I don't know if they are "So Great", and much as there is so great of a demand for them. The demand being looks, and less heat on the right side. This translates to more heat on the left side too. For the past five years Ihave a been a True Duals guy. I've had Rineharts, Hooker, and the Torres Concepts Conversion Kit with both FullSac mufflers, and D&D Police Interceptor slip ons. I even had a set of D&D FatCats in there for about a week.

With my mild build the True Duals made the bike much louder. So much so that in my "old age" I wanted a little less noise. So I just went back to the OEM "Y" Pipe and the FullSacs to give the bike a more OEM look, and hopefully draw less attention to myself. The bike is quieter, or should I say more muffled. The FullSacs are straight through free flowing mufflers, so I know there is less restriction, the only difference in sound being that the "Y" pipe makes it quieter. Ifthere is a loss or gain of HP or TQ, I can't feel it.

The heat is a bit more noticable, but with a better flowing build and good fuel management from Zippers, it's not anywhere as bad as it could be. So I'll run this configuration for a while.

 

The best reason to get rid of the stock "Y" pipe is because they SUCK, SUCK, SUCK to remove and replace for the do it yourself mechanics like me. If you're paying some HD mech to do it for you, keep em.

BTW: over on HTT a few years back I read some posts where a dyno tuner was getting 4-6 more horse out of the stock Y pipe setup [with quality slipons] by removing the metal pipe section that protrudes into the front header run. I had swapped my ProPipe onto my roadglide and needed to put the stock Y pipe configuration back on my FLHT recently so I took a sawzall with a metal blade and cut out a wedge of the protrusion...then used my dremel tool with grinding stone to taper the edges back into the Y pipe. I don't know how much of a difference its going to make on a dyno, but swapping back from the ProPipe to that setup didn't seem to hurt the performance of my FLHT at all that I can tell...That bike just screams up to 95mph.

 

Smitty, I'm glad this is just your opinion

there's ONE reason Irun true duals:
it's because ILIKE THEM
oh goody, now I can type I Got True Duals

 

http://i245.photobucket.com/albums/g...C/DSC_0042.jpg
http://i245.photobucket.com/albums/g.../fullflhrc.jpg
http://i245.photobucket.com/albums/g...ogsonflhrc.jpg

I like the balanced look, but I did not like the sound or the performance. Bub7 TD (stepped header) with TD fixed it.

 

Right on! I agree. Those with true dual claim performance but 2-1 is superior due to the scavenging. I have a Ghost pipe for the Dual exhaust looks and a 2-1 for perfomance!

 

it's my understanding also that the other part of scavenging on a 2-1 orcrossover pipe is the exhaust pulse from one cylinder creates a vacuum effect in the pipe to help pull/scavenge the exhaust gas from the other cylinder. your comment about longer pipes being less efficient makes sense, as the exhaust flow would lose velocity over distance, making itless effective.

I love the performance aspect of 2-1 pipes, but I will eventually be going with true duals cause I like the cleaner look.

 

Back around 2000, Harley must have changed the vendor for their Sportster pipes. The cross over began protruding into the exhaust pipe by a large amount. It probalby blocked 30% of the pipe! I'd say that would show up on a dyno. I haven't looked at the pipes on my Ultra yet, but I've often wondered if the situation was as bad. If you can clean that kind of mess out, there's some cheap HP to me made.

 

The true duals will gain some top end power. But all of the tests I have seen show that they are down on torque below about 4k rpms. The area under the curve, or average, is better with the stock setup. Most of your riding is done below 4k rpms so I dont care what a set of pipes makes above it. There will be individual bikes that are the exception but for the most part true duals hurt your bottom end. power.

 

I know I'm talking apples vs oranges here, but making power from V8 engines is what I'm experienced with. If you want to get the most power and best performance out of a V8, you need a crossover pipe. I'm not talking about peak/spike power here, but usable, "best performance results" power. H-pipes work, X-pipes work better. A real world example of this is fact that every NASCAR race car has an x-pipe incorporated in its exhaust system. With a V8, the crossover pipe balances the exhaust pulses and scavenging of the two banks of cylinders.

 

The prize goes to Hoffy. A cross over pipe aids exhaust scavenge which creates a low pressure zone in the cylinder during the overlap timing on the transition from exhaust to intake stroke, allowing better cylinder fill. Better fill means a larger volume of fuel/air, & a more powerful power stroke.