I have an 06 SG. The only thing that has been done to it is the addition of Stage 1 intake, Thunderheader slip ons and a Cobra FI fuel management system. Oh, and the Stage 1 download at the dealer when the intake went on. My question is this: I got a little bit tired of the noise the thunderheaders make so I was going to put the stock slip ons back on. However, while nosing around the dealer one day, I noticed a pair of 07 bagger slip ons. They appeared to be less restrictive than my 06's. I asked my favorite mech and he said they were less restrictive and would work on mine so he gave them to me. Do any of you know of any problems with putting them on with the stage 1 intake and Cobra setup? Will less restrictive exhaust hurt the SG with the stage 1 intake on it? It seems to run fine. I have not taken it for a drive, though.

 

After several attempts at getting decent performance along with quiet mufflers (ear problems), I installed a set of stock '07 Ultra mufflers (65846-07 and 65538-07) on my '06 Ultra with a 95" build kit. They are quiet at idle and cruising and have a little bark around 3000 rpm. They are a little louder and deeper sounding than the stock '06 mufflers. I just got back from a trip with a friend who rides a stock exhaust '06 Ultra where I could compare the sounds. If you look into the rear of the left muffler on the '07s, you will see that it has what appears to be a closed baffle with holes along the sides - sort of a dummy muffler.
I am also running a PCIII along with a K&N AC. I took off a set of SE street performance mufflers (80491-07) because they had a resonance under load that racked my messed up ears. I can't comment on the performance difference between the stock '06 mufflers and the '07 ones since I bought my bike used w/o the OEM mufflers. Overall, the '07 mufflers are a little louder than the '06 ones and probably flow a little better.

 

Sorry, I didn't answer your question properly. Putting the '07 mufflers on your bike should not hurt since you have a stage I download and a fuel mgmt system already.You may need to tweek the Cobra FI for optimum performance if you can do that.

 

You also might want to try modified stock mufflers from B&E performance. You can find him on Ebay as Bobvic2. I have a set on my 06 SG and have been very happy with th eperformance and sound. Not very loud at idle and nice bark when you get on the gas. I also hav ethe stage 1 and K&N filter. Bike runs great.

 

Pull the plugs and look at them. That'll tell you how the engine's doing...