Everything I have ever read and seen tells me a 2 into 1 pipe builds way more power than a 2/2 pipe. A 2/2 isn't any different than stock except the stocker has the crossover for deeper sound.

 

PerryRoss,
Very good article, thanks for posting this.
Graybeard

 

Not 'way more' on a stage-1 Dyna.

In my experience, a good 2-2 (e.g. not Short Shots) along with a good A/C and tune will net you about 10% extra HP & TQ. Change to a 2-1 and I think you'd be lucky to find much difference; it will be more dependant on the state of the tune. Might be lucky and find a couple of HP with a 2-1, depending on which one.

When you do a stage-2, a better pipe will help more and same as you do more work on the engine.

 

I don't get how a restricted stock exhaust is the same as an aftermarket free flowing 2-2. It has a lot more difference than just a crossover. 2-1 exhaust are more of a recent exhaust option. People have been making good power with a 2-2 for years.

 

peak numbers are misleading and if you rely on peak numbers your reading the Dyno wrong. A good 2-1 like the fatcat bring the torque range up closer to max throughout the torque curve. While it may only max out a couple ft-lbs higher it is how much closer to max throughout the curve that makes the big difference. The feel in performace on a street bike is the improvement in torque between 2000-4000 rpms. So say at 3000rpm the 2-2 is producing 50% of max torque, the 2-1 may indeed be at 75-80% or more. This is where the feel in performance lies... it is in the change in curve throughout the RPM range not necessarily the max mumbers. A full 2-2 will possibly change the torque curve more than a slipon thus you will feel it more or less depending on the system. One of the best(if not the best) choices for a 2-2 system is the Bassani pro streets. They perform great(although you'll still get more 2-4K torque with a fatcat and some other 2-1 pipes). A short shot may give more max than a slipon but may in fact feel slower to get there because the torque is reduced through the range and does not come on till later due to the systems design.

 

Definitely agree that a 2-1 is the way to go, but no way is a 2-2 the sane as stock.

 

2:1 is the way to go for performance. You can still expect about 5 hp gain from our slip-ons with the 2.00" baffle, when properly tuned.
-Ryan

 

I love all this 2/2, 2/1 jibber jabber if you baught a HD for performance you baught the wrong brand/bike. The difference you butt dyno will tell you is not much, I agree its fun to get the most out of these beasts and I have done somethings to mine as well and will do more in the future. But I think none of us baught an HD with and all out goal of performance. Go with the pipes you like the looks of you gotta look at them all the time and any full system is going to be better than stock or slip ons, get a good tune and you'll be happy. I donlt like the looks of 2/1 reason I went with 2/2 the minor power difference meant nothing to me. Some guys would would hang a turd around their neck if it was guarenteed they would go faster, me on the other hand would hang no turd around my neck. LMAO

 

I would love to see those numbers, just for curiosity.

I use to camp at lake puddingstone when we went to raging waters.

 

I assume you have a high flow air filter and your bike is flashed and/or mapped for it.

If so, go ride. IMO you're all set. If you're using your HD to full potential, and I presume you're not (it's HD, not built to race) then I would think about gaining horses.

Go ride dude... Fugetaboutit!!