I thought the same thing so I called them and asked about that and the dude pretty much admitted to me that what I'd be getting was a de-gutted header. After the convo I just did the removal on my stock unit. The cost to ship them mine in exchange for a gutted header was ridiculously tedious.

 

You can toss out the American Custom charts, as the baffles in the mufflers have been changed. Both FuelMoto and Fullsac have posted charts comparing a stock bike to stock except for the addition of their catless headpipe. In both cases, the change results in about 5hp and 5ft-lbs to the good with the addition of their head pipe. FuelMoto's comparison is attached below.

That doesn't mean that losing the cat makes any difference. Quite the contrary, both Fullsac and FuelMoto have spent a ton of engineering time designing their pipes, and they produce more power because they do a better job of flowing the spent charge from the engine.

Until you get into a big-inch, high-lift, beast of a motor, the catalytic converter presents no meaningful flow restriction. If the heat from the converter bothers you, change the headpipe. You'll get a tiny bit more power, and your right foot won't get quite as hot.

There is ample testing showing that removing the converter from a stock headpipe not only doesn't gain you any power, but actually will make the bike run less efficiently due to the crosstalk between the two poorly-placed oxygen sensors.

 

Fullsac actually did a back to back, with and without cat in the stock headpipe and observed "0" difference in tq/hp, no other changes. FM did a test that showed 3-4 hp/tq, but there were mufflers involved also. To increase noise and decrease heat, it's a great cheap mod, but if you're doing it for performance it's a waste of time. You'll get plenty of opinion on the topic but you asked for facts so here is a fact; anytime you change ANYTHING in the intake or exhaust you modify the engines volumetric efficiency and thereby its fuel requirement. So then tuning is the opinion part, deciding for yourself weather or not it is important to you for your engine to operate at peak performance. I'm done debating the cat restriction thing, I've made up my mind that in the intended stock displacement or slightly larger, the cat is not a restriction, and it is important to me to have an actual tune, as oposed to a canned map or inline device that only adds fuel in the closed loop sector of the map.

 

Very interesting post - very much in line with what my suspicions were - but I will continue to search for the "smoking gun" dyno chart. Not that I am doubting your post, just to satisfy my curiosity.

It is not clear from the graph you posted what is being compared - and which set of data belongs to which test - can you clarify that please?

Your comment about cross talk is also interesting. I understand what cross talk is and the implications on closed loop control systems, but there seems to be a contradiction. On the one hand you are saying the cat places no significant restriction unless you are running a big engine, but on the other hand it is making sufficient difference to cause cross talk?

 

Inclined to agree with you entirely

 

You'll find the charts and explanations here.

The converter helps keep the flow separated so that the front O2 sensor only reads the front cylinder. If you look at a cross-section of the converter, it's a honeycomb. So that helps prevent the crosstalk. Remove the converter, and the two O2 sensors are together in a large, empty collector. All one needs to do is look at the photos people have posted of the inside of their pipe after they've removed the converter, it's painfully obvious.

As Fabrik8r said, the single best thing you can do for your bike in terms of performance, efficiency, and heat control is tune it properly. That does not mean adding a few resistors to your O2 leads to "richen it up". That means either tuning it yourself or paying for a tune. My Stage 1 103 would walk away from CVO 110 bikes, and would return 46-48mpg in the process. It's all in the tune.

 

Well, here's American Custom's chart anyway... Keep in mind, this is on a 09 RK which has no CAT.

 

I'm not so sure that I buy the arguement that the cat prevents the crosstalk issue. When I took mine out, there was a good 2+ inches of open space before and after the honeycomb material available for crosstalk. So the difference would be between ~5 inches of open space and ~11 inches of open space available for crosstalk. I don't see how it could make much difference if the first thing it hits is open space right from the factory. I still have my original one just in case...

 

I'm not saying it doesn't happen with the converter in place, just that it's worse without. The location of the 2010 & up O2 sensors is far less than optimal.

 

My 2012 Ultra Limited has the cats gutted. I put 5000 miles on it before they were gutted and there is a big difference in the heat as far as I am concerned. If fact I do not feel any heat in the current configuration. Now it has not been 80-100 degrees out since then but I think it worked for me.
I asked the mechanic how the O2 sensors were going to react wiht this done to the stock header...they said do not worry about it.

Throttle reponse seems better...the bike has not been on a dyno to see how much difference it made. I also have a deeper exhaust note with the stock exhaust. I like it now...where I hated the sound before.

The mechanic at the dealer said he took a 96CI run it before and after gutting the cats and got 6 more HP out of it.
I think I believe it although I did not see the dyno chart, so techically it is hear say.