Exhaust pipes: 2-1-2 vs 2-2

[dlearl476]

There's folks that have played at that on dynos.

My personal experience with the RoadRacing (2-2) and a Galasetti (2-1) that I bought from Supertdejuc is that the 2-1 had a few more horses, but less torque, on the top end than the RR.  As 99% of my riding is between 3500 and 5K where the RR has more horses and torque, I'm running the RR exhaust now.

[brad black]

did you compare them with std headers and slip ons?

[dlearl476]

did you compare them with std headers and slip ons?

No, Brad, I didn't.  The bike had the RR on it when I bought it, and although I got the OEM set-up, I didn't really care because I knew I wasn't going back and didn't want to rejet for them.
I actually started dyno-ing my mods with OEM carbs/RR, then FCRs/Galassetti, then FCRs/Galasetti/Dynacoils, and finally, I still have to get a run with the FCRs/Dynacoils, and RR exhaust, then I'll be done.

[brad black]

i was just curious.  only change i've made to a 900 exhaust header wise was a backward step, but it wasn't that well conceived as a mod.

[hackers2r]

So has there been any further development on this issue?  I am debating how to do my exhaust at the moment.  2-2 similar to the Kaemna system, 2-1-2, or 2-1.  As far as I can tell, performance between 2-1-2 and the 2-1 should be the same if calculated correctly.  So in theory, it is a question vs crossover or no crossover.  Someone chime in here.  I thought an advantage of the 2-2 systems is the ability to tune each cylinder more accurately. 

[RB]

I am certainly not the authority on exhaust but I understand that for these engines if you combine pipes correctly it doesn't matter if it splits back out to two pipes. From what I have read the pipe that combines the two needs to be of sufficiant size. And I don't know what that formla is.
However, this may produce a different affect then not having any crossover or combining in relation to power.
Personally I like two pipes out but purely for easthetics.

[hackers2r]

I am looking to build a 2-2 system.  Can anyone chime in on how to properly calculate the necessary pipe length?  Not sure if I can use the traditional calculations that say the crossover should be 24" from the manifold.  In that case, would it be ideal to have the pipe for each cylinder including muffler be 24"?  Thanks.

[RB]

try Google for the exhaust length and pipe diameter calculator?



above is a link to a form that you fill out and burns stainless will give you back the info, they would like you to purchase your stainless from them when they do those calculations.
You don't want to put a muffler before the crossover, or move the crossover closer to the exhaust valve then the calculated 'sweet spot' for the crossover.  If space/length is a concern, then do not use a crossover. IMO, exhaust (on my bike) is a fine line between function and fashion. In other words, i am not going to sacrifice performance to have a 'cool to me' style exhaust if it isn't helping the engine, so extra design massaging may be needed to get to a compromise.