After the glass pack that was on my GTA since I bought it finally fell off, I've been running the 2.5" dynomax Super Turbo crossflow muffler that used to be on my IROC. It's too quiet and I want to replace it, so I ordered up what I need. Rather than use another crossflow muffler, I'm going to use a standard 2.5" offset in offset out muffler with a single tail pipe that's tucked up out of sight. This setup is cheap, flows better than a crossflow, and tucks out of sight nicely. I have a set of 2.5" Pypes Violator mufflers that I picked up for my truck, and the other day I tried one on the GTA. I was extremely impressed with the sound, though I didn't drive it anywhere because I didn't have a tailpipe yet. Today my thrush welded muffler came in, and tomorrow the tail pipe comes in. Once I get things installed, I'll post some video clips, though my camera mic is rather bad, so everything sounds pretty similar. But, since I found virtually no info on either of these types of mufflers, I want to post this so that others can learn about them. First the pypes. The ones I have are the MVV10 Violator mufflers. Here's a pic: I hooked this up temporarily just to start the car and rev it. If I didn't need it for the truck, it would have stayed on the car. I might replace my 3" spintech on the IROC with a 3" pypes violator. Next to a chambered exhaust, this is bar-none the best sounding muffler I've heard, and considering it was on a stock LB9, I can only imagine how it would sound on my IROC. It had a raw sound, without that tinny cheap sound that my spintech has. I can't wait to try driving the car with it to see if it stays that way under acceleration. The other muffler is a Thrush Welded muffler. I couldn't find anything online that gave me an idea of what this muffler is, but at under $30, the price was right. The part number is 17659. The muffler is very well made, and seems to be a Flowmaster clone. It looks exactly the same inside as a 2 chamber flowmaster muffler. For those who like the flowmaster tone, this will be a huge money saver. Like I said, I hope to take some video this weekend and I'll post it next week.

Quick update:

I took video of the car idling and driving by with the thrush, and video of it idling with the Pypes. I haven't taken the video of the Pypes driving by... perhaps tonight.

What really surprised me was how quiet they all were. The Thrush sounded virtually identical to the Dynomax crossflow. Even in the video you can tell it's quiet. Driving by, you hear more air noise than exhaust. I put the pypes muffler on, execting a huge increase in sound, but the increase was very subtle. Last time I had this muffler on the car (without a tailpipe) it had a very nice, relatively loud tone. With no changes other than just adding a tailpipe, it seems like it completely quieted it down. Before I go back to the Thrush, I'm going to take another video of the car without a tailpipe for the sake of comparison.

With any luck maybe I'll get the videos up tomorrow.

Unlike most people, I'm looking for a quieter muffler, both for the Camaro and the '57.

Neither of these should be quiet. It's got to be due to the rest of the exhaust, not the mufflers. The Thrush is a 2-chamber flowmaster clone, and the Pypes, well you can see right through that one!

For a good quiet muffler, it's hard to beat a Dynomax Super Turbo.

Another "quiet" alternative may be the Hooker Aero Chamber #21512 with a 22" case length (Chambered). I just swapped my Flowmaster single 3" #53033 to this one. The Hooker is nearly 5" longer in overall length. Much more quiet, nice rumble at idle, absolutely no more "tinniness" compared to the FM sound and overall just sounds more "muscle" even for a single 3". I have mp3's of before and after if someone wants to here it I can email them. This is with 2210 LT's into a mandrel bent dual 2.5" into single 3" y pipe with no cat.

get that vid up!! i'm really busting my balls trying to decide what exhaust to get for my stock LB9, it's a toss up between a chambered exhaust (powerstick), an SLP LM2, edelbrock SDT, or if this truck exhaust is good i could look into that.

I've got most of the videos I wanted to take. Like an idiot, I manged to be in picture mode and not in video mode when I thought I was getting video of the pypes muffler on the car. I didn't discover this until I had already gone back to the Thrush.

But, here's what I've got. The car is an 88 GTA with a completely stock LB9 and a T5. The exhaust consists of the stock manifolds, stock y-pipe, stock cat and stock 2 3/4" intermediate pipe. I simply changed the muffler and tailpipe. Mufflers are the ones that were used above. Tailpipe is Walker part number 43244.

Anyway, here are the videos along with my commentary:

1. Dynomax Super Turbo crossflow with dual tail pipes:
This is a good flowing, stock replacement type muffler. It flows better than the glass pack that was on the car before, and is much quieter.
http://www.iroczone.com/technical/Exhaust/dynomax.mov

2. Here's the car with the Thrush muffler installed. The tone is more distinct than the dynomax and sounds better. It's still very quiet though.
http://www.iroczone.com/technical/Exhaust/thrush.mov

3. Unfortunately, I goofed up on my pypes video, so I don't have that. BUT... I did take another one with the tailpipe removed. The difference in sound with that last piece of tailpipe is dramatic. Without the tailpipe, the pypes muffler is much louder and has a nice raw tone:
http://www.iroczone.com/technical/Ex...notailpipe.mov

Note: With the tailpipe, the pypes muffler has a nice, but still quiet tone. It's slightly louder than the Thrush muffler

4. Here are a couple videos of me driving the car. The first is the Thrush, the second is the Pypes. The third is me pulling back into the yard with the Pypes.
http://www.iroczone.com/technical/Ex...sh_driving.mov
http://www.iroczone.com/technical/Ex...es_driving.mov
http://www.iroczone.com/technical/Ex...s_driving2.mov


Overall, ALL of these systems are quiet. All you're really changing from one muffler to the next is the tone. I think you could even run a straight pipe instead of a muffler without it being too loud. I suspect that a mandrel bent 2.5" intermediate pipe would sound better than the stock crinkle-bent 2 3/4" pipe that I'm still using. If you want it loud, you need to run a 3", or at least have more motor. This dynomax muffler was originally installed on my IROC and it was significantly louder on that car.

My favorite of the three is the Pypes muffler. I am impressed with the tone from this muffler. It seems to have a nice deep rumble without any kind of tinny sound. The Thrush is a great muffler for the money. Anybody who is considering a flowmaster should buy the thrush for less than half the cost, since the thrush is a flowmaster clone. My one gripe about the thrush is that the pipe size was a bit large, so I had to really crush it with the clamp for a good seal. The Pypes mufflers offered a perfect fit. The Pypes muffler is also reversible for a different (quieter) tone, so it's like getting 2 mufflers in one. I can't wait to put the pair of these pypes mufflers on my truck!

Just for Comparison, here's the same dynomax when it was on my IROC:

http://www.iroczone.com/technical/Exhaust/dynomax1.avi
http://www.iroczone.com/technical/Exhaust/dynomax2.avi
http://www.iroczone.com/technical/Exhaust/dynomax3.avi


My IROC is a 10:1 350 with modified TPI and a mild cam (214/224 .442/.465 112lsa) and ancient 461 fuelie heads. Exhaust consists of 1 5/8" heddman shorties with a heddman y-pipe flowing into a 3" dynomax high flow cat. Intermediate pipe was the 2.5" pipe that came with the dynomax catback.

Full tailpipes to the rear bumper on the '57, still loud. With Summit fully welded, and the current CB Vortex.
I have an Aero Exhaust Turbine muffler on an '84 full size van, you can see right through that one, too. But, it is quiet, except it tends to drone under slight power. Main problem with it is they are $300/ea.!

I keep wondering about them, and Borla Pro XS. I'm willing to go to a 3" single on the Camaro.