After months of extensive research, I just insalled a 2 into 1 Thunderheader. I am waiting for my PCIII and K&N ac from fuel motto to see how she runs.From talking to 4 different tuners and reading all the search topics I feel this will be the best set up for me.I really like the looks of the true dual rhinehardts. But with only a stage 1 upgrade I dont believe you will get the most out of them without going beyond stage1.I like alot of low end torque and duals just will not compare to a 2 into 1 system in that department.After I had a few conversation with Jamie from Fuel Motto my mind was made up.Give Jamie a call, he will give you not only his honest opinions but hard dyno facts.

 

True-duals need plenty of back-pressure to work well, from what I have been told, so free-flow mufflers will not give good results.

I don't like a loud bike and my factory fish-tails on true-duals look andsound good and the bike goes well too.

 

Additional back pressure will NOT improve true duels nor will it ever do anything but restrict the total air flow and there for power of any internal combustion engine. The whole idea of perfomance is to move as much air as possible thru the engine. A 2 into 1 pipe allows the exhaust stroke of one cylinder to help pull the exhaust gasesfrom the other. It's called a scavenger effect and helps to increase the total volume of air moving thru the engine. That's why duel exhaust on high performance cars has what they call a cross over pipe to help balance the exhaust. Once again ANY restriction to air flow, intake or exhaust, will cost power.

 

agreed-since i already have my hot rod bike - performance is not that big a deal to me on my ultra.i am going for looks - true duels is for me.

I know I am the newbie here, and to the HD world, but -

IMHO the horse power (and torque) differance(even though it would be slightly higher w/2 into 1's) would not be a"breath taking" performace differance ridingan800 lbbike. when you go from stock to either of these setups - you will get that noticable differance - gowith what you like.

Artie

 

I know what you mean. I've had D&D pipes on my SG since new, but still toy with the idea of T-rex or Rinehart true duals. Yes i'd give up a few points, but the sound and looks are still killer. I'mseriously thinking about duals with my new 124" motor just for the sound and style. Then when it bores me, i'll install the Boarzilla. Hmmmmmmmmm? Decisions decisions????

 

I have seen dyno charts that disprove this statement. They were testing drags. Merely putting a screwdriver in front of the tips of each pipe brought midrange torque numbers up.

I have fiddled with this concept for years on my bikes and can tell a difference on my butt dyno when I use a lollipop baffle or similar in my pipes.

I have lollipop baffles in front of the mufflers on my V&H duals. There addition made a great improvement on the bottom end.

[IMG]local://upfiles/17633/DF6FB897DD174F1CA001205C29476F47.jpg[/IMG]

 

Still have to stand by my original statement. Back pressure does not increase performance. If you put an engine on a dyno and test it with several different exhaust systems and make no other changes the dyno will only tell you which exhaust most closely matches your tune. If you tune the engine to each exhaust system you will get the highest numbers with the most free flowing exhaust. Pipe diameter, air velocity, cam duration and many other factors may determine where in the RPM band your power is made but the "need plenty of back pressure" statement thatI commented on simply isn't true.

 

Pros and cons? Better power= 2-1, Better sound= duals(IMO) , easier to take off to service right side of engine= duals, Better looks= 2-1(IMO)

 

Take a look at this post -

https://www.hdforums.com/fb.asp?m=2315404

Breath taking is a good word for the difference there in my opinion, night and day is another good comparison too.

Steve

 

Wow....I can read...

Hp for both set-ups are very close....

Torque though is impressive - 2/1 gains faster and stays up -theduels drop after a peaking - as the RPM'S increase....

can some one say newbie - [&o][]

Artie