Quieter 4 inch muffler

General engine tech -- Drag Racing to Circle Track

Moderator: Team

dfarr67
Expert
Expert
Posts: 861
Joined: Sat Jul 27, 2013 7:14 pm
Location:

Quieter 4 inch muffler

Post by dfarr67 »

Bit of an oxymoron but had enough raunchiness of the straight through Flo Pro muffler. Different application- it's a street 383 cid truck but there's a lot of experience here. Before you say it the wrong pipe size, you're probably right but for now it's staying. Have about 24-40 inches length to play with. Not sure if a better quality Magnaflow (straight through) will be any different, probably looking at Donaldson chambered diesel type muffler or a 'bus' muffler. Advice welcome.
brandonu
Member
Member
Posts: 75
Joined: Thu Nov 25, 2010 11:18 am
Location: Lore City, Ohio

Re: Quieter 4 inch muffler

Post by brandonu »

I used 4" Magnaflows on my 997HP 62 Bel Air and love it. I've been around several supposed mufflers in the 4" range and did not like any other than these. I have a video of startup and a 4500 launch, but I can't upload it. It says invalid extension (.mov)

If you have an email or can tell me how to change the extension of the file, I will gladly send it along.
User avatar
67RS502
Expert
Expert
Posts: 764
Joined: Wed Apr 20, 2005 12:57 pm
Location: Houston Tx.
Contact:

Re: Quieter 4 inch muffler

Post by 67RS502 »

Do you have tail pipes after the mufflers?
If not, just stick some 3 1/2" Dynomax ultraflos on it, with a reducer before the mufflers.
If its a street deal - its always better having packing type muffers, as they tend to knock down the low rpm noise more,
as in normal street driving rpm range, opposed to baffled mufflers which are loud at low rpm.
67 camaro
girly rollers on pumpgas:
420 - 641hp BretBauerCam, 1.39, 9.79 @ 137.5
383 - 490hp 224/224, 1.56, 10.77 @ 124.6
502 - 626hp 252/263, 049s 1.44, 10.08 @ 132.7
62 Nova cruiser
383/200-4R/12-bolt w 373s
224/224 HR cam
1.57 10.97 @ 121.2
dfarr67
Expert
Expert
Posts: 861
Joined: Sat Jul 27, 2013 7:14 pm
Location:

Re: Quieter 4 inch muffler

Post by dfarr67 »

Yes currently full exhaust with hi flo metal cat, with tailpipe at bumper. Kinda embarrassing going down the street (and some people pay for this) I knew the new muffler might be an issue but had to try it as it came with the SS kit for a 6.5 GM diesel. I've had the big ultraflow in SS but it recently rotted out inside. Looking for something else. Magnaflow keeps coming up, any experience with Spintech- they have some big sizes.
peejay
Guru
Guru
Posts: 1946
Joined: Tue Aug 10, 2010 9:16 pm
Location:

Re: Quieter 4 inch muffler

Post by peejay »

The exhaust shrinks in volume as it cools during its path down the exhaust system. The tip can be a lot smaller than the main exhaust system and not pose a restriction at all.

Depending on power level, you could probably restrict the tip down to 2" or less and not suffer any for power loss, and it will cut exhaust noise and drone dramatically. Especially if you can fit the restriction a ways inside the tailpipe.
travis
Guru
Guru
Posts: 1611
Joined: Sun Mar 15, 2009 5:31 am
Location:

Re: Quieter 4 inch muffler

Post by travis »

I’m assuming this is a single 4” system?

I’ve got a dual 3” in/single 3” out custom spin tech “RV” 8000 series muffler on my bone stock L31 ‘99 Suburban 3/4 ton. I love the way it sounds...it may be a touch loud at idle but no drone and much quieter at cruising speed than anything else I tried. I tried about 5 different exhaust configurations using no muffler, dual 2 1/2” straight through Pypes M80’s, dual 2 1/2” Flo-pro chambered mufflers, a summit 3” in/dual 3” out turbo muffler reversed, and then finally this spin tech. Being that the suburban is basically a big box, any drone or resonance becomes unbearable very quickly.

Perhaps a 4” spin tech with a 3.5” or 4” straight through resonater would do the trick.
bob460
Expert
Expert
Posts: 560
Joined: Thu Sep 26, 2019 6:19 am
Location: Australia

Re: Quieter 4 inch muffler

Post by bob460 »

dfarr67
Expert
Expert
Posts: 861
Joined: Sat Jul 27, 2013 7:14 pm
Location:

Re: Quieter 4 inch muffler

Post by dfarr67 »

https://spintechmufflers.com/street-muf ... trucks-rv/

Which material is best- I usually go SS but is regular steel better at sound damping, big price difference? Also looked into muffler inserts- very little information for reviews.
dfarr67
Expert
Expert
Posts: 861
Joined: Sat Jul 27, 2013 7:14 pm
Location:

Re: Quieter 4 inch muffler

Post by dfarr67 »

Look like a split flow, I think I ran accross these in searches- but very little info.
travis
Guru
Guru
Posts: 1611
Joined: Sun Mar 15, 2009 5:31 am
Location:

Re: Quieter 4 inch muffler

Post by travis »

dfarr67 wrote: Thu Oct 17, 2019 8:03 pm https://spintechmufflers.com/street-muf ... trucks-rv/

Which material is best- I usually go SS but is regular steel better at sound damping, big price difference? Also looked into muffler inserts- very little information for reviews.
I went with regular steel on mine, and after 3 years it still looks fine. These aren’t made out of thin sheet metal...they are beefy and will should last a very long time.
dfarr67
Expert
Expert
Posts: 861
Joined: Sat Jul 27, 2013 7:14 pm
Location:

Re: Quieter 4 inch muffler

Post by dfarr67 »

Whats the scoop on these multi cores- Borla is expensive but these are crazy....but I'll pay if they work well. Next to no reviews.

Borla 400069 XR-1® Multi-Core 4" Center-Center 23"x5.5"x8.5"
travis
Guru
Guru
Posts: 1611
Joined: Sun Mar 15, 2009 5:31 am
Location:

Re: Quieter 4 inch muffler

Post by travis »

dfarr67 wrote: Sun Oct 20, 2019 12:29 pm Whats the scoop on these multi cores- Borla is expensive but these are crazy....but I'll pay if they work well. Next to no reviews.

Borla 400069 XR-1® Multi-Core 4" Center-Center 23"x5.5"x8.5"
Dynatech makes a 4” split flow design like that...it is seriously loud
User avatar
midnightbluS10
Expert
Expert
Posts: 933
Joined: Sun Oct 20, 2013 8:41 am
Location: Shreveport, LA

Re: Quieter 4 inch muffler

Post by midnightbluS10 »

Personally, I'd probably go with a 3" in/out Dynomax Super Turbo and call it a day. They've been proven to flow quite well and they aren't loud at all.
JC -

bigjoe1 wrote:By the way, I had a long talk with Harold(Brookshire) last year at the PRI show. We met at the airport and he told me everything he knew about everything.It was a nice visit. JOE SHERMAN RACING
Racer71
Pro
Pro
Posts: 324
Joined: Mon Jun 24, 2019 12:36 pm
Location:

Re: Quieter 4 inch muffler

Post by Racer71 »

I’ve had spin tech on a 820 hp 408 sbf on the street and they were ok not much difference in sound level than a flow master just a different tone, granted this was 15 years ago. Then went to flow masters on the next engine which was 366” ex cup build and they were crazy loud. The diesel truck muffler might be worth a try, I used to have several around where cust would buy a diesel exhaust then have us remove muffler within a few months cause it wasn’t loud enough lol. I run magnaflow on both of my Porsche’s I’ve been happy with them, fair mix of sound and not crazy noise level. Is this single 4” or dual.
dfarr67
Expert
Expert
Posts: 861
Joined: Sat Jul 27, 2013 7:14 pm
Location:

Re: Quieter 4 inch muffler

Post by dfarr67 »

This is a single 4in.
Post Reply