exhaust system for 2009 challenger

[Tfontenot]

I bought a 2009 challenger and I am wanting to change the stock muffler out with something that sounds a little better and I don't want to lose any HP if anything I would like to gain HP. I was told today by a owner at a muffler shop that he has done 3 challengers so far and that all of them were un-happy with the performance after the muffler change. The cars sounded great but all lost hp. One guy had gotten a dyno test before the muffler change and one after and had losed 60 HP. So he and one other guy put there stock exhaust system back onto the car. Has anyone hear of this happening to anyone else? I would really like to change out the stock mufflers with some flowmasters or something else for better sound but I'm not wanting to give up that kind of hp.

[Big Dodge]

See if mopar has something for ya.

[dwc43]

Look in the Mopar mags. Someone is selling them in there already.

[Slingshot383]

Did they just change out the muffler or did they also pull of the resonator? If you pull both the resonator and the muffler and replace with a Flowmaster single chamber or a Pro-Flow, you should see a net gain in HP.

[Century Cp Guru]

They are suppossed to Come with Flowmasters from Factory.

[aarracer]

You may have to retune to get everything in sinc?

[MOPEkid]

I know the 6-speed cars come without mufflers altogether and just a pair of resonators. You could give that a shot and see how it works. I agree though, I think a part of losing power (if that happens) would be needing a re-flash of the computer.