Question about 2 into 1 pipes
I have 2008 Fat Bob with Cycle Shack 2.5" Slip-ons, SE Stage 1 Air Cleaner, and a Power Commander V. I plan on doing a 103 Big Bore kit over the winter.
I know that 2 into 1's are better for overall performance of a bike. A local shop owner suggested using Vance and Hines Pro Pipes for the best performance. So my questions are...
Do I lose any performance with the 2-1-2 tommy gun exhaust on my Fat Bob in comparison to a straight 2 into 1 exhaust? I do like the look of the tommy gun exhaust.
Is there a substantial difference between 2 into 1 pipes? (i.e. V&H Pro Pipes vs Thunderheader vs V&H Big Radius 2 into 1 pipes)
I did try to do a search looking for other threads but I really wasn't able to find the information I was looking for.
Sorry in advance for my newbishness!
Thanks!
Here's a pic of the Bubs...
I have 2008 Fat Bob with Cycle Shack 2.5" Slip-ons, SE Stage 1 Air Cleaner, and a Power Commander V. I plan on doing a 103 Big Bore kit over the winter.
I know that 2 into 1's are better for overall performance of a bike. A local shop owner suggested using Vance and Hines Pro Pipes for the best performance. So my questions are...
Do I lose any performance with the 2-1-2 tommy gun exhaust on my Fat Bob in comparison to a straight 2 into 1 exhaust? I do like the look of the tommy gun exhaust.
Is there a substantial difference between 2 into 1 pipes? (i.e. V&H Pro Pipes vs Thunderheader vs V&H Big Radius 2 into 1 pipes)
I did try to do a search looking for other threads but I really wasn't able to find the information I was looking for.
Sorry in advance for my newbishness!
Thanks!
Then the 2 into 1 will still out perform your stockers.

The question is, do you really care that much? Is it enough 'performance' to offset the cosmetic difference you prefer? My neighbor took his 2 into 1s off. Didn't like the look. They were the V&H Pro Pipes. He didn't like the sound at low RPMs, either. Now he's got the V&H long shots. I think they're long shots. Equal length. Whatever. I know he pisses the OL off every now & then when he cranks it up early in the morning or late at night. But she likes him, so she doesn't stay POed for very long. Amazing that somebody you like can do something and somebody you don't like can do the same something and your reactions are different. Human nature.
I too like the look of the Tommy Gun exhaust. I think it looks badazz. Some 2 into 1s look pretty decent while some look like the back of my nutz. But none of them look as good as the TGs.
As far as which 2 into 1 performs best? Who knows? Who can tell? It has a lot to do with your bike and how it's tuned. One set might perform better on one bike and not perform as well on another.
Good luck in your decision making.
Very confusing.
It probably doesn't.

this note below is from their product page:
Pro Pipe Hi-Output is a purpose-built addition to the Pro Pipe family of 2-into-1 exhaust systems. Every aspect of Pro Pipe Hi-Outputs design is singularly focused to yield maximum horsepower by improving the volumetric efficiency of heavily modified engines.
After countless dyno tests Pro Pipe Hi-Output was built utilizing tuned length headers that step from 1-3/4 to 2-1/4 to optimize exhaust gas velocity and scavenging while also maintaining the perfect balance of exhaust back pressure, assuring crisp throttle response and maximum roll on power. In addition, the merge collector features handcrafted internal knife edging to further improve scavenging efficiency through the collector.
Following the collector, the megaphone immediately tapers out to a 3-1/2 muffler body that expands to 4 1/2 for increased baffle area. Our exclusive Vance & Hines baffle features reverse cone engineering that allows maximum power yet omits the perfect exhaust note rumble for any hi output motor. Keeping its focus on performance, Pro Pipe Hi-Output retains the signature cues of the Vance & Hines Black Line with its high temperature ceramic coating and contrasted machined billet end cap.
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The exhaust gets more important as you go up in displacement. At 96 inch, there is no real difference between pipes, more power here, less there, Sound and style differences yes, but street power not really. I'm not sure even at 103 or even 110 inch if there is much of a difference, but a bigger exhaust on a bigger motor makes more of a difference.
If you are looking for max HP, go with a 2-2 and ride at higher RPMs. 2-1 typically make more torque at the lower rmp, but then have an annoying dip in the middle RPM ranges.
If you intend to keep running closed loop (and you should), stick with the stock head pipe if you like its looks. Some of the aftermarket stuff places the O2 sensors poorly. I think you won't loose any power even at 103 inch. The CVOs are 110 inch right? They use the same head pipe with cats welded in.
The reason it doesn't make much difference is that any HD exhaust is way too short, so you are just making a bad situation a little worse or better. Its still a bad thing and won't effect much in the end. Many of the dyno charts comparisons have a stock bike set up compared to the new pipe plus tune... and most, if not all of the improvement is due to the tune.
If you want that last 1 HP, however, I noticed that even the best pro tuners disagree on the best pipe, they each have their favorites to tune, and it varies from motor to motor, and tuner to tuner and month to month. Just saying, on a late model, you should be more concerned about style and sound than anything else until you are well over 110 inches.
Last edited by ColdCase; Oct 14, 2010 at 11:24 AM.


