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Technical Another glass pack question about thrush glass packs

Discussion in 'The Hokey Ass Message Board' started by chasey32, Feb 25, 2017.

  1. chasey32
    Joined: Dec 6, 2016
    Posts: 28

    chasey32

    Has anyone actually had any problems with Thrush 26" case glass packs?? I'm just looking for a good choice for my 62 which gets driven roughly 150 miles a week. What I do know it the life expectancy of a glass pack is about two years or so on a daily driver. so basically I'm looking at thrush or smithys that are 30" case but are smithys really worth double the price? And with that said they will be put as far back in the system to keep the glass from burning.also they will be run all the way to the bumper and maybe a inch or two past it so that the sounds follows the car instead of resonates under it so there should not be any drone I'm really trying to get a deep glass pack rumble without all the unpleasant side effects that go with type of exhaust. What do you guys think?? Oh and it's a 62 Mercury with a small block


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  2. jnaki
    Joined: Jan 1, 2015
    Posts: 9,372

    jnaki

    Hey Chasey32,
    When we put on 30 inch tubular straight through mufflers on our 58 Impala, without the tail pipes going out to the rear, our motor sounded like a pure bred drag racer. (348/280hp+) When we drove it around just to see what it was like, after a while, it was too loud. But, at the local drive in restaurant where everyone would be, there was this alley behind the last row of cars. That alley ran between several 2 story apartment buildings. It was "drag pipe central" as it made such a cool sound accelerating down that alley. On the street, it just resonated too much in the cab without the long rear extensions.

    So, if I had a choice, I would get the 30 inch over the 26. With the tail pipes going out the back, you will not get the rat-tat-tat sounds, or, the popping sounds associated with those tubular mufflers. It will be nicer for the occupants inside of your car with some sounds, but not the ear shattering ones. YRMV

    Jnaki
    With just the 26/30" mufflers and no tail pipes, you can cruise at a certain rpm to make it a little less noisy. We had to keep it at this newly found rpm anytime we came up next to a police car while cruising around. But, in the end, I had to get the rest of the stock tail pipes put back on the set up. Did the straight through mufflers help increase the horsepower in the motor? It sure sounded/felt like it, but unless you have free flowing headers, any restrictions will make a lesser amount of horsepower, but more than stock.
     
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  3. flatheadpete
    Joined: Oct 29, 2003
    Posts: 10,484

    flatheadpete
    Member
    from Burton, MI

    I just put new exhaust on my '50 Ford. I used Powerstick mufflers (made in Michigan!), 2 1/4" tubing and stainless headers. Ran duals down the passenger side all the way back to the bumper. These mufflers are kinda loud upon acceleration but really settle into a mellow rumble while cruising. And, the mufflers are made of perforated steel so there's no packing to burn out.
    BTW...302/C4 combo.

    http://classicchambered.com/classic/products.html
     
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  4. blazedogs
    Joined: Sep 22, 2014
    Posts: 535

    blazedogs
    Member

    Bought 2 for the model A I thought they were poor quality Welds were bad etc Also caution - Most Thrush are directional Be sure you look for the arrow
     

  5. Bugguts
    Joined: Aug 13, 2011
    Posts: 889

    Bugguts
    Member

    Just my opinion, but in the big scheme of cost vs time, a little more money for a nicer muffler will save big money down the road as they will hopefully last longer. All the Thrush mufflers I bought when younger was because of cost, and they all rotted out early and ended up costing me more in replacent.
     
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  6. sunbeam
    Joined: Oct 22, 2010
    Posts: 6,219

    sunbeam
    Member

    I always liked the sound of walker glass packs.
     
  7. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,910

    dirty old man
    Member Emeritus

    Mitchell made some great glasspacks in 30" case length, but I don't know mif thet are still around. Porter is a good muffler too, and the compsny is small enough to be flexiblein making you a somewhat deep tone but not blaring loud. Give them a call.
     
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  8. chasey32
    Joined: Dec 6, 2016
    Posts: 28

    chasey32

    Also it's going to be a traditional custom so I'm might do bellflowers I'm just so picky I can't decide


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  9. upspirate
    Joined: Apr 15, 2012
    Posts: 2,299

    upspirate
    Member

    I used Thrush on my second car back in 1970.
    I couldn't afford the good blue or red brand ones. (whatever they were,Walker,Cherry Bomb I think they were)
    The Thrush had a shitty sound compared to the others and was cheaply made.
     
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  10. Wyld Deuce
    Joined: Oct 17, 2005
    Posts: 104

    Wyld Deuce
    Member
    from ...

    The farther away you put the muffler from the header, the more polite the rumble.
    Where the 30 inch model goes, I had one on my shoebox's flathead.
    It was located just in front of the axle, polite sound but a lot obnoxious popping on deceleration.
    I have 12 inchers just in front of the axle on my Mustang, polite sound...no obnoxious popping on deceleration.
     
  11. chasey32
    Joined: Dec 6, 2016
    Posts: 28

    chasey32

    This is good to know I was going to do a H pipe to try to take out the that pop on deccel and going down hills in town


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  12. chasey32
    Joined: Dec 6, 2016
    Posts: 28

    chasey32

    Side note I have 20" right now that turn out in front of the rear tires and I get a lot of glass pack sound but the drone I hate..!! So if I read you guys right if I run another set of 20-26" and just run them all the way back it should be pretty mellow?? I do want steelpacks just for the fact I think they will last a little longer then fiberglass,, so I'm thinking porters, or Brockman's


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  13. KoolKat-57
    Joined: Feb 22, 2010
    Posts: 3,076

    KoolKat-57
    Member
    from Dublin, OH

    Back in the day, Thrush were cheap and sounded cheap almost like a machine gun firing.
    They would rust out quickly which was a real pain in the dead of winter and you had to replace them on your back on a cold driveway or garage floor!
    Brockman, Porters, or even Cherry Bombs are a much better choice.
    KK
     
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  14. flatheadpete
    Joined: Oct 29, 2003
    Posts: 10,484

    flatheadpete
    Member
    from Burton, MI

    I ran Thrush welded mufflers on my daily and they wore (rusted) out within a couple years. Spend good $$ on a good product. Value actually has meaning...
     
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  15. @flatheadpete do you have a video of how your shoebox sounds? Thinking about doing that setup on mine.
     
  16. upspirate
    Joined: Apr 15, 2012
    Posts: 2,299

    upspirate
    Member

    Why not have some pipes out the rear made up and hooked up to what you have now and see how it sounds? Have them made so you can use them if you decide you don't like the sound and change mufflers later
     
  17. chasey32
    Joined: Dec 6, 2016
    Posts: 28

    chasey32

    The set up now is probably the worst exhaust I've ever seen.. the guys before me did it but there is literally 4 different size pipes between the original manifolds back to the rear tires. Which probably adds to the awful sound but I want to have it done from the manifolds back with new pipe and be done with it then move on to other aspects of the car


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  18. Yes, have it done from the manifolds back, then the mufflers will be the least of your expense. Go for some good ones.

    The Smithys with my flathead sound great, but I have to admit the exhaust is not done yet (they end right under the front seat).
     
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  19. I have Cherry Bomb (Summit house brand) glass packs on my '59 Ford with exhaust out to the bumper. Quite LOUD and hard to talk inside the car. Raspy as hell and I soft-pedal it when I see a cop, so far no issues.

    I need to change them and like the Smithys made by Patriot, which are a steel pack and it will be an easy fix. Are the steel packs generally quieter than glass packs? I will look at the Thrush ones the OP mentioned.
     
  20. chasey32
    Joined: Dec 6, 2016
    Posts: 28

    chasey32

    I've never tried steel so I can't speak for them but I have read that fiberglass is supposed to be more mellow and of course the longer the quieter so I'm going to try smithys because everyone complains there too quiet, but that's what I wanted in the first place


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  21. The Smithys I'm looking at are 26" overall and an easy swap for me. I don't mind a little loud, mine is a lot of loud. My exhaust has turndowns under the bumper.
    916-004.JPG
     
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  22. BamaMav
    Joined: Jun 19, 2011
    Posts: 6,744

    BamaMav
    Member
    from Berry, AL

    Last glasspacks I bought were the Red Hots from Flow Tech. They were the cheapest I found at Summit, 24" IIRC, 2.25" tube. With them mounted right in front of the rear axle and 45* down dumps, they droned like hell at 55-60 mph. Added over the axle pipes with a rear exit, the drone went away. They were loud when you mashed on it, but mellow just cruising around.

    Current car has some kind of generic Flowmaster looking muffs on it with exits at the rear bumper. With the Chevy engine, they had a bit of drone at highway speeds, but not too bad. Going to see how they sound with the small block Ford engine, if I don't like them I'll be looking into something else myself.
     
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  23. chasey32
    Joined: Dec 6, 2016
    Posts: 28

    chasey32

    First off thanks everyone for the ideas and thoughts!! My plan is from the manifolds I'm putting in a H-pipe then 30" case smithys then over the axles into bellflowers should be nice a mellow when cruising then have a nice bark when it gets angry!! I'll update again later this summer when it's al done!! Again thanks to everyone!!


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  24. dirty old man
    Joined: Feb 2, 2008
    Posts: 8,910

    dirty old man
    Member Emeritus

    Since we're all subscribed to this thread since we posted on it, let us know on this thread, please.
     
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  25. A few general comments on exhaust notes. Fiberglass attenuates high frequencies a lot better than steel so yeah, they'll sound more mellow/less harsh. Along with length, diameter also makes a difference. The thicker the glass the better it will work. Smaller pipes attenuate lower frequencies more than larger pipes. Long pipe lengths can create drone so moving the mufflers all the way to the back of the car isn't always a great choice. Every car is different, so what works on one may not work on another. Typically you want some sort of tailpipe though, short and/or large tailpipes can cause issues, like droning off idle. Long expanses of pipe can also create a "rap" sound, School buses are often used as an example.

    Some mufflers have the louvers punched into the flow but there is no good reason to do that. They don't "scoop up" the sound. Sound travels in all directions and will find it's way out perfs and outward louvers with no issues. People tend to confuse the exhaust flow with the sound pulses, they are not the same. The proof is easy - exhaust flow does not travel at the speed of sound. Once the flow hits about 40% (? it's been a while since I screwed with this stuff) of the speed of sound you start running into issues with flow noise, the exhaust sounds like a jet.
     
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  26. My glass packs are the Summit Flo Techs, Cherry Bomb knock-offs.
     
  27. clo
    Joined: Mar 4, 2011
    Posts: 34

    clo
    Member

    Brockman glass packs is the way to go. Made from heavy gauge. Steel packs are louder. I have the shortest Brockman steel packs. I'm running a flathead. There not to loud with 1 3/4 piping all the way back.
     
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