glass packs?
Posting Guru
Joined: Nov 2005
Posts: 1,113
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From: the side of a mountain
i have them runnin on my 390 with 2" duals and it is annoyin becuase of the little pipes it gived it a high pitch sound but it sounds cool gettin it to about 4500 and lettin off and hearin it cackle. and with them small pipes it cackles like nobodys business. now if i had 2.5" pipes i think it would be a bit different and less of a pop and more of a rumble but when i get a new exhaust im just going to put single chamber mufflers on it and cut outs at the headers.
Senior User
Joined: Aug 2004
Posts: 382
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I have 2 18" glasspacks on my 390 with headers and it sounds great. I am thinking about turning them around to make it a little louder though. Some of the new trucks with their flows are just as loud as mine, I can't have that. 
Fleet Mechanic
Joined: May 2004
Posts: 1,436
Likes: 0
From: Montana
Originally Posted by eedvark
I dont know why they call your posted muffler a "turbo" muffler but it is NOT what I am refering to.
As most of you know the Chevrolet Corvair (sorry for the fowl language but bear with me) was a compact rear engine economy car from the 60s.This car featured a flat or horizontally opposed 6 cylinder engine mounted at the extreme rear of the car.Because of its location this engine required the muffler/mufflers to be mounted extremely close to the engine.The high heat transfered to the short exhaust would burn up the fiberglass packing in a conventional muffler.Also if unburned gasoline built up in the muffler/s the engine heat could cause them to explode.The optional Turbo engine Corvairs made the heat problem even worse.
Engineers had to design a new muffler with low restriction and high heat resistance.The 3 chambered design that resulted was the "Turbo" muffler.This muffler soon became very popular with hot rodders because of its low back pressure. The after market today has several copies of this GM designed muffler. It has been one of the most efficient designs for over 40 years.The link posted shows an internal view of a true "turbo" muffler.
http://www.a-1performance.com/super_turbo/
Sorry to be long winded but I guess I got my horn stuck again.
As most of you know the Chevrolet Corvair (sorry for the fowl language but bear with me) was a compact rear engine economy car from the 60s.This car featured a flat or horizontally opposed 6 cylinder engine mounted at the extreme rear of the car.Because of its location this engine required the muffler/mufflers to be mounted extremely close to the engine.The high heat transfered to the short exhaust would burn up the fiberglass packing in a conventional muffler.Also if unburned gasoline built up in the muffler/s the engine heat could cause them to explode.The optional Turbo engine Corvairs made the heat problem even worse.
Engineers had to design a new muffler with low restriction and high heat resistance.The 3 chambered design that resulted was the "Turbo" muffler.This muffler soon became very popular with hot rodders because of its low back pressure. The after market today has several copies of this GM designed muffler. It has been one of the most efficient designs for over 40 years.The link posted shows an internal view of a true "turbo" muffler.
http://www.a-1performance.com/super_turbo/
Sorry to be long winded but I guess I got my horn stuck again.
FIBERGLASS MATTING delivers a mellow, true performance sound
Elder User
Joined: Feb 2005
Posts: 669
Likes: 1
I've got glass packs on my truck as well. I've got the 36" cherry bombs....I used to run those when I was a teenager....I was shocked to find that they still made those things...had to have a set...and I love the sound of em! 
Fleet Mechanic
Joined: May 2004
Posts: 1,436
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From: Montana
Originally Posted by charles jones
As a kid we used to get 12in. glass pacs and have em welded on backwards so those little scoops didnt grab any sound and then drive em home 20 miles at 75mph and run the water hose up the tail pipe and get rid of what ever was in em.
Senior User
Joined: Jan 2006
Posts: 195
Likes: 0
From: upstate N Y
My Grandmother use to say "well the cat had kittens in the oven ,but we didn't call them muffins." Guess I understand what she meant now.The turbo muffler design refers to the path through the muffler not the packing or lack of packing.Anyway I like glasspacks ,not on race cars but I like glasspacks.I cant help what the exhaust companys call thier products.If my 65 Falcon wagon with a 200 and a header ever gets done it WILL have a glass pack nothing louder than a strait 6 with a glasspack.
Senior User
Joined: Oct 2003
Posts: 358
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From: Joyce, WA
In a big old truck ya gotta go with glasspacks! Small children run and dogs hide when I come thru town. 4000rpm and let off the gas. The bark will almost set off car alarms!! Yea, loud and gas pedal are attached in my head. I figure that is what hearing aids will be for in the not to distant future for me.
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Logistics Pro
Joined: Jun 2004
Posts: 4,763
Likes: 3,378
From: South Central Utah
I have glass packs on both my trucks. The 79 F260 has fenderwell headers and the pipes exit in front of the back tires and it is too loud for me when getting on it. The 72 both pipes exit in front of the R/R tire and it sounds great. With the windows up I barley hear it.
I do like the sound of the '79 when just driving around and I really like the sound of the '72.
I do like the sound of the '79 when just driving around and I really like the sound of the '72.
Junior User
Joined: Oct 2004
Posts: 88
Likes: 0
From: hollister, ca
yeah i was running cherry bombs for a while, but then i got single chamber flows, i liked those fine untill i got my duel 5in stacks coming up through the bed behind the cab... those flows are too harsh, im going back to the glass pack ... still loud and deep but not so harsh
Elder User
Joined: Mar 2005
Posts: 709
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From: Mesquite, Texas
I had 59 F350 292 I think with a flat bed and headache rack for haulin hay as a kid and ran the exhaust up two drill stem stacks 4ft. above the cab right behind it between the rack and cab. Straight exhaust no mufflers. My dad could hear me coming home at midnight 2 miles away when I let off the gas to make the turn off the highway to our fm road. He always said I would catch a load of hay on fire with that setup but I never did. Those sure seemed like good ole days. Pull in the service station and fill it up with oil and check the gas, didnt burn any but leaked like a siv. Texas Star re-refined .13 a quart if memory serves me correctly. Never had to change it cause it was always new and clean. lol
New User
Joined: Dec 2005
Posts: 15
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i know what you mean when i lay on the gas coimg out of town my parents can hear me its a flatbed i want to stack it but i just have its piped and glasspacked right out the back its nick name is the tank because i can pull anything with it bust through anything and if you saw it you would know why Oh i haul scrap iron with a 30 ft flatbed and i can still pass anything but a gas station lol
Originally Posted by charles jones
I had 59 F350 292 I think with a flat bed and headache rack for haulin hay as a kid and ran the exhaust up two drill stem stacks 4ft. above the cab right behind it between the rack and cab. Straight exhaust no mufflers. My dad could hear me coming home at midnight 2 miles away when I let off the gas to make the turn off the highway to our fm road. He always said I would catch a load of hay on fire with that setup but I never did. Those sure seemed like good ole days. Pull in the service station and fill it up with oil and check the gas, didnt burn any but leaked like a siv. Texas Star re-refined .13 a quart if memory serves me correctly. Never had to change it cause it was always new and clean. lol
