I have had both the 3.5s and now have the 4 inch ones on my Limited. I only kept the 3.5s on the bike for a couple weeks. Were they louder, yes, but the sound was a raspy nasty loud. Took a trip across the mountains with them and found them to be annoying actually. sold'em here on the site and put the 4" ones on. Much much better sound. A nice low rumble and much more pleasing to the ear. If you are just lookin for loud and loud is all you care about, the 3.5s will fit that bill.
Ditto here as well...... To each their own, but i like the 4" sound a lot better.....
I have had both the 3.5s and now have the 4 inch ones on my Limited. I only kept the 3.5s on the bike for a couple weeks. Were they louder, yes, but the sound was a raspy nasty loud. Took a trip across the mountains with them and found them to be annoying actually. sold'em here on the site and put the 4" ones on. Much much better sound. A nice low rumble and much more pleasing to the ear. If you are just lookin for loud and loud is all you care about, the 3.5s will fit that bill.
Yup, listened to them side x side at the dealer before I chose the 4". The 3.5" definitely have more crack to them.
Why do they say not to adjust the ECU for the slip ons on their website? I thought that was the point of stage 1, air intake/tuner/exhaust? Do you only do tuner if you change header pipes too?