http://www.americancustom.com claims that you can put on their headers and mufflers and don't need a remap? Here's the tech article that makes the claim: http://www.americancustom.com/media/news/AmerCustom.pdf

What do you think?

 

I think when they roll off the showroom floor they're in need of a remap, but that's just me.

 

x2 no way adding an exhaust system can make the tune go rich

 

That is correct. The ECM will adjust back to normal. But I have to agree with Gearhead, normal is not particularly good.

 

I believe the mufflers make less difference in total airflow , than a high flow air cleaner assembly.
In my case , on my old bike 06 FLHT (carb) , I added a set of V&H Classic straight cut slipons to my stock setup. This may have added a little power , but the sound was nice.
I then added a Big Sucker intake and the bike went lean.
I jetted the carb and had a very nice increase in power and fuel mileage went up.
Thinking about this I went back to the stock mufflers and all it seemed to loose was the noise.
Power was still pretty good also.
My current bike , I added S&S SPO mufflers with quiet baffles to the stock setup and it sounded pretty nice , but the power wasn't much better.
I then added an S&S teardrop intake , and it felt a bit weaker than before.
My dealer service guy said for me to try the stage one download and give him an honest evaluation , as he actually listens to me.
I did a bit of research on the stage one download and it didn't add much fuel , but ran a more aggressive timing curve compared to stock.
Well , I must say it worked for me just fine , more power , smoother , and my fuel mileage went up as did my last bike.
So I really think the intake makes more difference than the exhaust on a stock layout.
Personally I would do the stage one download anyway and you should be pretty well set unless you have wilder notions about further mods than a stage one.
My purpose to these mods were better performace , better fuel mileage , nicer sound , and total reliability down the road.
Just my personal findings.
Mick

 

You can do it, no problem. You can always get into the stage I air cleaner and fuel management system later.