Looking for a unicorn muffler.

[bovey]

I'm trying to keep my truck quiet. However, everything I'm doing to it makes is noisy. And noisy does not work in the city I call home.

No, moving is not an option.

I'm running a 427 LSX built by SDPC Raceshop, it makes 611 HP at 6100 RPM. Headers have been designed by Burns Stainless, triple step into 3.5 collectors. After that, it 's dual exhaust via twin Vibrant GESI cats and mufflers - all 3.5". Might side exit in front of the rear wheels, or just behind. Not exactly sure of design yet as I'm sorting out my fuel cell and dry sump oil tank location.

On my current 3" system, I've used 3" Flowmaster Delta 50s, and I'd like to be quieter.

Due to a large amount of engine setback, I may not have space for an "X" pipe.

Obviously, I'd rather not sacrifice power, but something with have to give.



Any thoughts or advice/brands on mufflers would be appreciated.

Thank you in advance.

[sheck44]

Ditch the Flowmasters ... Magnaflow, Borla would be a good place to start

Cheers
steve

[Protour_Pinto]

I wish that mufflers had a flow rating. I know its a tough thing because of engine size, and many other variables.

I plan on using a Bus Muffler on my truck, Im thinking it should flow well enough for a mild OG 500ci engine and keep it fairly quiet.

Have you thought about some OEM mufflers like on the newer Vettes, Mustangs and Hemis? I know some of the late model vettes have a vacuum operated valve that opens at higher RPMs.

[bovey]

Ditch the Flowmasters ... Magnaflow, Borla would be a good place to start Cheers steve

Thanks Steve. They are on my hit list. Thank you for the reco.

I wish that mufflers had a flow rating. I know its a tough thing because of engine size, and many other variables. I plan on using a Bus Muffler on my truck, Im thinking it should flow well enough for a mild OG 500ci engine and keep it fairly quiet.

Have you thought about some OEM mufflers like on the newer Vettes, Mustangs and Hemis? I know some of the late model vettes have a vacuum operated valve that opens at higher RPMs.

Interesting option. I looked up Vette mufflers and they are huge. I don't have a lot of space. However, while looking into this I found out that modding mufflers is actually a thing. Never thought of that option. People actually cut open mufflers and change them to suit their applications. Neat. Thanks again for your thoughts.

[Canon_Mutant]

Well, general rules you probably already know do apply. Size generally matters in this particular case. I put the largest Magnaflows I could fit behind my big block Olds in my 442 that are 5x11x22. I would have gone even larger but that is all that will fit. But, it has a really nice but mellow rumble at idle. Oh you can certainly hear it when your foot is in the fan but at highway speeds it will almost go quiet in the 1800-2200 rpm range the way I am geared.

What I do NOT know is what these huge diameter exhaust systems like yours add to this equation? I've got just 2 1/2 all the way back through high-flow Magnaflow Cats and I cannot begin to get the power I make to the ground . . . though my pro-touring transition mission I am on should be helping that significantly by this spring.

At least . . . that is the plan!

[HandOverFist]

I've seen it somewhere in print that a 2 into 1 w/collector system combined with a single specialty (large) muffler will quiet things down considerably while making more power throughout the rpm range.

[PRRC]

Try spin tech. We use them all the time in the shop.

[dirty rick]

Flow master 40 and 50 are aggressive sounding mufflers

Try a 70 series. http://www.flowmastermufflers.com/70-series/

[Dark Pursuit]

Dynatec Vt mufflers might be what you are looking for.

[TXsilverado]

Big straight through mufflers like stated. Magnaflow, borla, spintech...bigger the better. Quieter and better performing than flowmaster mufflers. Dual 3.5 is hard to tame down.

[camarodude87]

Magnaflow has always been the quite go to mufflers on ls1tech.

[sam 74]

Borla makes a good muffler and its quiet, i used the 16 inch XR1 on my 470 race motor and was able to use it on the street without getting a ticket for noise.

[Protour_Pinto]

Thanks Steve. They are on my hit list. Thank you for the reco.




Interesting option. I looked up Vette mufflers and they are huge. I don't have a lot of space. However, while looking into this I found out that modding mufflers is actually a thing. Never thought of that option. People actually cut open mufflers and change them to suit their applications. Neat. Thanks again for your thoughts.

Yeah, The vettes have some chunky mufflers, I have a set from a C6 in storage. They are 13"LX12"WX9"H. in the car they sit "Tall Ways" but I have cut the outlets off and rotated them in the past.

[bovey]

Hello everyone, thank you for your comments and suggestions. I'm currently speaking to Borla, Spintech and Magnaflow. Dynatek does not make a muffler over 3" so I am passing on them. Once I have all of the information, I will report back.

[Protour_Pinto]

Spintechs are good but run pretty hot.

[downl50]

I'm looking for something similar for a 580hp small block but 3" exhaust. I've been listening to Dynomax Super Turbos which are pretty inexpensive and quiet. Borla looks attractive but when you add in the resonators for their setup you're getting to $800 in just mufflers.

I've also heard Corsa is worth looking at. I had a hard time figuring out from Spin Tech's website what might make sense so prob worth the call.

I'll be interested to hear what you learn and go with!

[Charlie Brengun]

Perhaps adding more mufflers will make it a little less loud, something like dynomax race bullets near the headers and hooker aerochamers where your mufflers normally would be. Both are available in 3 1/2 inch.

[68sixspeed]

Also while it will lose a bit of hp, exhaust manifolds are quieter than headers. I'm surprised on a Vette how much louder headers alone are. Ls7 z06 manifolds have decent flow, only a 10-15hp loss on a 600hp motor.

As others mentioned ditch the flowmaster for a s-path turbo type muffler. I have magnaflow 3" on the camaro and they are good but not really quiet either. But the x/pipe magnaflow uses is a bit louder than a H-pipe too. An h-pipe will quiet a system a touch if you don't have a crossover. The old hooker super comp mufflers were quieter than the magnaflow.

[ilikeike]

I'm looking for something similar for a 580hp small block but 3" exhaust. I've been listening to Dynomax Super Turbos which are pretty inexpensive and quiet. Borla looks attractive but when you add in the resonators for their setup you're getting to $800 in just mufflers.

I've also heard Corsa is worth looking at. I had a hard time figuring out from Spin Tech's website what might make sense so prob worth the call.

I'll be interested to hear what you learn and go with!

My SBC 421 has similar HP (494 rwhp,before additional upgrades), Using 3" Magnaflow and a Pypes X pipe terminated at the axle.
It's pretty beastly sounding,I don't even think going over the axle would do much. But it sure sounds good when it's on the pipe.

[downl50]

Hello everyone, thank you for your comments and suggestions. I'm currently speaking to Borla, Spintech and Magnaflow. Dynatek does not make a muffler over 3" so I am passing on them. Once I have all of the information, I will report back.

Looking for something similar (550hp sbc, street driven Chevelle, looking for very quiet).

Suggestions from talking with the companies
Borla: XR1s with a second set of round mufflers after them. CrateMuffler will not handle over 450hp


Magnaflow
12289 is a 5x8x24inch muffler, sounds pretty good if it'll fit


SpinTech: XL Plus is 3x10x16. They also rec'd 3" to the muffler and then 2.5 out the back to reduce noise without much performance difference.


Interested to hear if anyone has experience fitting 2 sets or one of these larger mufflers.