I'm wrapping up my LS1 swap - the car is running and pretty much driving (just needs a wheel alignment). It's an LS1 out of a 2004 Pontiac GTO with a TSP 224R cam. I currently have 2.5" shorty headers that connect to a 45-degree bend and basically dump the exhaust right under the footwell. Needless to say...it's LOUD! It sounds great, for what it is, but I need to tone it down quite a bit (I have to scream to talk to the person next to me).

I'm looking to retain the aggressive chop of the cam but just tone down the overall volume. I have cutouts coming, so I'll be able to open them up and get the volume when I want it, but if I left it like this, I'd go deaf in a month. Other than that, I had planned to just true duals and a muffler, but I'm wondering if that'll still be obnoxiously loud.

All this is to say, I want something that is acceptably loud, but not something that is going to kill my hearing and annoy the neighbors...that's what the cutouts are for.

Any suggestions?

 

Dynomax super turbos, more tame muffler and economical. I’ve got a set on my wagon

 

Dynomax Ultraflo's.

These are 3"

 

I like the Pypes Mufflers I have on my Monte SS.

 

Borla Pro XS

 

I second the Borla's.

 

Basically any muffler will tone it down. Which depends on the owners ear

That said, I install alot of flowmaster FX, magnaflow and borla mufflers at my shop. The larger the muffler case, the more it will dampen the noise. If the tone is appealing, but still too loud, add high flow cats. If there is drone, read about J-tubes/helmholtz tubes

 

Lawrence LT Tolman on YouTube has an excellent video on the drone cancellation with the j- pipe like what Pocket mentioned.

Resonators might me an option too.

 

Flowmaster Super 40's

 

Except for the Series 10, the Series 40s are the loudest Flowmasters there are plus they DRONE. Not sure it's what OP is looking for

 

If you want something more unique sounding at a reasonable sound level I really like the Spintech Pro Street 6000s.

 

damn mufler threads are always so subjective, whats loud to one guy is mild to another. really op go do some youtube listening and try to find something you really like in a similar car as yours to get some ideas. i know that sounds like an easy out but it may give you some ideas for what you consider (good sounding/or too loud). and i do agree with the above spintechs sound really good.

 

Understatement of the century right there.

 

I've got QTP screamer mufflers on my CutLS. They are a turbo muffler but have the cut out at the back of the muffler that dumps out before the axles. Anything you do, the farther the exhaust exits away from the cab, it's going to quiet it down.

 

Been running Magnaflow in all my cars since 2004. Not obnoxious and sounds HEALTHY! I also run an X pipe in my setups or dual into a single Y pipe (all from Magnaflow or Burns (Ypipe).
If you don't own a TIG welder.... now may be the time to justify buying one if you are doing it in stainless. YESWELDER is a great value for the hobbyist.

You never mentioned what car this is? Dual 2.5 into a single 3" is about all you need for 400rwhp. Great ground clearance also.

 

lol color me a hack, but I MIG weld all my stainless exhaust systems with pride! and use standard wire for extra hackishness.

 

Flowmasters belong on trucks in trailer parks. Not on a car looking for performance.

 

Another vote for Magnaflow!
I mig my stainless exhaust with stainless wire.

 

I know magnaflows are good i just never liked the sound. I had a Borla Pro XS on my stock 2006 silverado 5.3 not much louder than Stock muffler straight through design. I have flowmaster knock offs(they were on the truck when i bought it) on my 92 silverado cam and heads 1 3/4 headers no cats 2 1/2 inch dual exhaust. Idle nice rumble, cruising very little drone, wot very loud.I know flowmasters aren't the greatest muffler for power but they do sound good. I had a Corsa sport catback on my 05 GTO with long tube headers and high flow cats. Nice idle zero drone and very loud at WOT. The sound is a little higher pitched. The best i heard on a GTO has long tube headers high flow cats and borla catback. Not sure how it sounds inside.

 

https://www.hotrodders.com/threads/q...52261/#replies

Click on above and read post #16. That's what I did. Sound great and they last because they are Stainless Steel.