General LSX Automobile Discussion - Glass packs vs Bullets

Hey guys, question here. Seems to me the dyomax bullets are basicly a glass pack no? So cant I buy 2, 3" summit racing glass packs and end up with the same thing for half the price? Does anyone know if the bullets sound that much different, could you even really tell? Does anyone have a cammed ls with glass packs? Thanks

I'm gonna bet a cammed LS with glass packs would be pretty raspy. LOUD of course however I have heard that turning them backwards helps with sound but I'd imagine it would restrict flow.

I used those Summit "Bullet" 12" glasspacks on my Z71 truck. The interior design is a bit different (mainly just the perforations) , but not much.

I can't say anything about how the sound will be on a ride with LT's as I have never heard the Summit glasspacks like that. I only have experience with 12" Dynomax bullets on my T/A(LT's and no cats). I did like the Summit glasspacks on my Z71, which still have stock manifolds and cats. It had a pretty deep tone to it, zero rasp (it was dumped under the bed of the truck).

If I had to guess, I would say they will sound pretty similar.

Humm, so are thinking the glass packs are different then? I have heard a butt load of bullets and I think they sound awesome. I just only remember glass packs on old cars, they were kinda hit or miss. Ether sounds good or like shit, not sure if I should chance it. Does anyone know if the bullets definitely have there own sound, or are you just paying for a name?

I used those Summit "Bullet" 12" glasspacks on my Z71 truck. The interior design is a bit different (mainly just the perforations) , but not much.

I can't say anything about how the sound will be on a ride with LT's as I have never heard the Summit glasspacks like that. I only have experience with 12" Dynomax bullets on my T/A(LT's and no cats). I did like the Summit glasspacks on my Z71, which still have stock manifolds and cats. It had a pretty deep tone to it, zero rasp (it was dumped under the bed of the truck).

If I had to guess, I would say they will sound pretty similar.

Thanks man, I definitely do not want rasp or to junk up the sound of my car!

A bullet is a mostly a name coined by Dynomax. It's still a "glass pack". Any muffler with holes or perforations where the sound flows through into loose woven fiberglass is a glass pack. I think other companies have used "bullet" to describe its shape. Mufflers without fiberglass packing are usually considered chambered mufflers. I see this confusion often.

A bullet is a mostly a name coined by Dynomax. It's still a "glass pack". Any muffler with holes or perforations where the sound flows through into loose woven fiberglass is a glass pack. I think other companies have used "bullet" to describe its shape. Mufflers without fiberglass packing are usually considered chambered mufflers. I see this confusion often.

Thanks, thats what I was questioning. But here is the thing, I have heard that people do actually like the summit glass pack... but does the dynomax have its own sound or do they sound very much like a quality glass pack?

Bullets sound much better. Glass packs belong on old street rods.

Bullets sound much better. Glass packs belong on old street rods.

Proof please? Been seeing this debate for years...

My understanding is that most traditional style Glass-Packs have a louvered core that protrudes into the flow path, and bullet mufflers have a perforated core that doesn't.
Imo, for a smoother sound and higher flow rate get a traditional style bullet muffler, but if you really want a rougher/raspier sound then get a glass-pack.

I don't know what makes the difference but I've heard a lot of cheap glasspacks on several things and I do not like them at all. My car had them when I bought it. They sound deep but kinda "fart" like with RPM with an obnoxious cackle under deceleration.

But the dynomax bullets on duals for fbodies sound good, it's like a more open header aggressive sound but with cleaned up tone and some volume control.


That being said it could just be that I've only heard Dynomax bullets on lsx engines and glasspacks on more traditional type engines, and I do not know why the difference is there but it's enough I wouldn't want to risk installing no name glasspacks on my car because then it would just be more expensive to fix. I would not be able to tolerate what I think of as the "glasspack" sound on any car/truck I own for more than 10 minutes.

If you look inside the O'reillys thrush glasspacks, they look just like the dynomax bullets, it's a perforated tube and not louvers. I think the summit/jegs glasspacks are the same, but not 100% certain. I think the old original Cherry Bomb mufflers did have the louvers though. Not a huge difference in sound in my opinion.

Im running Kooks Lt's & ORY and a summit glass pack with a turn down and it sounds really good at idle and WOT. It does have rasp on slow acceleration from about 2100rpm to 2500rpm. I was thinking about buying a Dynomax bullet and seeing if that would get rid of the rasp but if its the same as the summit glass pack there is no sense in it.

Have a decent camera to take a video? Just curious if the difference I hear is in the engine and exhaust combo more than the muffler

Have a decent camera to take a video? Just curious if the difference I hear is in the engine and exhaust combo more than the muffler

The only video I have of it is when it was on the dyno not very good quality nor what you are looking for but here it is. Im ordering a Magnaflow muffler http://www.summitracing.com/compare.aspx to replace the glass-pack in hopes that it gets rid of the rasp and drone.
http://i794.photobucket.com/albums/yy223/atrain59/th_VIDEO0009.jpg (http://s794.photobucket.com/albums/yy223/atrain59/?action=view&current=VIDEO0009.mp4)

Im running Kooks Lt's & ORY and a summit glass pack with a turn down and it sounds really good at idle and WOT. It does have rasp on slow acceleration from about 2100rpm to 2500rpm. I was thinking about buying a Dynomax bullet and seeing if that would get rid of the rasp but if its the same as the summit glass pack there is no sense in it.


The rasp is coming from the y pipe, not the muffler.