Im in need of some super quiet performance mufflers. I need to be stealth. I'm planning on having a switch inside that will open electric cutouts going to some SLP loudmouth's when I want noise. This is in addition to the cutout going in the downpipe for track use. Giving 3 exhaust tones total. Im planning on using a resonator and cat as well in the stock locations. Thanks guys!

 

They make silencers for atv and dirt bike mufflers, you may be able to fab something up such as that. Other than that I would say the bigger the muffler the quieter itll make your car... although I wouldnt know where to mount something like that!

 

Dynomax VT... Just installed yesterday and they are super quiet at idle and through 3000 rpm. Once I let it rip though they are 100% as advertised as they get aggresive. When cruising, I never noticed my tires were so loud on the road before because I cannot hear anything from the exhaust. Also there is absolutly zero helicoper noise when 4 cyl mode is on.

 

If you want quiet STAY AWAY FROM THE MAGNAFLOW! Make a custom exhaust with the longest high flow resonator that can fit. I replaced the resonator on my magnaflow with a 22" one I believe. I think the next size up is a 24" I wish I did that one. Mines still loud but with 95% of the droan gone. Sounds like you are doing a lot of custom stuff anyways just becareful of the droan because it ruins the car. I believe there is a post on the G8 board about droan issues and you should find it. Its a very interesting read. If you look enough you will find some stuff on a BMW web site about it too. Having an electric cut out is cool for the sound but not for everyday driving. Good luck.

 

I intend to only use the downpipe cutout at the track. But otherwise there's going to be a valve that opens up to some some crazy loud SLP loudmouth mufflers. That's a good idea with the big resonator either way because the SLPs will still be really loud.


What brand resonator did you use, I know magnaflow makes them and their quality is unquestionable.

 

I used a magnaflow resonator. You can buy all the exhaust components you need from summit. Magnaflow makes good stuff but they do have alot of droan. The droan will make you miserable and your gonna hate driving the car. The longer the resonator the less droan youll have and thats the cheapest fix. Pull up an exhaust for a BMW or a Porsche and you'll see some wierd stuff but its all done so you get maximum sound with zero drone.

 

Walker DynoMax Super Turbos

 

Just talked to Dynomax/walker...their walker line is stock replacement. But the super turbo is the quietest high performance they've got...any other brand suggestions?

 

Havent heard or used them before on an ls4 but Corsa if you wanna pay big bucks or Borla used to make a Wbody exhaust. Since your gonna have the cut outs I'd stay away from loud mufflers. Before you needed to be loud to get gains. With the technology now you can get some free flowing mufflers that are relatively quiet. Dont know if you have a family but if you do they will thank you.

Do a youtube search you can find practically anything on there. You'll get an idea on what it will sound like. BTW mine is not that quiet even with the longer resonator.

 

^^i need to be stealthily quiet because I'm always driving in the middle of the night on weekends. Since I've got a loud exhaust the cops in my town have started following me around which is really annoying especially since there no other traffic. I'm not willing to give up sound for everyother time I'm driving, but there's times when I need to be quiet in this car. I'm not really worried about performance with these quiet mufflers since I will be able to make it loud with the flip of a switch, or even bypass in front of the cat with the flip of another switch. I'm going to get a big *** resonator tho.

 

Why not run stock exhaust since you have a cutout anyway?

 

Stock was rusted out

 

ahhh i c

 

I think my Magnaflows are pretty quite. I recently took the res off and there wasnt a huge difference. there really isnt any drone on the highway

 

I have a magnaflow and I think its pretty loud and I have a longer resonator too. Maybe Im just getting too old?

 

I think my Magnaflow catback is pretty tame noise-wise.

 

maybe I think mine sound pretty tame with no resonator but they sound great when you get on it.

 

I'm running DT headers thru 3 in piping to a magnaflow straight thru , then y-pipe to 2.5 in on each side thru stock c6 Vette mufflers. I'm catless and there is next to no drone. It's really quiet unless your on it and the Vette mufflers don't seem to restrictive as they are 2.5 inlets.

 

Shoulda got the ones with the vacuum opporated dumps!

 

A few members who have heard my car,say its actually quiet for having a CAI, headers,& catback Magnaflows(no Res).