Write-Up: Installing Glasspack Mufflers

Smaller 2.5" exhaust = less 90º V-6 sound
Larger 3.0" exhaust = more 90º V-6 sound

Imo,the less you can hear from a 90º V-6, the better it sounds. Beyond doing a cam, there isn't much you can do to enhance the sound like you can a V-8, because a V-8 actually sounds good. 3800s just don't sound good.

Thrush part numbers

24200: 2" ID pipe, 25" overall length
24201: 2.25" ID pipe, 25" overall length (ones I used in the video)
24214: 2.5" ID pipe, 28" overall length

Thanks for the P/N's.
I might try a pair with stock exhaust to see if I like the sound. Cheap enough to experiment.
As long as there's no droning in the cabin.

I have a glasspack on mine, but it is doing duty as my resonator for the 40 series Flowmasters in place of my stock mufflers. Sounds absoultely wonderful at idle - like a LS1 i swear. But so-so when accelerating and cruising down the highway. Glasspacks are good, but do straight 3'' pipes with them out back, and your car will sound like an Evinrude moat motor running out of the water.

I was thinking about replacing my resantor with a glasspack also but I have magnaflow mufflers u think it will sound good? Also witch glasspack did you use?

I wish i knew who made the glasspack - I willtry to find that out for you. You will like it i know... I was torn between flowmaster and magnaflow and would like to hear your car asap. Go for the glasspack for the resonator.

Yeah man I will probley try to do it this weekend. If u could find out who makes it like u said that would be cool.

Well, IMHO it sounds excellent. Nice value, tough to beat.

btw you can get glasspacks dirt cheap on ebay as well. The ones I welded on with the 3" system were Hooker 2.5" glasspacks which had a baffle design that actually had little scoops. Those were an ebay purchase and I don't remember the exact price but I can tell you that they were cheap enough for me to not feel bad about cutting them off and throwing them away 20 minutes after installing them. As I said before, they ended up being too loud for the new exhaust.
They were something like $20 each though.

The paint was better on the Thrush product but other than that, a glasspack is a glasspack. The dimensions were about the same too. I cannot accurately say if the scoop-style baffle offered in the Hooker product works better than the conventional baffle used in the Thrush because obviously a lot of other factors were changed.

I was told by my exhuast guy the glasspacks with the metal scoops act like a straight peice of pipe after about 2000rpms. Has anyone else herd of this?

1wickedninja wrote:

I was told by my exhuast guy the glasspacks with the metal scoops act like a straight peice of pipe after about 2000rpms. Has anyone else herd of this?

That is the theory of most any glasspack. I imagine the scoops are supposed to absorb sound in the lower velocities (lower rpms) more effectively than the conventional pore-style baffle.

do you think that I should replace my resonator with one or just get it removed?

what do u think will sound the best with my magnaflow mufflers?

The main reason I don't like glasspacks is that their 'muffling' is done by fiberglass, which gets packed down over time and is guaranteed to fail. Resonators will probably fail someday, but at least they have steel baffles inside.

deekster_caddy wrote:

The main reason I don't like glasspacks is that their 'muffling' is done by fiberglass, which gets packed down over time and is guaranteed to fail. Resonators will probably fail someday, but at least they have steel baffles inside.

I think that would be just as true with any muffler that uses fiberglass or even anything similar to it. Turbo and superturbo mufflers use fiberglass to, I think.

1wickedninja wrote:

what do u think will sound the best with my magnaflow mufflers?

I don't know magnaflows too well but if they are all something like the ones I sell at work, they aught to be louder than a superturbo which would probably be too loud on my setup. If you're doing a full exhaust, I'd probably use a resonator with those. The one's we have - you can just about see through them. It just has sort of an S-curve through the muffler. I'd consider it about half way between a resonator and a suprturbo design.
Again that's based off of the ones that I sell at work so I don't really know if they normally have a different design.

my magnaflows are the same way u can see right though them they just have that s curve mainly because there a offset offset desigen.

i jus bought a pair of thrush glasspacks good backpressure great sound tell me what you think heres pix

from what I can tell it looks good... have you got a pic with both the glass-packs on from the back? I'd also be interested as to if its raspy at all when reving or at WOT....

damn that looks familiar!
What size?

lmao they should look familiar ........size is 2 n a quarter but they arnt like that now lol i didnt like the way they looked thats your style so i switched it up gonna post the new way lol

no raspyness ....solid deep sound, crackles a lil bit tho

sounds good

....Mexican lowrider style bout to add some flamethrowers lol

how does it sound when accelerating and what about at cruise speed (65-75 mph)?

Albertj