I've got the sound quality, it's just gonna be too noisy. I bet the magnaflow bullets with their stainless steel mesh will be my best bet for sound reduction. That's unless anyone has a better idea. My goal is to tone down the exhaust, not kill power and hopefully retain MOST of the GMMG sound.

 

You only have 1 muffler. Also, how big is it ? The longer in length, the more sound reduction will take place. Also, he will be going through the i-pipe muffler as well as the gmmg mufflers. IMO I think any other muffler is going to distort the sound. That is why I keep preaching the powerstick.

 

Magnaflow bullets are a form of glass pack (I think they actually use a metal mesh weave similar to Borla XR-1's) but I suspect they will alter the sound as well as lower the DB level.

I do thing however that it would still sound pretty darn good

 

I have the 16"/21" version in my I-pipe. Yes, it's only 1 muffler and not the longest they make, but I seriously doubt the 20" model would make THAT much of a difference. It would probably make the sound quality even better, but doubt the volume will go down a lot. Maybe Powerstick will see this thread and comment. I recall reading a post of his stating that the longer mufflers increase sound quality, but it didnt specifically mention reduced volume.

Sure, 3 chambered mufflers would logically be quieter than 2, but I just dont see a Powerstick lowering the volume level significanly. (based on what I've witnessed on my car and a buddy's car who also has a Powerstick in his I-pipe) The GMMG is not exactly quiet to begin with and he's gonna have H/C/LTs on top of it so he needs a muffler with some sound deadening capabilities since he's looking for lower volume.

Redneck, I have no idea how it would sound w/your exhaust, but the mufflers used for Borlamouth & Magnamouth exhausts would probably be your best bet sound-wise. Personally I think they both sound great, but dont know how they would compliment that "chambered" sound. I just wish I had H/C/LTs too so I can have the same problem.

 

I'll probably give the magnaflow a shot, and post a soundclip to see what you guys think.

 

last time i heard and saw on this board(late last year) that spiral flows flow damn good....try searching for it...thats all i can tell ya unless someone who has it says something bout it.

 

I have had GMMG with Kooks headers and ORY. I hated the rasp. i put a dynomax bullet in it and it took about 85% of the rasp out but was still damn loud.

I sold it for something deeper and got a Mufflex system. The Mufflex wasn't what I wanted to I bought GMMG AGAIN and installed the Loudmouth II muffler from SLP in the I-pipe. This took ALL of the drone away as well as the rasp. Take it from someone who has been around the block and done things quite a few different ways...and paid for it. LoL

 

I did, and cam up with reports of dyno's showing big losses. I've heard the 3" spiral flows neck down to like 1.5" inside. I know, like everything else you have to take things on the internet with a grain of salt, but I just came across too many bad reports.

 

If you guys want to quiet things down without hurting flow, you need to keep the "main" transverse muffler at the rear, & add a straight-through something in the intermediate - something non-restrictive. The resonator in the intermediate should have soft packing like fiberglass (not steel wool), & be as long as will fit. My Powersticks will reduce noise & resonance, but not as well as something like a Dynomax Ultra Flo 17267 or 17299. Those are 6" diameter bodies, so I don't know if they'll fit properly under the vehicle. The problem with the exhaust routing on these cars is they call for a single in, dual out muffler, & none of those designs flow very well, plus you get an uneven sound out of each tail pipe because one of the exits will be more primary flow than the other. It's just a crappy design - all the transverse mufflers are a problem to an extent. Like running dual exhaust through a transverse muffler on the old Shelby Mustangs, & first & second generation Camaros & Firebirds - a single oval muffler with 2 inlets & 2 outlets. They all flowed like crap. Running a Dynomax Bullet in the intermediate pipe is only going to help cut about 2-3 dBA's. Those are nothing more than glasspacks with a smooth perforated, non-reducing core. They have very little body cavity area, so a very thin layer of CRF fiberglass packing which means noise absorption will be minimal. If you run nothing but pipe in the intermediate pipe area, & just a muffler at the rear, a "quiet" muffler back there will be very restrictive - that's why it will be quiet. Best combo is to run a long "resonator" in the 3" int. pipe area, & as good a flowing muffler you can find at the rear.

 

We'll I got the new heads/cam and longtubes on today. I really thought the car would be louder after the longtubes. It still is louder than I'd like, but not awhole lot louder. I still think the Magnaflow bullet in the I-pipe will be the ticket. I'll order one pretty soon and give it a shot.

 

I see you got the Longtubes in bro! bad ***!

 

Now I wonder why I didn't do this sooner! Shorty headers are for chicks lol! And for the record....pacesetters do slip right in, and the Bosch rear vette O2's work great!

 

Bringin' the thread up from the dead. I got pulled over weekend before last, because the officer said my car had a good rumble to it. He made me pop my hood, saw the longtubes and threatened to impound my car and send me to the smog ref. He ended up giving me a warning, but nevertheless made me think about making my car more quiet once again. On a rash decision, I had a dynomax bullet welded into my I pipe hoping this would help SOME in keeping me under their "radar." It did make the car a LITTLE more quiet, and took out some rasp. Long story short, the car is still loud enough to get me into trouble. I feel like one last attempt(3" magnaflow bullet) to quiet this GMMG down, before I bail my beloved catback lol. I heard a car at the track the other day with longtubes, true duals and the 3" magnaflows and was suprised at how quiet it was. Do you guys think I should give the magnaflow bullet a try before ditching the GMMG? Should I write it off as a lost cause and just trade it for a dual dual or hooker catback?

 

I think you should sell it and get what you said. A spiral flow in the I-pipe *might* quiet it down some more, but then you might run into flow problems.

I can't believe it's still too loud with cats!

 

Yeah me neither. Right after I had the dynomax bullet put on, my buddy called me from a gas station, about a 1/4 mi. away, and said he could still here me. I wasn't driving it hard either lol! The noise doesn't bother me, but is going to get me into trouble around here.

 

Just try the damn magnaflow already

 

Finally made a video clip of the GMMG. This is with a dynomax bullet welded into the I-pipe. I like the sound alot better with the bullet. It made it a little more quiet cruizing around, but is still pretty loud at WOT....



http://sd.ootoot.com/Content/whistles/jeff.wmv

 

I was curious about putting the Borla intercooled tips onto a GMMG since it mellows out the exhaust tone... not sure if I want to spend $80 on some tips though ... I don't think I want it quieter, but I want a nice looking tip :o