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Technical Muffler advice

Discussion in 'The Hokey Ass Message Board' started by Willywash, Oct 29, 2021.

  1. Willywash
    Joined: Sep 18, 2019
    Posts: 83


    Those that have a Model A hot rod, with SBC engine. What mufflers are you running? Last project was a 41 GMC truck and I had 40 series Flow Master. Truck was too loud to travel long distances. I never even put in a radio. I'm looking forward for wife and I to travel to shows and go on vacations in my 31 A. Plan on insulating floor and installing carpet. I like a aggressive sound outside of car, but would like to carry on conversation and hear radio. My crate engine has a nice sound with moderate cam. Would a Delta 40 still be too loud inside of car? Or should I consider the 50 series? I've listened to all of the test, but would really like an opinion from someone with the same car and engine.
  2. NJ Don
    Joined: Dec 25, 2019
    Posts: 110

    NJ Don

    I had Borla straight thru glass packs on my Deuce and they were pretty loud and rattled on deceleration. I switched to Flowmaster 50 series Delta Flows and like the tone much better, not as loud but a nice throaty tone. One thing is they are HEAVY! I bought the plain steel and they are made out of about 1/16" steel so if you go with them make sure your mounts are up to the weight. I wear earplugs so my wife and I don't talk ... heh heh.
    lothiandon1940 likes this.
  3. hepme
    Joined: Feb 1, 2021
    Posts: 166


    conversation, radio, long distances, insulation??
    yet, mufflers that are "aggressive" and quiet, i assume.
    I can't wait to hear which ones are recommended.
  4. Dirk35
    Joined: Mar 8, 2001
    Posts: 2,056


    Fabulous50's likes this.

  5. .........That's the craziest thing I ever heard of, but I love it!:D
    Elcohaulic, jim snow and Joe Blow like this.
  6. oldsman41
    Joined: Jun 25, 2010
    Posts: 1,556


    Being the a is quite small, I lnsulated all of mine and put normal mufflers on then ran exhaust to the rear bumper. Nice and quiet we can listen to radio talk without yelling and actually listen to the motor.I do use 2.5 inch pipe. One of my friends has the 50 series on his roadster they aren’t real bad
    samurai mike likes this.
  7. Blues4U
    Joined: Oct 1, 2015
    Posts: 6,483

    from So Cal

    Please, stay away from Flowmaster, or other brand, chambered mufflers. Those are for modern Camaros and Chargers, NOT for a classic car, and definitely NOT for a hot rod. From your description of what you want I would advise turbo mufflers. There are lot's of brands out there and people will have their favorites, but they all should sound similar, like a turbo muffler. They flow well, will let the engine breathe, with a slightly louder volume than a stock 80's sedan, with a low frequency rumble that sounds excellent.

    You really have only 2 choices for a proper hot rod exhaust note, well OK 3, some kind of glass/steel wool packed muffler, or turbo mufflers. The 3rd option would be unmuffled; or baffled lakes headers, but I don't think that's what you're going for. I think the glass packs are probably a little too loud for what you're wanting, so you're down to turbo's. But please don't stick chambered mufflers on it. If you do that you might as well go all the way and stick tall wheels and rubber band tires on it too.
  8. Mike VV
    Joined: Sep 28, 2010
    Posts: 2,585

    Mike VV
    from SoCal

    Ah...Flow Masters, they sound like boat transom exhaust.

    I'm going to buy a pair of SpinTech mufflers for my Stude wagon. One reason is that they make a very thin muffler.
    I'm using 2-1/4" exhaust pipes, and the mufflers are also, 2-1/4" thick. This way, I'll have no muffler hanging below the frame.

    Last edited: Oct 29, 2021
    X-cpe, bill gruendeman and HotRod33 like this.
  9. Almostdone
    Joined: Dec 19, 2019
    Posts: 706


    My A has a Chevy 348 with a pair of Flowmaster Super HP-2 with 2 1/2 inch exhaust ending at the rear of the car. That muffler is the middle of road in the Flowmaster loudness range. The car has Dynamat just about everywhere with Dynapad over that on the floor. The sound is not bad - we can still talk etc. on the freeway and it really gets with it when you get on it.


    Paulz and Fabulous50's like this.
  10. Fabulous50's
    Joined: Nov 18, 2017
    Posts: 451

    from Maine

    I also put on Flowmaster HPII in the 12" version. The perfect amount of sound, no drone. My 9.5:1 compression 352 and a mild cam makes enough noise to make itself known, but not too much that you cant talk in a drive.

    Long exhaust, 2" due to space restrictions, no H pipe, dynomatted and carpeted floor. 20211002_180935.jpg
    TCATTC likes this.
  11. jaracer
    Joined: Oct 4, 2008
    Posts: 1,482


    I've got Porters on my A, nice sound, not too loud.
    Truckdoctor Andy and Blues4U like this.
  12. I've got straight pipes on my 39 Ford with an SBC. You can barely hear the exhaust note inside the car running down the road. It barks when you get on it, but like I said it's pretty quiet inside the car.
    raven likes this.
  13. samurai mike
    Joined: Feb 24, 2009
    Posts: 524

    samurai mike

    i've ran four 2 1/2 turbo mufflers, very quiet. i have two cars with four glasspacks each, mellow v8 sound. i have a friend who is running two turbos and two glasspacks, very quiet inside, still can hear him coming up the driveway with a nice v8 sound. also maybe try a pair of big stock muffler off something like a 1970 cadillac for example, i don't think you will notice any power loss just rollin down the highway at 2200 rpm.
  14. MoePower
    Joined: Jul 12, 2004
    Posts: 219

    from Omro, WI

    I had a set of 40 series on an OT big block with full 2 1/2 exhaust and couldn't stand the drone inside the car with a full interior but they were cool when I was 25. I switched to 50 series thinking I'd quiet it down a bit . . . nope, still can't have a conversation in the car. That was a spectacular waste of money. Both sets are now going to be taking up space in the attic until someone with a fox body mustang wants them cheap or I move and they go in the scrap pile. Planning on Smithy's or Porters for my coupe.
    Last edited: Oct 29, 2021
    Blues4U and TCATTC like this.
  15. Love my DynoMax that haave a stainless steel spring loaded baffle inside.. sadly, they are not available anymore, but my electric cutouts add a whole 'nother dimension to driving. Get some quiet ones, with cutouts, and you will have the best of both worlds ! !
    impala4speed and olscrounger like this.
  16. TCATTC
    Joined: Oct 12, 2019
    Posts: 283


    Flowmasters = Interior resonance. (10's thru 50's)
  17. Mr48chev
    Joined: Dec 28, 2007
    Posts: 30,869


    Being as my car guy experience started in the 50's and 60's I have to go with Glass packs.
    I can still remember when I could tell who was going by the house without looking out the window by the sound of their pipes, especially when Ray Rojas drove his little lime green 51 Chevy hardtop with the split manifold and dual glass packs.
  18. TCATTC
    Joined: Oct 12, 2019
    Posts: 283


    1019211816a.jpg 36" Glasspacks
    AHotRod likes this.
  19. BamaMav
    Joined: Jun 19, 2011
    Posts: 5,490

    from Berry, AL

    Glass packs or old Thrush steel packs. Can't stand blownasters. Drone can be mostly eliminated with pipes out the rear in most cases. Pipes that exit in front of the rear will be louder and have more drone in my experience.
    anthony myrick and Just Gary like this.
  20. Paulz
    Joined: Dec 30, 2018
    Posts: 78


    I HATE the way the chambered Flowmasters sound. But I really like the sound of the Super HP2 Flowmasters on my 463" Pontiac powered International. And the size was perfect for the space I was putting them in. The price of them is a bit stout though.
    Fabulous50's likes this.
  21. jim snow
    Joined: Feb 16, 2007
    Posts: 1,477

    jim snow

    X2. Good advice right there. Been running turbos since 99. Can’t beat them.jmho. Snowman
    lothiandon1940, Blues4U and Just Gary like this.
  22. I like the generic turbo mufflers. Many brands, all similar. Give a deeper tone than glasspacks, which to me sounds better. Glasspacks have more popping sound.
    Just Gary and Blues4U like this.
  23. Hotrodderman
    Joined: Jun 18, 2006
    Posts: 88


    I've got generic glasspacks on my roadster that are about 20 years old. They sound good and are not burnt out. My F100 has a set of Thrush turbo mufflers on and are quiet at idle and throaty sounding when I get on it with a Yblock. Highway driving it has a nice mellow sound not loud.
    Just Gary likes this.
  24. Fabulous50's
    Joined: Nov 18, 2017
    Posts: 451

    from Maine

    Keep in mind that the Flowmaster HPII is not a chaimbered muffler. It is a stainless glass pack with a perforated baffle in it. Glass pack sound, with no popping.

    I too cannot stand that 80s chaimbered raspy sound for they typical "flowmaster".
    Blues4U and Paulz like this.
  25. SS327
    Joined: Sep 11, 2017
    Posts: 811


    Hollywood deep throat, I mean deep tone mufflers. Or Thrush Hush power.
  26. anthony myrick
    Joined: Sep 4, 2009
    Posts: 10,073

    anthony myrick

    Cheap long glass packs. Off too loud, add a short one. :)
    I do like the hush power mufflers.
  27. I run these in my Ford and they do get better with age. Still a little loud inside the car, even with a full exhaust. I may try adding a small extension to get the noise out from under the rear bumper. I have no package tray or trunk lid gasket which lets sound in.
  28. blazedogs
    Joined: Sep 22, 2014
    Posts: 488


  29. blazedogs
    Joined: Sep 22, 2014
    Posts: 488



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