I can def feel the difference in heat from catless pipes.

I just decatted my stock headers taken off my 17. Had them laying around so put them in my 2020. Of course I cant attest to how much heat is gone, since its cold now here. As far as sound, I think its a bit louder and deeper. Im running outlaw slip ons though, not SE. I did put the db reducer back in on the right pipe only. I also have a bit of back firing going on, so doing some auto tunes with the SE tuner soon to hopefully clear that up.

 

If I'm not mistaken, decatting the stock headpipe is gonna change the sound some but also drop some torque. Not trying to praise HD on their exhaust but the stock header along with the cat is engineered for backpressure and obviously some epa measures. On my 17 I did as a guy on the first page did, went with the FM 2/1/2 catless headpipe, and jackpot high rollers, they sound a bit louder, but not much than the SE street cannons. I loved it. Sound is also going change with a cam, which I did at the same time with a state II torque cam and a power vision dyno tuned.
I've done stage 1 on my 2020 RGL, with the same slipons that came off my 17, and the same VH aircleaner but using the HD tuner. That's as far as I'm going until warranty up or at least close to 2 years, then the head pipe coming off and the power vision coming out, along with a cam job.

 

If you run a decatted stock header, you'll need some back pressure. But the right slip ons can give you that. So its not a for sure that you'll lose torgue. Many ppl have opted to go this route versus buying after market headers, and have reported good results.

 

I decatted mine and it has a raspy sound now, but I will live with it. I improved the flow and got rid of lots of heat. I have a fp3 and I changed the map for a decatted head pipe so all is well.

I have Cobra Neighbor Haters.

 

I have Magnaflow Topgun 4 1/2" slip ons, everything else stock. It sounds good, nice deep idle tone, wakes up if you twist her, but not overly loud. It has a deep decel tone also. My dealer had multiple bikes with various slip ons, so I could compare side by side, the Magnaflow was hands down a better/lower tone on the M8 IMHO.

 

"In my head" I can think about going to AZ for a weeK and hook up with some brothers and be there. I am wherever I feel like at any given time.

You're trying to compare the heat of putting an S&S header on your bike to a de-cat of a stock pipe.. Nonsense. S&S flows more air which equals less temp. De-catting the head pipe doesn't increase flow a lick. Does a catalytic converter create heat, yes, but it's not nearly the same as a car.
Like I said, I believe most of this is in the riders head than anything. You put a loud set of slip-ons on a mans bike a 9 out of 10 times he's gonna say it feels faster when in fact it's usually not.

 

If I recall, FM did a stock headpipe against their header with the same muffler both times. Net gain was around 10/10. $tonecold and Cole did a decatted headpipe with the cam shootout and got very decent results. I have yet to see a decatted stock headpipe up against a performance pipe. Don’t think any of the manufacturers would do it, just in case the results are to close, and jeopardize their product sales. Most of the performance headers on the are very good, some better than others though, as expected. HD looks like they did quite a bit of testing on the stock pipe though, so until somebody does an actual dyno test, we are all guessing, lol.

 

I think the stock pipe is restrictive, its supposed to be (EPA). The HP/TQ can be brought up without doing anything except adding a tuner changing fuel / air ratios. All bikes will be restricted, from a dirt bike to a street bike.
We all know you can buy a car with 700+ HP in stock form, you pay for that too. Why HD doesn't come out with some 200 HP monster is beyond me. I know the tech is there, just look at the professional bagger race that just took place, those bikes were pulling 4th gear wheelies. So, it's doable and many people would pay the price. Check out the 17-19 min mark of this race. 75-80 mph and stand them up no problem.

 

Lol, don’t think they could get an air cooled vtwin to pass epa with 160 hp and not have reliability issues. They had the engine for that type of performance with the vrod, they were a blast to ride. In the early days of the vrod, someone posted a link to the patent bureau, there were detailed engine plans for a vrod engine in the 120” area. Never have been able to find it again after a couple of years. Still waiting, lol. All in all, unless they come up with some real radical engineering I don’t think we’ll see a 160/180 hp bike from the factory.