LS swap exhaust too loud.... Options

[04ls1gto]

Just got my 71 suburban out for the maiden voyage after swapping a ly6 6.0 and 6l90. Exhaust setup is speed engineering 1 7/8 long tubes, magnaflow mufflers to true dual 2 1/2" SS out the back. It is way to loud, do I swap mufflers? Add h pipe? Add resonators or maybe a combination off all three. Let me know what your setup is and how you like it

[mongocanfly]

Hard to imagine it's to loud in a burb...resonators may help...diff mufflers would also make a diff....I have a set of walker super quite for mine...I have a set of magflow...not magnaflow..on my other truck dumping in front of the axle and it's not to loud...

[Overdriven]

Magnaflow mufflers are available in different lengths and styles (traditional oval shape, round), what do you have? H pipe doesn’t have much effect on sound level. Swapping mufflers is probably your best bet, chambered mufflers are usually quieter.

[04ls1gto]

Here's what I have

https://www.summitracing.com/parts/mpe-11256

[SBTork]

Originally Posted by 04ls1gto

Here's what I have

https://www.summitracing.com/parts/mpe-11256

I have a similar setup on my '85 Suburban. Mine has TBSS manifolds, 2 1/2 pipes, 2 magnaflow mufflers (exactly the same as yours) and I have it dumping just above the rear bumper. Mine is pretty loud, excessively loud at about 2,100-2,400 rpm lol. But it's suuuper quiet at idle and under light throttle around town. I've been thinking and I might switch to the larger case magnaflow mufflers in the future. I have 1 single larger case magnaflow muffler on my '83 K5 and it's a lot quieter but still has a good tone. I'd recommend you switching to some larger case magnaflow mufflers and I bet you'd be happy with that.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[davepl]

Mine's near silent with manifolds and cats. It's the headers, for a start, I think. I have Dynomax and they're fairly quiet until opened up.

[04ls1gto]

I ordered a set of resonators to install. well see if that helps. There is no room for a bigger muffler the way its setup unfortunately

[SBTork]

Originally Posted by 04ls1gto

I ordered a set of resonators to install. well see if that helps. There is no room for a bigger muffler the way its setup unfortunately

That makes sense, good idea. Let us know how the resonators help!

[Willie Makeit]

6.0 liter LS engines are very very hard to make quiet without the use of cats and/or resonators.

[72MARIO]

Both my swaps are very quiet. Both have camaro manifolds and catalytic converters. The suburban has super 40 flowmasters I can hardly hear it now before with the 327 it was abnoxous.

The 1967 truck has magnaflows and its wisper quiet catnt hear it at all with the wondows up

[Rich84]

My 6.0 has 2.5 dual exhaust out behind the rear tires and was way too loud with 40 flowmasters. The droan was hideous. Much better with the added resonators.

[04ls1gto]

Originally Posted by Rich84

My 6.0 has 2.5 dual exhaust out behind the rear tires and was way too loud with 40 flowmasters. The droan was hideous. Much better with the added resonators.

Headers of manifolds? Resonators should be here today and plan is to install this weekend. Hopefully my brake issue is something simple

[Rich84]

Trailblazer SS manifolds.

[crazy longhorn]

My thoughts.....add the resonators, but do add the h pipe! The H will tame the sound a tad, give more mid power, & also "sweeten" the sound Longhorn

[04ls1gto]

Resonators are in, weather did not allow for a test drive as there's no wipers on the truck right now. Much quieter so hopefully thats it. Gonna drive it tommorow

[cornerstone]

I'm hoping the volume is to your liking, and looking forward to your thoughts after you get the chance to drive it. I will be in the same boat soon and really don't want a loud truck. Curious to see how and where you placed the resonators so any pictures would be great if possible.

[04ls1gto]

Originally Posted by cornerstone

I'm hoping the volume is to your liking, and looking forward to your thoughts after you get the chance to drive it. I will be in the same boat soon and really don't want a loud truck. Curious to see how and where you placed the resonators so any pictures would be great if possible.

I'll get picks of exhaust for you. It was a ***** to build with getting around trailing arms

[jjzepplin]

I had an h pipe on my 67 Firebird and it was very quiet with glasspacks dumped before the rear axle. It still set off car alarms with a very low tone. Tamed those glasspacks though. At high rpms, they did not rap like normal packs. I never liked them but at the time they were free. Subbed for info.

[04ls1gto]

Went for a test ride and exhaust is much better. Rasp is gone and sounds really good. Still a little loud but there is no sound deadoning in the truck. Seams like with every success comes a issue. Went for a 20 min ride, got back to shop and was checking a few things and the truck overheated. Electric fans stopped working and she was hot. Gonna dig into that issue this week, bad temp sensor maybe? Bad fan controller? Wiring issue?