cut out and re welded. Easy enough to do but not worth it IMO.
http://s259.beta.photobucket.com/use...0x480.jpg.html
Seasoned HDF Member
Joined: Dec 2004
Posts: 7,934
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From: Bloomfield, NM
Gutted Cat, SE AC, Rinehart 31/2" and PCV. Bike runs great, sounds good and has more lowend torque than when I started.
There is a torque chart on the FuelMoto web page that compares a stock 2009 headpipe (no cat) to a 2009 with a Jackpot header. There is 1.8 HP difference and a couple of ft. lbs. of torque. Certainly nothing that would be noticed while riding, so don't let anyone blow smoke up your skirt about how much better a 500 head pipe is over a free gutted cat.
You will find, however, that you lose some low end when you go with the true duals.
If the police are checking to see if you are EPA compliant, the gutted cat will give no indication that you have made a modification as long as you leave the O2 sensor wires in place. Just disconnect them under the right side cover if you are running a PCV.
Bill
There is a torque chart on the FuelMoto web page that compares a stock 2009 headpipe (no cat) to a 2009 with a Jackpot header. There is 1.8 HP difference and a couple of ft. lbs. of torque. Certainly nothing that would be noticed while riding, so don't let anyone blow smoke up your skirt about how much better a 500 head pipe is over a free gutted cat.
You will find, however, that you lose some low end when you go with the true duals.
If the police are checking to see if you are EPA compliant, the gutted cat will give no indication that you have made a modification as long as you leave the O2 sensor wires in place. Just disconnect them under the right side cover if you are running a PCV.
Bill
Last edited by billnourse; Mar 10, 2013 at 10:11 AM.
I'm satisfied with the performance (HP and torque) of the stock motor, but I've had a few problems with the excessive heat issue, which is the only reason I'd consider decatting or replacement of the exhaust to a jackpot 2-1-2.
Just curious, is it really necessary to add a tuner with an exhaust mod like this? Will the stock ECM compensate for the changes in the exhaust flows?
Mike
Just curious, is it really necessary to add a tuner with an exhaust mod like this? Will the stock ECM compensate for the changes in the exhaust flows?
Mike
Road Captain
Joined: Aug 2011
Posts: 516
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From: Grand Island, NE
MGS True Duals is supposed to not drop your lower end... or atleast thats what they're advertising. And they say they can beat the thunder header exhaust in performance
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Cruiser
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From: Montreal Canada
Thank you guys ... many opinion here ... ill be good to update you guys in about 2-3 weeks from now it is getting warmer every day cant wait
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From: San Diego
If you just remove your cat, there will probably be no need to add a tuner, however, with the cats gone, you can add some simple Vied's to add some more fuel, and make your bike run much better.
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From: Western NY
JG