silver84

Glasspacks.

loiq

Your car will be loud with "cherry bombs."

Check out Dave Vizard's book on building big-inch chevy small blocks. He has a diagram that shows how the exhaust "sees" each type of muffler. When you see the diagram of the "cherry bomb" you will understand why they don't flow as well. I will try to scan and post.

OK, here it is. Though the example cites muffler intallation onto open headers, it should still be self-explanatory.

cv67

30 year old technology is usually cheap. Personally I'd stay away from them unless you want compliments from toothless women and kids with three thumbs Seriously, don't. Just my .02

rocco16

Clarence, buddy....
If your mind was already made up, why ask us for our opinions?
Just as you are repeating what you heard about cherry bombs, I'm repeating what I've heard.
No one is looking for an argument, we're just looking for information.
Put the damn things on your car if you want. I put them on my Chevy truck thirty years ago and was not impressed (all I got out of that deal was an "exessive noise" ticket)
Your results may vary.....
Larry

ZumZum

I don't see how this is showing that glasspacks flow less then turbo mufflers. It seems to me that all this is showing is how muffler installation immediately after the header collectors can act as an extension of the collector. Lengthening or shortening the collectors can effect engine tuning. Installing the glasspacks immediately after the header collector makes the engine perform as if you actually have a super long collector length IMHO.

ClarenceT

Because i wanted to know what they sounded like on a vette; my mind wasn't really made up - im all ears for in cab resonance and dB with a (comparatively) big motor like a 350. As far as flow and all that, I've been there and it's better then OEM from what i've seen, and read (save for a few comments here )

I don't want a car that's too loud, but I could use a little more exhaust flow - thought this was a good compromise. As I said, I guess I'll go try it - I won't be out that much money, and I'll make a few videos along the way for everyone to draw from sice opinions are so mixed..

Keep in mind, I hate loud cars that are slow (like a stock Stanger GT with 40 series or something) - and I see my vette as pretty slow haha, so yeah I definitely don't want to make it sound like I got something.. Stealth is my thing, but I do like a deep rumble at idle just to cover up the whine of all those damn accesseries!

ClarenceT

Ok, first of all, what's "loud" - can't have a conversation at a stoplight in neutral loud? Shed more light on this please.

Secondly, your diagram doesn't have anything to do with backpressure, which is what we were discussing, but rather velocity of escaping exhaust gasses, which needs to be high obviously - this is achieved by keeping the primary collector of a proper diameter - too small is restrictive, and too big causes them to cool off and lose that velocity (hotter gasses are less dense, and flow faster). In case, a glasspack would become an extension of the collector and screw things up.

In my case, keeping the stock manifolds, y-pipe, cats, and cat-back piping this matters much, much less. Of course a straight, hole free piece of pipe (muffler elim) would be best performance wise, however that would definitely be too loud for my tastes. I need SOME form of silencing...

JrRifleCoach

I once did a side-by-side dyno compairison of glaspacks and straight pipes. Straight pipes won! And sounded better too!

cv67

If you are looking for stealth, glasspacks may not be for you. I understand dynomax makes a quiet muffler and adds decent torque. Might want to check around

TA

I don't think "cherry bombs" are all that different from the targa-style mufflers that many here run.

silver84

I own an old 'vette, with a 327,
headers and glasspacks [normal, not jumbo Magnaflows]
Great sound, and pulseing

.
Glasspacks

Corvette Kid

I came of age in the late 60s-early 70s and am ashamed now to say that I was part of the counter-culture in which that term for law enforcement was coined. I've now lived long enough to see that the stupidity of that culture, although still embraced by the liberal elites, was nothing but a bit of idealism gone wildly astray and sadly is still is having a detrimental effect on our society in my opinion. I, like most of us, am sometimes guilty of lumping a group of people together in a negative context or stereotype and it's something we all must work on to make the world a better place for all. Obviously, as I'm sure you know, they are human like all of us and some are going to be jerks. But overall, they do a difficult job well without enough public support at times and fail, too often, to get the benefit of the doubt from the sensationalist media, too. I respect them greatly and thank them for their service. Sorry for getting off topic but I wanted to address and accept your apology and explain why I hate hearing that term used. Good luck with your muffler selection and your Vette and I'll see you on the forum, my young friend.

Nathan Plemons

Hey guys I think we're missing a VERY important point here. Most glasspack mufflers are actually pretty freakin quiet. When you hear a car with glasspacks that its just extremely loud and has that popping and crackling sound to it that is just so redneck it's for a reason. The reason? THEY INTENTIONALLY INSTALLED THE MUFFLER BAKCWARDS! This causes it to flow for ****, make a ton of noise, and generally sound like crap. We like to call them AssPack mufflers.

A properly installed glasspack is almost dead quiet, if you don't believe me I can take some sound clips of my dad's F-150. It has a really neat sound when you first start it up, but otherwise it's dead quiet at idle and cruise. I wouldn't know what it sounds like when you really fire down on it because it's an inline 6, it doesn't fire down very well.

RED-85-Z51

Shut up, you asked a question, people gave responses, and you disagree with some of these responses.

You had every intention of getting the cherry bombs from the beggining, so why did you even ask for our opinion?

I got no beef with joking around about leos and the like, but dont go call them pigs, thats just wrong. Also, post like the one ive quoted here in which you backtrack and insert foot in mouth, make you look stupid.

loiq

The diagram was posted as an example of how exhaust gases "see" the different mufflers they travel through. If you don't like the info disregard it. Simple.

Nathan Plemons

I think what he may be getting at is that muffler placement in the exhaust stream has a big effect. That may be perfectly valid for mufflers placed right off the header, but we're not talking about mufflers placed right off the header. Stock manifolds, cats, extra pipe, etc all changes the scenario.

It's perfectly good information, it just might not apply 100% in this situation. Then again it might, I'm not an expert on exhaust flow either. We just have to remember to be careful when trying to apply data to a situation. Kinda apples to oranages if ya know what I mean.

Bruthish

I have the KBD Targas and they look very similar to Glass packs, there are just 4 of them coming out the rear. If they are the same principle, I will have to sya that the sound is pretty good and they are not too loud until you step on it. Its pretty quite actually and no resonance in the car at all.....


Good Luck

comp

look in them only 2" threw there m
new one's may be 2 1/4"

ClarenceT

Nathan, thanks.. I didn't know that you could install them backwards to achieve a different sound, but always knew that they did a fair job of silencing (if installed following the giant arrow stamped on each one of them ) leaving only subdued rumbles behind.. From what I can tell, people that have had first hand experience with them like them, but people that judge through hear-say tend to be negative (using the old "if it was so good everyone would use them" fallacy, etc) Again, this only makes me want them more just in case it works out great - a good deal of people could save a good deal of money (i mean, someone had to find out that the airfoil was too good to be true, right! )

Corvette Kid NC - Again, I have nothing against the police department (meybe an occasional butthead with a power trip here and there, but as I said that happens in every field) and too respect what they do. Keeping the social order is a job that has to be filled, believe me, I'm not an anarchist. A term like "pigs" is only as evil as the meaning behind it, and I assure you I mean no more harm when i say it then when i make blond jokes Blonds are just as respectable as any other hair color, but I don't think I should have to clear that up if I ever make such a comment, know what I mean? Sorry if you took that the wrong way.

Red85 - who pissed in your wheaties? Get a sense of humor, it'll be hard living in this world without one. Also learn to read - I said I was looking on opinions about the sound, since I've never ran these on a motor as large a 5.7 (This is almost verbatim from a few posts above). I guess I was lying, you're right. I'm just here to troll and tell everyone to shut up.

information junkie

now that is a good point. also remember that there are diffrent styles of glasspacks. most "coffe can" mufflers are a glasspack with a large body. if you install a glasspack right and use one that is long enough it will be quiet. if it is short it will be loud.
i have driven many cars with stock style mufflers and then driven them after installing glasspacks(worked at a muffler shop) and feel that a supperturbo muffler is a better option for sound and power. but the sound is still a matter of opinion, everyone likes diffrent sounds.