...

Go Back   Lateral-g Forums > Lateral-G Open Discussions > Open Discussion
User Name
Password



Reply
 
Thread Tools Display Modes
  #1  
Old 04-06-2024, 06:10 PM
69hugger's Avatar
69hugger 69hugger is offline
Senior Member
 
Join Date: Feb 2014
Location: Minneapolis, MN
Posts: 475
Thanks: 147
Thanked 88 Times in 46 Posts
Default Help quiet down this LT4 please

I recently bought a '71 Blazer with an LT4. It is a stock crate engine with stainless headers into a 3" dual exhaust with X pipe. Has Magnaflows on it and tailpipes all the way straight out the back. Sounds great at idle, but is so loud under even medium throttle, something needs to done about it.
I am not up to date on what the go-to mufflers are for those of us who want a reasonable sound level inside and for the neighbors when I leave home.
Seems to me I read something somewhere that Hooker Blackhearts might be what I'm looking for. While I want some rumble, pretty much the quieter the better.
Thanks for any help on this.
__________________
Bill


'69 Camaro / 534 BBC / DSE Built
'67 C10 / LS-3 w/Magnuson / Roadster Shop Chassis (SOLD)
'71 Blazer / LT4 / 8L90 / Roadster Shop Chassis / Ride Tech Air Susp.
Reply With Quote
  #2  
Old 04-06-2024, 07:10 PM
WSSix WSSix is offline
Lateral-g Supporting Member
 
Join Date: Nov 2008
Location: Dunwoody, GA
Posts: 6,478
Thanks: 1,026
Thanked 712 Times in 555 Posts
Default

What length are the Magnaflows? They might make a longer version of the same muffler. Also, add catalytic converters if you don't have them already.
__________________
Trey

Current rides: 2000 BMW 540i/6 and 86 C10.

Former ride: 1979 Trans Am WS6: LT1/T56, Kore 3 C5/6 brakes, BMW 18in rims
Reply With Quote
The Following User Says Thank You to WSSix For This Useful Post:
camcojb (04-06-2024)
  #3  
Old 04-06-2024, 08:10 PM
camcojb's Avatar
camcojb camcojb is online now
Administrator
 
Join Date: Jul 2004
Location: Wilton, CA.
Posts: 12,905
Thanks: 5,583
Thanked 1,596 Times in 717 Posts
Default

Yes, the longer ones are quieter. Seen good luck with resonators inline in the pipes.
__________________
Jody

PAST CAR PROJECTS

Like Lateral-G on Facebook!

Follow Lateral-G on Instagram!

SPECIAL THANKS TO:
Jacob Ehlers and Amsoil for the lubricants and degreasers for my 70 Chevelle project
Shannon at Modo Innovations for the cool billet DBW bracket
Roadster Shop for their Chevelle SPEC Chassis
Dakota Digital for their Chevelle HDX Gauge Package
Painless Performance for their wiring harness

Ron Davis Radiators for their radiator and fan assembly.
Baer Brakes for their front and rear brakes

Texas Speed and Performance for their 427 LS Stroker
American Powertrain for their ProFit Magnum T56 kit
Currie Enterprises for their 9" Third Member
Forgeline for their GF3 Wheels
McLeod Racing for their RXT street twin clutch
Ididit for their steering column
Holley for their EFI and engine parts
Lokar and Clayton Machine for their pedals and door and window handles
Morris Classic Concepts for their 3 point belts and side mirrors
Thermotec for their heat sleeve and sound deadening products
Restomod Air for their Tru Mod A/C kit
Mightymouse Solutions for their catch can
Magnaflow for their 3" exhaust system
Aeromotive for their dual Phantom fuel system
Vintage Air for their new Mid Mount LS front drive
Hydratech Braking for their hydroboost system
Borgeson for their stainless steering shaft and u joints
Eddie Motorsports for their hood and trunk hinges and misc parts
TMI Products for their seats, door panels, and dash pad
Rock Valley Antique Auto Parts for their stainless fuel tank
Reply With Quote
The Following User Says Thank You to camcojb For This Useful Post:
69hugger (04-07-2024)
  #4  
Old 04-06-2024, 10:45 PM
69hugger's Avatar
69hugger 69hugger is offline
Senior Member
 
Join Date: Feb 2014
Location: Minneapolis, MN
Posts: 475
Thanks: 147
Thanked 88 Times in 46 Posts
Default

They look like they are the 5x8x18 size. Can’t measure them right now but based in the 3” pipe size, they look like that size to me.
Can’t go much if any thicker as the truck lays frame. Could add cats or resonators if they would provide significant sound reduction.


Sent from my iPhone using Tapatalk
__________________
Bill


'69 Camaro / 534 BBC / DSE Built
'67 C10 / LS-3 w/Magnuson / Roadster Shop Chassis (SOLD)
'71 Blazer / LT4 / 8L90 / Roadster Shop Chassis / Ride Tech Air Susp.
Reply With Quote
  #5  
Old 04-07-2024, 04:29 AM
srode1 srode1 is offline
Senior Member
 
Join Date: Jan 2021
Location: Cincinnati Ohio
Posts: 191
Thanks: 165
Thanked 71 Times in 50 Posts
Default

No personal experienc, but testing and other people's reports I have seen says Borla Pro XS will be your best bet for quiet and power. I have seen a couple posts from people on other sites about blackheart being too loud for their tastes.
Reply With Quote
The Following 2 Users Say Thank You to srode1 For This Useful Post:
69hugger (04-07-2024), camcojb (04-07-2024)
  #6  
Old 04-07-2024, 08:53 AM
dhutton dhutton is offline
Senior Member
 
Join Date: Nov 2006
Location: Mountain Springs, Texas
Posts: 1,893
Thanks: 1,106
Thanked 486 Times in 268 Posts
Default

Resonators as mentioned above.
Reply With Quote
The Following 2 Users Say Thank You to dhutton For This Useful Post:
69hugger (04-07-2024), camcojb (04-07-2024)
  #7  
Old 04-09-2024, 02:13 PM
Ns RS's Avatar
Ns RS Ns RS is offline
Lateral-g Supporting Member
 
Join Date: Sep 2010
Posts: 218
Thanks: 37
Thanked 101 Times in 42 Posts
Default

Quote:
Originally Posted by 69hugger View Post
I recently bought a '71 Blazer with an LT4. It is a stock crate engine with stainless headers into a 3" dual exhaust with X pipe. Has Magnaflows on it and tailpipes all the way straight out the back. Sounds great at idle, but is so loud under even medium throttle, something needs to done about it.
I am not up to date on what the go-to mufflers are for those of us who want a reasonable sound level inside and for the neighbors when I leave home.
Seems to me I read something somewhere that Hooker Blackhearts might be what I'm looking for. While I want some rumble, pretty much the quieter the better.
Thanks for any help on this.
Running stock lt4 with black heart exhaust 3” x pipe etc and I had the opposite problem as you - the black heart system is great but was too quiet with resonators so I cut them out and they work great - so yes resonators
Reply With Quote
The Following 2 Users Say Thank You to Ns RS For This Useful Post:
69hugger (04-09-2024), camcojb (04-09-2024)
  #8  
Old 04-10-2024, 07:41 AM
Hotwire Hotwire is offline
Junior Member
 
Join Date: Sep 2020
Location: Greensboring, NC
Posts: 16
Thanks: 21
Thanked 27 Times in 15 Posts
Default

Unfortunately it's the 3" exhaust that's getting you. I've run into the same issue with my car.

I ended up putting 3" high flow magnaflow cats on the collectors of my longtubes and it greatly reduced the sound level in the car, can carry on conversations easily while cruising now. I am also running an Elgin E1839P cam, has a lot of overlap, and the exhaust stank at idle, the cats cleaned it up, don't smell like I mowed the lawn after driving around now.
__________________
*Jeff*
Project Salty - 1964 4 door Malibu, beaten, neglected, red headed foster child
Cammed LQ4 / T56 Swap Project Thread <-click to read! 😁
Reply With Quote
The Following 2 Users Say Thank You to Hotwire For This Useful Post:
69hugger (04-10-2024), camcojb (04-10-2024)
  #9  
Old 04-10-2024, 11:01 AM
bk2life bk2life is offline
Member
 
Join Date: Nov 2023
Location: Phx, Az
Posts: 69
Thanks: 2
Thanked 103 Times in 55 Posts
Default

Quote:
Originally Posted by Hotwire View Post
Unfortunately it's the 3" exhaust that's getting you. .
This right here.

amazing going from 3 inch to 2.5 inch would be.

Cats help alot, as theyre 'mini' mufflers, and you can always add a second muffler.

Some people like resonators, but, those are straight through 'glass packs' and they will tone it down, but, theyre still plenty loud.

Your exhuast system looks nice, but, it needs to be redesigned for what you want.
Reply With Quote
The Following 2 Users Say Thank You to bk2life For This Useful Post:
69hugger (04-10-2024), camcojb (04-10-2024)
  #10  
Old 04-10-2024, 02:17 PM
rstone rstone is offline
Junior Member
 
Join Date: Nov 2009
Posts: 16
Thanks: 8
Thanked 2 Times in 1 Post
Default

Another thing to consider is a blazer is not the same as a car or a pickup, as the passenger compartment extends all the way to the back bumper. Cars and Pickups have a separation from the exhaust tips. Insulation in the floor of the bed is essential to deadening the sound. I had a 76 blazer with no sound deadening. It sat 4" off the ground and had cam with a lot of overlap and the old flowmaster 5 chambers on it dumpt to the ground in front of the rear end. You could carry on conversation in it. all though it did set off every car alarm I passed.
Reply With Quote
The Following 2 Users Say Thank You to rstone For This Useful Post:
69hugger (04-10-2024), camcojb (04-10-2024)
Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -5. The time now is 06:12 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright Lateral-g.net