We are currently running on the new domain and server: www.Speed-Talk.com

IMPORTANT: Update your bookmarks to https://www.speed-talk.com/forum/
(Right-click the URL and select "Bookmark this link")

Straight through mufflers

General engine tech -- Drag Racing to Circle Track

Moderator: Team

travis
HotPass
HotPass
Posts: 1119
Joined: Sun Mar 15, 2009 5:31 am
Location:

Straight through mufflers

Post by travis » Thu Jun 18, 2020 9:33 pm

Does case size and shape effect the sound level of straight through mufflers?

For example...all 2.5” straight through perforated core mufflers...3.5” or 4” diameter glass packs, vs something like a 6” or 7” round case dynomax ultra flow, vs an oval cased magnaflow?

I’ve been testing some mufflers on my truck...5 pairs so far. The 14” pypes M80’s and the 24” glass packs sound great at idle and low speeds, but at highway speeds they are just brutally loud. The 3 chamber pro-flo’s and Walker 22635’s (straight through perforated core but with a baffle in the middle) have about the right volume at speed, but no tone or character at all. And I just strapped on a set of dynomax super turbos that sound perfect on my other truck with the nearly stock engine, but are absolute stealth mufflers on the hotter 351w. I mean these things are whisper quiet with just a tiny bit of sound at idle or at WOT.

The 24” glass packs have the best sound at idle and low speed, but on acceleration or highway cruising they are just way too loud. I’m trying to find that happy medium

enigma57
Guru
Guru
Posts: 1847
Joined: Sun Oct 07, 2007 11:59 pm
Location: Galt's Gulch

Re: Straight through mufflers

Post by enigma57 » Thu Jun 18, 2020 10:16 pm

The DynoMax Super Turbos are my choice. Flow better than Flow Masters and attenuate the sound so they don't get you tickets nor drive you nuts on road trips.

If you really have to have a noisy exhaust, try electrically controlled cut outs. Either straight to open dumps or diverted through glass packs or steel packs but I don't know why anyone would want the noise. I'm into sleepers on the road. :D

Best regards,

Harry

dannobee
HotPass
HotPass
Posts: 231
Joined: Mon Nov 04, 2019 9:01 pm
Location:

Re: Straight through mufflers

Post by dannobee » Thu Jun 18, 2020 10:17 pm

Does the exhaust have a balance pipe or X-pipe connecting the two banks? That sometimes help get rid of the drone at freeway speeds.

travis
HotPass
HotPass
Posts: 1119
Joined: Sun Mar 15, 2009 5:31 am
Location:

Re: Straight through mufflers

Post by travis » Thu Jun 18, 2020 10:37 pm

enigma57 wrote:
Thu Jun 18, 2020 10:16 pm
The DynoMax Super Turbos are my choice. Flow better than Flow Masters and attenuate the sound so they don't get you tickets nor drive you nuts on road trips.

If you really have to have a noisy exhaust, try electrically controlled cut outs. Either straight to open dumps or diverted through glass packs or steel packs but I don't know why anyone would want the noise. I'm into sleepers on the road. :D

Best regards,

Harry
I’m not looking for noisy, just a nice tone and a moderate sound level. I love the super turbos and have run them on multiple vehicles, and they sound perfect on my other tamer truck, but literally on the ‘83 f150 they are quieter than my 2014 Honda Ridgeline at any point.

Maybe some 3” super turbos adapted to the 2.5” pipes would do the trick?

travis
HotPass
HotPass
Posts: 1119
Joined: Sun Mar 15, 2009 5:31 am
Location:

Re: Straight through mufflers

Post by travis » Thu Jun 18, 2020 10:40 pm

dannobee wrote:
Thu Jun 18, 2020 10:17 pm
Does the exhaust have a balance pipe or X-pipe connecting the two banks? That sometimes help get rid of the drone at freeway speeds.
No crossover of any kind, but also no drone at all with any of the mufflers. The straight throughs are just ridiculously loud...they sound really good at idle and low speed though

tjs44
HotPass
HotPass
Posts: 592
Joined: Thu Jul 07, 2005 2:30 pm
Location: long beach.ca

Re: Straight through mufflers

Post by tjs44 » Thu Jun 18, 2020 10:50 pm

Have you tried the Hushpowers?I have used a couple sets and really like them.Even better than the 14in super turbos.Tom

enigma57
Guru
Guru
Posts: 1847
Joined: Sun Oct 07, 2007 11:59 pm
Location: Galt's Gulch

Re: Straight through mufflers

Post by enigma57 » Thu Jun 18, 2020 11:31 pm

I'd definitely suggest adding a crossover (balance) pipe connecting the 2 banks, as its just more efficient on a full length muffled exhaust system. Either an H type or X type will work but make crossover same size as exhaust.

We did experiment with mufflers on Dan Miller's hemi that he ran at EMC over the years. Running an efficient muffler having inner flow tube 1 size larger than correct size exhaust tubing will usually equal flow of same exhaust with no mufflers at all. And yes, it will be a bit louder than same system with muffler sized same as exhaust tubing. Whether this will provide the sound you are after, only trying it will provide you with the answer though.

The good news...... Sounds as if you now have either a lifetime supply of mufflers on hand...... Or enough inventory to open your own muffler shop. :D

Happy Motoring,

Harry

travis
HotPass
HotPass
Posts: 1119
Joined: Sun Mar 15, 2009 5:31 am
Location:

Re: Straight through mufflers

Post by travis » Fri Jun 19, 2020 12:10 am

tjs44 wrote:
Thu Jun 18, 2020 10:50 pm
Have you tried the Hushpowers?I have used a couple sets and really like them.Even better than the 14in super turbos.Tom
Are you referring to the Flowmaster HP2’s? I’ve never tried them, or even heard them on anything that I know of.

F-BIRD'88
Guru
Guru
Posts: 7534
Joined: Tue Mar 27, 2007 6:56 pm
Location: Ontario, Canada

Re: Straight through mufflers

Post by F-BIRD'88 » Fri Jun 19, 2020 12:27 am

Have someone else drive the truck so you can evaluate the exhaust tone from outside at a distance...
There is a sweet sounding exhaust , then there is is a exhaust that just pisses every one off, including you eventually..
If the exhaust terminates under the truck VS at the rear bumper it is going to get old quick... The H pipe is a good idea.. I build my own custom mufflers.

Look what Ford did with the late Mustangs..
I took a California Special 6 Speed rag top for a ride .
As soon as you fire it up... Its like " Ya Baby"!!! (Austin Powers) ♪♪♪🇬🇧

GT50
HotPass
HotPass
Posts: 54
Joined: Mon Feb 15, 2016 6:00 pm
Location: Azores(Portgal)

Re: Straight through mufflers

Post by GT50 » Fri Jun 19, 2020 5:55 am

F-BIRD'88 wrote:
Fri Jun 19, 2020 12:27 am
Have someone else drive the truck so you can evaluate the exhaust tone from outside at a distance...
There is a sweet sounding exhaust , then there is is a exhaust that just pisses every one off, including you eventually..
If the exhaust terminates under the truck VS at the rear bumper it is going to get old quick... The H pipe is a good idea.. I build my own custom mufflers.

Look what Ford did with the late Mustangs..
I took a California Special 6 Speed rag top for a ride .
As soon as you fire it up... Its like " Ya Baby"!!! (Austin Powers) ♪♪♪🇬🇧
Can you show the inside of your custom muffler? If it's not top secret.

Truckedup
Guru
Guru
Posts: 2364
Joined: Mon Jan 21, 2013 2:41 pm
Location:

Re: Straight through mufflers

Post by Truckedup » Fri Jun 19, 2020 6:53 am

Many of the newer vehicles have a noticable exhaust sound, but it's a hollow artificial sound. Some performance mufflers also sound the same...
Motorcycle land speed racing... wearing animal hides and clinging to vibrating oily machines propelled by fire

tjs44
HotPass
HotPass
Posts: 592
Joined: Thu Jul 07, 2005 2:30 pm
Location: long beach.ca

Re: Straight through mufflers

Post by tjs44 » Fri Jun 19, 2020 10:09 am

Travis,yes,I have them on a 63 421 Tempest right now.Had them on my 455 69 bird and pulled them to try the 14in Superturbo.Hated the 14s,tried the 18 ST and hate them.Going to put the HPs back on.My 428 RA V in the bird has developed a bad drone at 2000 and have been fighting it.Only real change on the car was going to a shorty header.I never had the issue with the HPs.FWIW,Tom

Walter R. Malik
Guru
Guru
Posts: 4836
Joined: Tue Jul 24, 2012 11:15 am
Location: Roseville, Michigan (just north of Detroit)
Contact:

Re: Straight through mufflers

Post by Walter R. Malik » Fri Jun 19, 2020 10:39 am

travis wrote:
Thu Jun 18, 2020 9:33 pm
Does case size and shape effect the sound level of straight through mufflers?

For example...all 2.5” straight through perforated core mufflers...3.5” or 4” diameter glass packs, vs something like a 6” or 7” round case dynomax ultra flow, vs an oval cased magnaflow?

I’ve been testing some mufflers on my truck...5 pairs so far. The 14” pypes M80’s and the 24” glass packs sound great at idle and low speeds, but at highway speeds they are just brutally loud. The 3 chamber pro-flo’s and Walker 22635’s (straight through perforated core but with a baffle in the middle) have about the right volume at speed, but no tone or character at all. And I just strapped on a set of dynomax super turbos that sound perfect on my other truck with the nearly stock engine, but are absolute stealth mufflers on the hotter 351w. I mean these things are whisper quiet with just a tiny bit of sound at idle or at WOT.

The 24” glass packs have the best sound at idle and low speed, but on acceleration or highway cruising they are just way too loud. I’m trying to find that happy medium
In a "straight through" use the biggest volume case size which fits into the space provided.
http://www.rmcompetition.com
Specialty engine building at its finest.

enigma57
Guru
Guru
Posts: 1847
Joined: Sun Oct 07, 2007 11:59 pm
Location: Galt's Gulch

Re: Straight through mufflers

Post by enigma57 » Fri Jun 19, 2020 2:21 pm

X 2!!

HB

travis
HotPass
HotPass
Posts: 1119
Joined: Sun Mar 15, 2009 5:31 am
Location:

Re: Straight through mufflers

Post by travis » Fri Jun 19, 2020 3:20 pm

tjs44 wrote:
Fri Jun 19, 2020 10:09 am
Travis,yes,I have them on a 63 421 Tempest right now.Had them on my 455 69 bird and pulled them to try the 14in Superturbo.Hated the 14s,tried the 18 ST and hate them.Going to put the HPs back on.My 428 RA V in the bird has developed a bad drone at 2000 and have been fighting it.Only real change on the car was going to a shorty header.I never had the issue with the HPs.FWIW,Tom
What do you hate about the ST’s?

How are the HP’s at a 3000-3200 rpm cruise?

You mentioned drone at 2000 rpm after switching to shorties. I noticed a similar deal when I was running shorties with the 14” ST’s...no drone or resonance anywhere except at around 1700-1800 rpms. They had a wicked resonance in a very narrow rpm range...which just happened to be about parking lot speed lol

Post Reply