Enter your username:
Do you want to login or register?
  • Forgot your password?

    Login / Register



    Page 2 of 3 FirstFirst 1 2 3 LastLast
    Results 21 to 40 of 43
    1. #21
      Join Date
      Oct 2004
      Posts
      2,428
      Country Flag: United States
      Quote Originally Posted by 67-LS1 View Post
      Yup. My bad for going off track.
      I did get something back from Walker Exhaust (Walker, Dynomax, Thrush) and they suggested a Super Turbo number 17748 or a Quiet-Flow number 21856. Both the same size and similar in size to the Flowmasters I have now.
      The Quiet-Flow 21856 is used in 70’s Cadillacs with 7.7 liter (500 ci) engines with single exhaust.
      With two of them being fed from my 217 ci engine it may suck noise out of the car next to me!
      The Walker is great for whisper quiet as many have reported this and other forums. It does really neck down though. One of the Amazon reviews has a great picture through the muffler pipe and states it necks down to 1 3/4".: https://www.amazon.com/Walker-21856-...ustomerReviews.

      Red Forman: "The Mustang's front end is problematic; get yourself a Firebird."


    2. #22
      Join Date
      Aug 2008
      Location
      jacksonville,fl
      Posts
      964
      Country Flag: United States
      I wouldn't put much focus onto a tv show's limited choice muffler test. For a v-6 in the real world, choosing one for sound would be the thing to do. Within certain parameters you may not ever feel a power difference from one to another. I'd definitely search for sound clips of what camaro & caddy cts owners are running. brands like borla aren't cheap, but a little more goes into their construction & design.
      Long tube headers could improve your overall sound.
      I got my wife a 2012 cts coupe years ago with basically the same engine. Doesn't have the low rpm power of an LS, but it is pretty cool above 5000 rpm. I'd love to do something with the exhaust on it one day.

    3. #23
      Join Date
      Jun 2001
      Location
      Los Angeles
      Posts
      5,721
      Country Flag: United States
      I'll be the oddball thought......

      What about using the stock muffler(s) from the OEM application? There is a tremendous amount of engineering that goes into modern cars to reduce NVH.

      If that's not an option, low 300hp NA engines could pretty comfortably be exhausted by a single 2.5" system. What about putting two mufflers in series? Single 2.5" pipe, then perhaps a transverse muffler behind the axle housing? Keep the current left/right muffler but have a single 2.5" tube on the drivers side feed the LH muffler, the output crossed over to the RH side, and a single output over the axle exiting on the RH side/rear. Fitment may be difficult.

      A transverse option could be added to your current setup but would loose most of the custom tailpipe.

      In any case using the largest case absorbtion type muffler will certainly get you closer to the lower NVH goal than the reflective type Noisemasters. I tossed those to the curb 20+ years ago.
      Last edited by CarlC; 02-25-2021 at 11:46 PM.
      VaporWorx. We Give You Gas http://www.vaporworx.com

    4. #24
      Join Date
      Jun 2001
      Location
      Los Angeles
      Posts
      5,721
      Country Flag: United States
      Quote Originally Posted by jlcustomz View Post
      I wouldn't put much focus onto a tv show's limited choice muffler test......
      This, but also applies to many other parts as well. The parts used on the shows have been paid to be there by the manufacturer to be an advertisement. Hence, there is little objectivity since the show does not want to put the parts in a bad light. More than once some so-called show expert expounds on the wonderful-ness of a part/system that I know is a POS, mis-applied, etc., all in the name of making a for-profit show. Our own shared experiences go a lot farther in my book.

      Rant off....
      VaporWorx. We Give You Gas http://www.vaporworx.com

    5. #25
      Join Date
      Apr 2009
      Location
      Michigan
      Posts
      255
      Country Flag: United States
      I agree that most car themed TV shows are a joke, but I think the Engine Masters show (and associated competition) is about as legit as they come. Of course it would be better if they tested more mufflers, but this is the closest thing to an objective test I've seen, and I think it would take more effort than it's worth to fudge the numbers. If any "regular guys" have done back to back muffler dyno tests with noise measurements, we'd love to see your data.

      I also like to use OEM parts whenever possible for the reasons mentioned, but I don't see how you could package the giant, irregularly shaped OEM modern Camaro or CTS mufflers under a Chevelle.
      - Ryan

    6. #26
      Join Date
      Sep 2010
      Location
      Martinez, CA
      Posts
      135
      Country Flag: United States
      I did think about going to a single exhaust. I could cap one side of my X pipe or even use the unused leg for a Helmholtz tube. If a 500 ci Cadillac can breath through a single 2.5” I’m reasonably sure I’d be safe with 217 ci. I would just remove one side but then I’d have just one tip under the muffler so would probably want to replace then tail pipe with one that’s tucked up more with a turn down. At least I wouldn’t be advertising the single exhaust pipe.
      The muffler definitely has to be an offset in-offset out and the closer to 25” oa length the better to match where the Flowmasters will come out.
      I should have never gone with the Flowmasters to start with.
      1966 Chevelle, 3.6L/217 CI, 4 cam direct injected V6, 6 speed auto, full Hotchkis suspension, 4 wheel Wilwood discs, white w/red interior, cowl hood. 3260 lbs w/full tank. Built for 35 mpg. So far 32.

    7. #27
      Join Date
      Apr 2001
      Location
      The City of Fountains
      Posts
      15,559
      Country Flag: United States
      Quote Originally Posted by 67-LS1 View Post
      I did think about going to a single exhaust. I could cap one side of my X pipe or even use the unused leg for a Helmholtz tube. If a 500 ci Cadillac can breath through a single 2.5 Im reasonably sure Id be safe with 217 ci. I would just remove one side but then Id have just one tip under the muffler so would probably want to replace then tail pipe with one thats tucked up more with a turn down. At least I wouldnt be advertising the single exhaust pipe.
      The muffler definitely has to be an offset in-offset out and the closer to 25 oa length the better to match where the Flowmasters will come out.
      I should have never gone with the Flowmasters to start with.
      You can install an exhaust cut-out in the H-pipe so you can have dual or single exhaust at the flip of a switch.

      Andrew
      1970 GTO Version 2.0
      1967 Cougar build
      GM High-Tech Performance feature
      My YouTube Channel Please Subscribe!
      Instagram @projectgattago
      Dr. EFI
      I deliver what EFI promises.
      Remote Holley EFI tuning.
      Please get in touch if I can be of service.

      "You were the gun, your voice was the trigger, your bravery was the barrel, your eyes were the bullets." ~ Her

    8. #28
      Join Date
      Jan 2000
      Location
      Thousand Oaks California
      Posts
      9,790
      Country Flag: United States
      I have always heard that a 5" muffler is an oxymoron. LOL!
      Larry Callahan
      Founder/Administrator of Pro-Touring.com, G-Machines.com and HostMyJunk.com
      To advertise on Pro-Touring.com click here

    9. #29
      Join Date
      Nov 2018
      Posts
      317
      Country Flag: United States
      My wife is also one who wants her cars silent. If she had her way the engine would make no noise at all. So, I've had some experience in making them quieter. You didn't say if you had cats or not, but if not I'd suggest adding a set of performance cats to the system. They will cut noise a bit, and will clean up the exhaust's smell with no noticeable decrease in power. To do the bare minimum to the system you have, a pair of 2.5" in/out Walker Quiet Flow turbo style mufflers will be super effective. If they're still too loud after, a pair of 1 foot glass packs after the axle will cut the rest of the noise. We used to have a 96 Tahoe with a pair of Flowmasters backed by glasspacks, and the tires made more noise than the engine. I'd really suggest going 2.5" in/2" out and redo the exhaust after the mufflers with 2" though.

    10. #30
      Join Date
      Sep 2010
      Location
      Martinez, CA
      Posts
      135
      Country Flag: United States
      Quote Originally Posted by Vimes View Post
      My wife is also one who wants her cars silent. If she had her way the engine would make no noise at all. So, I've had some experience in making them quieter. You didn't say if you had cats or not, but if not I'd suggest adding a set of performance cats to the system. They will cut noise a bit, and will clean up the exhaust's smell with no noticeable decrease in power. To do the bare minimum to the system you have, a pair of 2.5" in/out Walker Quiet Flow turbo style mufflers will be super effective. If they're still too loud after, a pair of 1 foot glass packs after the axle will cut the rest of the noise. We used to have a 96 Tahoe with a pair of Flowmasters backed by glasspacks, and the tires made more noise than the engine. I'd really suggest going 2.5" in/2" out and redo the exhaust after the mufflers with 2" though.
      I do have cats on my car. Probably the only 66 in the world with them. They are 2.5 outlets so I went with a 2.5 Pypes system with an X pipe.
      I ordered two 22393 Quietflow mufflers today. They are the same OA length as the Flowmasters so a real easy swap.
      And speaking of Flowmasters on Tahoes being, this is comical..

      https://sfbay.craigslist.org/eby/pts...272276693.html

      Ill try to take before and after videos with sound and post them.
      1966 Chevelle, 3.6L/217 CI, 4 cam direct injected V6, 6 speed auto, full Hotchkis suspension, 4 wheel Wilwood discs, white w/red interior, cowl hood. 3260 lbs w/full tank. Built for 35 mpg. So far 32.

    11. #31
      Join Date
      Sep 2010
      Location
      Martinez, CA
      Posts
      135
      Country Flag: United States
      Update.
      I got the QuietFlow mufflers and installed them. They are certainly not quiet. Possibly louder than the Flowmasters and at a higher tone. Now it sounds like Honda with a Fart can tip. The drone appears to be gone but the mufflers are not anywhere near what I was looking for.
      Im wondering if a dual 2.5 system is to large. Could it be echoing inside the pipes? Could flow be so low that the muffler is ineffective?
      With the drone gone Im guessing my next step would be resonators. Does anyone have any experience that would tell me to add the before the mufflers or after the mufflers by the rear bumper?
      Im looking for dead silence. Zero noise.
      1966 Chevelle, 3.6L/217 CI, 4 cam direct injected V6, 6 speed auto, full Hotchkis suspension, 4 wheel Wilwood discs, white w/red interior, cowl hood. 3260 lbs w/full tank. Built for 35 mpg. So far 32.

    12. #32
      Join Date
      Nov 2018
      Posts
      317
      Country Flag: United States
      Sorry to hear my recommendation didn't work out, but I can't see how they'd have been louder than Flowmasters. I also don't understand how they'd be giving you a fartcannon sound. The Tahoe I ran them on was super quiet, to the point that under WOT it was about as loud as the stock exhaust was at idle.

      On the smaller exhaust, yes, and that was another recommendation I made. A smaller exhaust is a quieter exhaust. On a 3.6L a dual 2 inch is plenty, particularly from your usage as a cruiser. The Tahoe I was running had dual 2.5s with a 5.7L, and it was plenty of exhaust for it.

      So, if you're willing to risk another suggestion from me - have your exhaust shop redo the exhaust after the mufflers. Knock it down to dual 2 inch, and put the longest glasspacks that will fit after the axle. They can reuse your existing tips with the glasspacks, and painting them black will hide them up under there if they can't get them tucked up.

    13. #33
      Join Date
      Oct 2004
      Posts
      2,428
      Country Flag: United States
      Because of the internal neckdown within the muffler, you effectively stepped up the relative pipe size on the tailpipe. As I said in post 7, reducing tailpipe size lowers the tone and sound level. So, guess what stepping up the tailpipe size does? I don't know if the late model trucks with raspy and stupid loud exhaust are popular in your area (seem to be abundant around mine), but they typically get that (similar to the fart can Hondas) by having a 4" exhaust tailpipe on an otherwise 3" system.

      Reduce your tailpipes to 2". It still may not completely meet your goals as you would probably be much better off with a 2 1/4" from the cats to the mufflers, but it'll put you a lot closer that what you have now.
      Red Forman: "The Mustang's front end is problematic; get yourself a Firebird."

    14. #34
      Join Date
      Sep 2010
      Location
      Martinez, CA
      Posts
      135
      Country Flag: United States
      The drone is gone which Im happy about but the sound level is still too loud and the pitch is actually higher. At idle I guess Id say theyre quieter but once off idle theyre not.
      Last night I read that a dual system with two mufflers is louder than a single system with the same muffler. To test that theory today Im going to remove one leg of the exhaust at the X pipe and cap it. Basically turning the X into a Y and having single exhaust.
      Ill try to take before and after sound clips.
      1966 Chevelle, 3.6L/217 CI, 4 cam direct injected V6, 6 speed auto, full Hotchkis suspension, 4 wheel Wilwood discs, white w/red interior, cowl hood. 3260 lbs w/full tank. Built for 35 mpg. So far 32.

    15. #35
      Join Date
      Aug 2004
      Location
      Red Deer, Alberta, Canada
      Posts
      1,301
      Country Flag: Canada
      Quote Originally Posted by 67-LS1 View Post
      The drone is gone which Im happy about but the sound level is still too loud and the pitch is actually higher. At idle I guess Id say theyre quieter but once off idle theyre not.
      Last night I read that a dual system with two mufflers is louder than a single system with the same muffler. To test that theory today Im going to remove one leg of the exhaust at the X pipe and cap it. Basically turning the X into a Y and having single exhaust.
      Ill try to take before and after sound clips.
      If you want silent... I think you should go to a single exhaust system, scrap your tips you want to keep. Tuck the exhaust nice and high with a turn down that is not visible.
      Matt
      72 Chevelle 370ci LS Turbo. Speedtech equipped.
      Instagram: Cst_koon

    16. #36
      Join Date
      Nov 2018
      Posts
      317
      Country Flag: United States
      Heh heh, and you said you didn't want to rework anything, just replace the mufflers. If a complete rework had been an option, a single 2.5 in/dual 2 in out setup, with dual 2 inch over the axle and out the back, would have been the way to go. If you decide to do the turn-down, do it as far to the rear of the car as you can. Turn-downs aim the exhaust at the ground, and this can cause sound to be bounced off the ground and back into the car if dumped in front of the axle.

    17. #37
      Join Date
      Sep 2010
      Location
      Martinez, CA
      Posts
      135
      Country Flag: United States
      I blocked off one tail pipe today and the difference was mind boggling. The sound dropped by half or more. It went from load and obnoxious to really pleasant and low.
      This first link is a complete dual system.
      https://drive.google.com/file/d/19XE...w?usp=drivesdk

      This second link is just one muffler and tail pipe.
      https://drive.google.com/file/d/1SW2...w?usp=drivesdk
      1966 Chevelle, 3.6L/217 CI, 4 cam direct injected V6, 6 speed auto, full Hotchkis suspension, 4 wheel Wilwood discs, white w/red interior, cowl hood. 3260 lbs w/full tank. Built for 35 mpg. So far 32.

    18. #38
      Join Date
      Oct 2004
      Posts
      2,428
      Country Flag: United States
      With the x-pipe blocked at the tip, you now have the longest Helmholz Resonator exhaust ever devised!
      Red Forman: "The Mustang's front end is problematic; get yourself a Firebird."

    19. #39
      Join Date
      Sep 2010
      Location
      Martinez, CA
      Posts
      135
      Country Flag: United States
      Quote Originally Posted by 68Formula View Post
      With the x-pipe blocked at the tip, you now have the longest Helmholz Resonator exhaust ever devised!
      Yeah, it could be. The final plan is to pull off the passenger side system at the X pipe and cap it there. So the extra pipe will be only about 6. If the drone returns I can use this opening to experiment with different length tubes to try to kill it again.
      Im also going to add resonators after the cats and before the X on both legs.
      1966 Chevelle, 3.6L/217 CI, 4 cam direct injected V6, 6 speed auto, full Hotchkis suspension, 4 wheel Wilwood discs, white w/red interior, cowl hood. 3260 lbs w/full tank. Built for 35 mpg. So far 32.

    20. #40
      Join Date
      Apr 2001
      Location
      The City of Fountains
      Posts
      15,559
      Country Flag: United States
      Quote Originally Posted by 67-LS1 View Post
      Yeah, it could be. The final plan is to pull off the passenger side system at the X pipe and cap it there. So the extra pipe will be only about 6. If the drone returns I can use this opening to experiment with different length tubes to try to kill it again.
      Im also going to add resonators after the cats and before the X on both legs.
      Why not install a motorized exhaust cutout to block off the second pipe? That way you can go from single to dual exhaust with the flip of a switch.

      Andrew
      1970 GTO Version 2.0
      1967 Cougar build
      GM High-Tech Performance feature
      My YouTube Channel Please Subscribe!
      Instagram @projectgattago
      Dr. EFI
      I deliver what EFI promises.
      Remote Holley EFI tuning.
      Please get in touch if I can be of service.

      "You were the gun, your voice was the trigger, your bravery was the barrel, your eyes were the bullets." ~ Her

    Page 2 of 3 FirstFirst 1 2 3 LastLast