ATR replacement muffler question

[PHINFAN]

Thought I would ask here, figuring somebody had this problem before. I have an ATR 3" dual exhaust on my GN. In my infinite wisdom 8 or so years ago, I went with the stainless pipes, but the mild steel mufflers, because I wanted it louder. Well 8 years later, the rest of the exhaust is fine, but the driver side muffler is rusted through, and ATR is gone. Anyone else have this problem?

What mufflers work good with this? Seems to be 3" inlet/outlet, both center, about 18" in length, any suggestions?

 

[79TurboCutlass]

If you want to quiet it down for normal driving check out Magnaflows. They are stainless steel and I'm sure you can find them the right size to fit in place of the ATRs. A friend of mine has a dual exhaust with Magnaflows on his T. Nice and quiet with no drone during cruising, but when he lays into it it sounds like open dp. Best of both worlds IMO.

 

[87NAT]

Here ya go: http://www.turbobuick.com/forums/general-turbo-buick-tech/288626-what-muffler-sounds-good-gn.html

Pack your lunch... its a long thread. See if you can figure out whats the "best sounding" muffler out there.

 

[PHINFAN]

I guess my question would be, don't I need to find a muffler that fits exact? Is there a way to make smaller/larger ones fit?

 

[TurboDave]

It should be pretty easy to find a muffler to fit the ATR system. You'll need to look for mufflers that are center in/center out (no offsets). My original ATR muffs rotted away years ago. Had some "race bullets" on the last few years and they're rotted away so I just put a pair of stainless Magnaflows on there. Most places like Jegs, and Summit sell mufs to fit the pipes size and orietation but for the most part the closest body size available is 14".
I believe the original pit bulls were 12". So you'll likely have to do what I did.
I'm too old to be working under there restling with mufflers etc. so I just took them to a local muff shop that I trust and had them do the install. $30 per side.

They did have to remove about 2" of the atr pipe to allow for the couple extra inches.

Round mufflers for a dual 3" system will be just a bit quieter than ovals, and will have less drone.

 

[rmar]

Borla is a good option that nobody ever suggest.

 

[TurboDave]

Borla is a good option that nobody ever suggest.

Yes that's also a good option. For those of you made of money!

 

[PHINFAN]

Thanks for the replies guys, one last pick your brain question. Is a "straight through" design a must? Do you lose that much hp without it? Change the sound?

 

[Monte231SS]

The ultra flows are a very good replacement for the pitbulls. I think they sound a little better and they have a nice polished look to them if you get the stainless ones. They flow well. I know 2 people that went with them and noticed no drop in their E.T/mph through the exhaust.

 

[PHINFAN]

Well, I ordered a polished stainless straight through set of magnaflows, that came as close to my dimensions as possible. I will be able to tell you guys how they sound compared to the pitbulls in about a week.

 

[TurboDave]

Which one's? Round (size) oval (size)

I believe the one's I just got are 4x9 ovals 14" long body.

The muff on the passenger side is VERY close to the front trailing arm bolt sticking through the mount. They actually touched, so I had to have them rotate the outside of the muff down just enough that the bolt and muff wouldn't rub.

Makes my wish I had gotten a "narrower" or round muff. But they work just fine now. Fortunately I have a mount just behind the muffs so the system is pretty free of movement.