Quieter Mufflers for my 77 with 351W

[bskiusaf]

I have long tube headers with a H pipe setup and flowmasters exiting behind the axles on each side on my 77 with 351W. I have to drive it from California to Virginia this spring and it is too loud.

At highway speeds the exhaust makes it difficult to hear the radio unless it is really loud.

Trying to avoid the fatigue from the noise.

Any recommendations on a good set to swap out without restricting the flow too much? Would CATs quiet it down?

 

[Godwick]

Check out Heus' thread on the topic. He went with a walker quietflow and likes it, I believe.

 

[blubuckaroo]

Try stock style mufflers. Most of the aftermarket mufflers are made for drivers who like more noise.%)

 

[stock1970]

I had 40s on my duals with long headers and 351w and it was so loud, I had to turn it off to order food.. lol.. I went with some cheap quit mufflers and it is better but still not like a buick.. lol.. I dont think long headers and short broncos will ever be quiet..

 

[Sporto]

Check out Heus' thread on the topic. He went with a walker quietflow and likes it, I believe.

Agreed. I followed his thread and built a similar setup with pipe sections from a Pep Boys. I used a SS Magnaflow muffler (two in and one out), it could be quieter, but it sounds really nice. Not to mention it is tucked away near the frame, and does not rattle or bang against anything.
;D

 

[Crawdad]

Hues did a great thread on this. His was way quieter than mine. I was looking for a quieter muffler lastyear. My EB came with side pipes (straight)out the side. I went with BCs shorty ceramic headers and their muffler exhaust pipes (so very ez 2 install). I went with the biggest muffler MagnaFlow had (2-in 2-out, 2.5"s all 4 inlet/ outlets). Its quieter than before but I sorta wish it was quieter. I hunt a lot and I don't wanna ring the bell when I pull up to my favorite spot. The next step for me is to pipe the exhaust pipes straight out the rear corners and add carpet to interior. That will help reduce the in-cab rumble. Good luck!

 

[Heus33]

Thanks for the props guys.

Here's a copy/paste of the info:

------------------------------------------

Here's a few setups I've run:

If you're looking for low noise dont get the Magnaflow - get a Quiet Flow 2100 from napa (OEM for a Silverado) - here's a thread I posted about my install - I was very happy with the results.
http://www.classicbroncos.com/forums/showthread.php?t=168161&page=3

For comparison, here's a vid of my 2into1 that I did on my blue truck (with the 3 chamber magnaflow):

FYI I used about six feet of 2.5" pipe, two 90* elbows, two collectors and a quick dump for a tailpipe:

[youtube]u98OuHwFWys[/youtube]

I got a lot of drone from this setup so I swapped the muffler for a Walker Quiet Flow 21400 is great! Sounds like a truck again. The muffler is a monster at 29" long.

The sound is way more subdued than the other mufflers. Not whisper quiet (I dont think thats possible) but no where near as annoyingly loud as it was before. Cruising at 40+ and all I can hear is the wind and the tires.


Here's the specs on the muffler:

Cost $120
Body Configuration : Dual Offset Inlets - Center Outlet
Body Diameter : 7" x 9"
Body Length : 29"
Muffler Inlet I.D. : 2 1/2"
Muffler Outlet I.D. : 2 3/4"
Muffler Shell Overall Length : 24"

Lifetime warranty too. Here's this one for comparison.

[youtube]rfUMYvGibRA[/youtube]

Here's the last bronco. Version 1 was mildly built 302 with long tubes and 2.5" exhaust with glasspacks routed straight out the back:

[youtube]tM4sv_RnVNY[/youtube]

I swapped out the glasspacks for Summit Turbo mufflers, added an H pipe and routed the exhaust out behind the rear tires. This one was the best of the bunch - low rumble, not loud...just perfect.

[youtube]njlFsDiG0xw[/youtube]

 

[Sporto]

Wow Tom,
That is a nice looking top you got there on the red one. Where'd ya get it?

Sorry that you had to let that one go.

R

 

[Heus33]

Wow Tom,
That is a nice looking top you got there on the red one. Where'd ya get it?

Sorry that you had to let that one go.

R

Salt in the wounds Richard...salt in the wounds....

 

[aaronmichorn]

Maybe use a couple of short cherry bombs as resonators. I have run the gamut. Went form dual cherry's(too loud), to a stock style(too quiet), to a small body magnaflow SI/SO. I love the sound now, and it is very reasonable at low rpm's.

If I already had something with decent sound, I would just add a couple resonators inline. I did this with my dodge truck and it helped reduce it a little bit. Depends on what you are going for. I guess I'm just saying don't neuter the poor boy. You might regret it later.

 

[bskiusaf]

Thank you for all the advice. Like I said I just need it quieter. I am not at the point where i have to turn it off to order at a drive thru, but not far from that. What are the advantages of the 2 into 1 versus the H pipe dual that I have? I had not thought about using cherrybombs as resonators, is there enough room under a Bronco to get cherrybombs with mufflers?

 

[bskiusaf]

I had 40s on my duals with long headers and 351w and it was so loud, I had to turn it off to order food.. lol.. I went with some cheap quit mufflers and it is better but still not like a buick.. lol.. I dont think long headers and short broncos will ever be quiet..

What did you mean by Long headers and short Broncos? Are the shortie headers any better than the long tube headers for noise?

 

[RT]

Thank you for all the advice. Like I said I just need it quieter. I am not at the point where i have to turn it off to order at a drive thru, but not far from that. What are the advantages of the 2 into 1 versus the H pipe dual that I have? I had not thought about using cherrybombs as resonators, is there enough room under a Bronco to get cherrybombs with mufflers?

I did just that one time , two dynomax and two cherrybombs in front. Good sound but the bombs never seemed to last .

 

[bskiusaf]

351 W Exhaust

What are the advantages/disadvantages of the 2 into 1 versus the H pipe dual that I have? Do you lose more power by using 2 into 1 versus dual with two mufflers?

 

[bad 68]

Thank you for all the advice. Like I said I just need it quieter. I am not at the point where i have to turn it off to order at a drive thru, but not far from that. What are the advantages of the 2 into 1 versus the H pipe dual that I have? I had not thought about using cherrybombs as resonators, is there enough room under a Bronco to get cherrybombs with mufflers?

Where in the hell did you find a place to install a H pipe?????
I would like to add an H pipe but it would have to go up over the rear driveline up near the floor and I don't think that would help with heat or noise issues

 

[bskiusaf]

Where in the hell did you find a place to install a H pipe?????
I would like to add an H pipe but it would have to go up over the rear driveline up near the floor and I don't think that would help with heat or noise issues

I got it done at a good shop in Great Falls MT, will have to look up the receipt. They did a good job bending the pipe to keep the heat and noise away from the floor boards and no issues with the driveline clearances. If I can figure out how to post a picture I will post one showing the H pipe setup with duals.

If you go to my gallery it has the picture of the Hpipe setup. I can not figure how to upload a picture to the forum directly only how to attach a URL.