Naysayers please remember the above phrase when making blanket statements.
True duals are not ALWAYS detrimental.

 

I put on Fulsac's true duals for a few reasons. 1) cracked y pipe for the second time 2) getting into the cam chest is easier 3) sound (it is louder) 4) cooler at stop lights (500-600 rpms help also) As for performance, it is hard to tell. My bike is faster than it was but I also changed to Andrews gear drive 37G cams, changed the rear pulley to 66T vs the 70T that was on there (which should have dogged it out) & of coarse the TD's. I have noticed that when I ride I am never under 3k when accelerating unless I am behind someone & can't go any faster anyway. The only time I have really noticed any hint of it not wanting to go when I blip the throttle is under 70mph and it was just as bad before. Just drop down to a gear that will put your rpm's into the power band & go. Someday I want to get mine on a dyno (just to get the most out of what it has & the best mileage that I can get).

Toby

 

Show me a single dyno sheet where true duals outperform a two into one. I have not seen one yet.

 

As a general rule: 2-1 & 2-1-2 system produce more low end torque then 2-2 systems. Properly designed 2-2 system can produce more HP than a 2-1 or 2-1-2 system. 2-1 & 2-1-2 systems also work over a broader rpm range than 2-2 systems. Most Harley guys buy/run pipes for looks and/or sound rather than performance. Most aftermarket pipes will outperform the stock system. By how much in various/specific applications is always the question...

 

Sound. I am a post *****, lmao....

 

Sound. I had true duals, (V&H Dresser Duals..still got them) then went back to stock header with 4" Jackpots because I was on a torque hunt. I'm going back to true duals. MSGs to be specific because of the performance claims. One muffler on a bagger looks lame in MY opinion and doesn't sound that good either. I'm old and don't want loud, I want "good" sound out of my exhaust. True duals is the only way to get it that I have found.

mkguitar; what exhaust are you running?

 

On my evo FXRP a supertrapp 2/1. I needed the torque as I have a 15% overdrive. This bike weighs about 400 pounds- stripped. 80" high compression pursuit motor with cam. This 2/1 relieved about 15 pounds from the bike over the stock 2/1/2 system

the 95 FLHTC had stock header and supertrapp supermegs

the 2009 FLHTC has stock header ( no cat) with S/E supertrapp fatshots (modded; added disks, closed end cap).

...and on the 53 FLF...stock exhaust- which is a 2 into 1. ( yes I know, single muffler on a bagger...but that's how they came.) My other '53 and the '63 had same type system.

Here's the 53 FLF





Mike

( the trail 90 has a stock 1 into 1...1st production exhaust system with spark arrest!, the 74 Kawasaki 900 has a very very rare 4/1/4 by Nick Kemp)

 

To get rid of the cat. converter, don't you need to go with true duals or a 2 into 1 system? Also, isn't getting rid of the stock exhaust almost mandatory to getting a cooler running map & air box?

 

I had these on my last Ultra and really liked the sound and performance. Even if you aren't in the market this is a good read on exhaust and performance.
http://www.rbracing-rsr.com/

 

Lots of very wrong info so far. Blanket statements like 'they lose power' and 'they're very loud' are either misleading or just plain BS.
True duals with stepped headers do not 'lose' power. Particularly on an internally stock motor. You may feel a slight negative difference at very low (1500-2500) rpm's but there will also be a corresponding positive difference from 2000-2500 and on up - usually more is gained that was ever lost, power-wise.
Here is the correct 'rule of thumb': a 2-1 usually makes the most power, followed by the stepped header T-D, followed by the stock system with aftermarket slip-ons, followed by a stock system.
All of them also benefit from a better flowing air cleaner.