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Old 12-26-2019, 07:36 PM   #1
Daron65
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Muffler suggestions

My 71 C20 is way to loud. It has a Blueprint 355 with headers dumping into 3 inch pipes, that turn out before the rear tires. It has generic straight cherry bombs about 18 inchs from each header.
I like the deep rumble, but its way too loud.
What do you all suggest?
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Old 12-26-2019, 07:48 PM   #2
Ziegelsteinfaust
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Re: Muffler suggestions

You need bigger or longer mufflers.

Although personally I have never been told I need anything bigger or longer.

Glass packs can be quite tame if you go for the longer ones while still having almost unrestricted flow. Personally I think Magna Flows are quieter at this point while still maintaining high flow. Although I have never done or seen a back to back test.

You can get turbo style mufflers if the loss of a few hp does not bother you or you just like a little rumble.

Also running the exhaust out the back have the effect of reducing cabin noise. Once again at the cost of almost 20 hp/tq vs dumped like you have it now.
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Old 12-26-2019, 08:06 PM   #3
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Re: Muffler suggestions

Thank you.

I do like the side exhaust. I just dont have the funding to buy new mufflers to only find out they also are way to loud. I would like to keep what HP I have.
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Old 12-26-2019, 08:30 PM   #4
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Re: Muffler suggestions

What hp level do you think your at.

At the crank.
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Old 12-26-2019, 08:36 PM   #5
Daron65
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Re: Muffler suggestions

The Dyno sheet from Blueprint showed mid 430s. It does run very well, for all my needs.
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Old 12-26-2019, 08:44 PM   #6
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Re: Muffler suggestions

check out this youtube video. https://www.hotrod.com/articles/engi...ers-episode-17 It may help your decision.
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Old 12-27-2019, 12:56 AM   #7
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Re: Muffler suggestions

If you really want to tame the exhaust, put a pair of Cadillac mufflers on it. You ever heard a Cadillac roar by when it passed you? Nope!? One Caddy muffler tames a 500 CI engine! Two of them will do you nicely. It's what I'm going to do when I go through my exhaust, if I live that long, since it may be many years before I do it.
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Old 12-27-2019, 01:21 AM   #8
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Re: Muffler suggestions

The problem with Cadillac mufflers is they don't come in 3" diameter. Do you have room for longer glass packs? That is what I am using on my Burban in a 2 1/2" diameter and it is one of the quietest rigs I have built. I too have the pipes exiting in front of the rear wheels.
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Old 12-27-2019, 10:43 AM   #9
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Re: Muffler suggestions

I am running Magna flows on a Big Block with short headers, all 3" pipe and have the turn outs right in front of the rear tires. This configuration sounds great. Has a very nice rich and deep tone. You know the truck is running, but its not annoying.
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Old 12-27-2019, 12:51 PM   #10
Ziegelsteinfaust
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Re: Muffler suggestions

I forgot to add if you get resonators they sure help out with sound. Especially drone at highway speeds.

But the biggest or longest magna flow would be my first step to fixing your sound level issues.
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Old 12-27-2019, 03:12 PM   #11
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Re: Muffler suggestions

I've always really like the turbo mufflers. They are rather tame. Loud enough for me, but quiet enough I can start it up at 6 am.
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Old 12-27-2019, 06:54 PM   #12
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Re: Muffler suggestions

Put a pair of these Dynomax Super Turbos on my bone stock 350/350 combo in my 72 C10 with pipes all the way to the back with pipes exiting behind the back wheels. I used 2 1/4 pipes but you can get 2 1/2's with these too. I cant post video on here, from my computer, cause you could hear them on the truck. Pic shows where I have exhaust exiting and its the same for both sides. PM me an email address and I'll send you video of my truck running if yu want to hear it.

http://www.dynomax.com/catalogsearch/result/?q=17747
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Old 12-27-2019, 08:33 PM   #13
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Re: Muffler suggestions

I like Borla
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Old 12-28-2019, 09:03 PM   #14
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Re: Muffler suggestions

I have the flow master 44s over the axle and they sound great. Nice rumble but tame in the cab.
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Old 12-28-2019, 09:28 PM   #15
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Re: Muffler suggestions

Quote:
Originally Posted by HO455 View Post
The problem with Cadillac mufflers is they don't come in 3" diameter. Do you have room for longer glass packs? That is what I am using on my Burban in a 2 1/2" diameter and it is one of the quietest rigs I have built. I too have the pipes exiting in front of the rear wheels.
Nobody makes a 3" muffler, stock, that I know of. I missed the 3" part of his question, though. I'd either neck down the system to 2-1/2" at the collector or run the exhaust all the way out the back if I was married to a 3" system.
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Old 12-28-2019, 09:40 PM   #16
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Re: Muffler suggestions

On my 57 3200 I am running a set of flow master 50 series and they dump on the ground just in front of the axle. Sound is awesome and not too loud but very noticeable.

On my 1972 Camaro I am running a set of flow master 40 series, they exit out the back of the car and are somewhat louder but not obnoxious and have that muscle car rumble.

Pretty sure both of these mufflers are available for a 3" exhaust system.
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