Sorry guys. Gotta ask... But rest assured, I will not be asking questions like "best exhaust for me" as that is up to me to decide.


I will be getting an exhaust shortly and looking at my different options is quite mind boggling. My question is this... With all the different exhaust types (NOT manufacturers) what are the benefits and drawbacks to them all? I see 2-1-2 true duel bagger style, true duel left and right side, 2-1. Clarification, PLEASE!!


I like clean lines so I am drawn to the "racer" duels (left and right side). I do not want so loud that I wake the next county up... I do leave for work at 4:30 a.m. But I do want to be heard when I ride... Loud pipes saves lives? I am not looking to build a power horse as I want to enjoy long trips without having to stop for gas every 30 minutes but a little more power than stock never hurt anyone. My pipes HAVE to be black...

 

I'm surprised nobody has commented back yet. I'll try to help you with my fairly limited knowledge.

Essentially the main difference you bring up is between True-Duals, which have one single, separate pipe for each cylinder (the "true" in "true dual"), and other systems which have an exhaust collector/exhaust scavenging crossover (the pipes connect at some point). This maintains back-pressure and helps exhaust speed (and all kinds of math I'm no good at). Any pipes with a crossover (2-1-2) essentially try to do the same thing as a 2-into-1 pipe, although most guys would argue they probably don't do it as well.

Simply put, a lot of guys like the sound of a true dual exhaust, but your low-end torque will probably suffer. Something with a crossover (ie: stock headers on all the Touring bikes) is kind of a compromise between the two, and shouldn't lose you any torque. You could just go with a slip-on and keep the stock headers, but if they aren't black then obviously you'll want to go with a full system.

Finally, a 2-into-1 will give you the best performance and the most torque, but don't really quite have the same sound as the true duals or 2-1-2. Personally, they're not my style either, especially on a bagger, but plenty of guys put them on and like them, so to each their own.

Hope that gives you a bit of an idea! Someone else could probably explain it better than I can.

 

BSA discovered by chance, back in the '60s IIRC, that linking the pipes from each cylinder on their parallel twins gave a boost in torque and all the other twin manufacturers quickly jumped on the bandwagon. That is probably why for many years Harleys have had a balance pipe of some sort on all their bikes.

The current touring 2-1-2 is the latest version and gives good performance and torque. You may be aware that most production vehicles worldwide with two or more cylinders combine the exhausts from each cylinder in some way, which is for performance reasons.

A 2-into-1 provides a compact system, while also giving scope for the best results IMHO. I had true duals previously and have had my book dynoed at the same shop by the same tuner with them and also my Supermegs 2-into-1. The headline numbers for both systems are very close, but the torque for the Supermegs is much superior from low revs right through to the mid/upper range, where most of us spend our time riding. An unexpected bonus is that the engine is much smoother running now.

So of the three basic options I suggest that a 2-into-1 is tops for performance, followed by a 2-1-2, with TDs last. I must say that I enjoyed my TDs, but I won't be going back!

 

Yeah exactly. All you gotta do is look at any Ferrari or other Supercar and see, are there 12 exhaust-pipes coming out the back, one for each cylinder? Or just 1 or 2? Well there's your answer for best performance.

That said, I still can't put one of those ugly 2-into-1 pigs on my road King, I'm not racing it I can live without the torque lol.

 

We offer two different systems you may be interested in: the Tru-Duals and the Pro Duals. A good deal of time was spent in R&D developing these, and we were able to use a tuned pipe length to see power gains which match that of a 2-1 exhaust. We also offer 5 different style of slip-ons that will match the sleek black appearance of either head pipe.

Tru-Dual:




Pro-Dual:

 

Kind of looks like the 12 in this Enzo exhaust sure doesn't come out the back as 12. Exhaust system engineering is much more complex than stating an individual pipe with no merging or balance tube gives superior performance. To answer you question, all the Ferrari's I've seen with a 12 cylinder engine, normally have 4 exhaust tip sticking out the back.

 

Thanks! I agree with you that the 2-1 doesn't look quite right on a bagger.


When you say that I will lose torque, how much are you talking? Would it be noticeable or would you only really be able to tell on paper? What would help mitigate that loss of torque with true duals? Cams?

 

Thanks for your input. I'm not out for a power horse, So I can say that the 2-1 is probably not going to be an option for me. I guess I need to consider the 2-1-2 or the true duals.

 

Thanks! Great looking set ups. I am drawn more to the Pro dual. I do have a question abut the route of the pipes. (Please forgive my ignorance on this. I am a noob, after all.....) Why are the pipes routed the way they are? Why isn't the rear cyclinder exhaust pipe routed directly out to the left of the bike instead of the right? Is this for performance reasons? Add the needed back pressure?

 

Great question, and you are correct! We route the pipes this way to manipulate their length, which results in a bigger power gain!