[kaw550]

I am planning to remove my headers and go back to manifolds. I am trying to quiet the engine noise down. The engine is in a 72 bronco with a weiland 2p180 manifold and an edelbrock 1405 carb. It has dual exhaust with newer passenger truck mufflers.

I want to quiet down the engine noise. I normally run with a soft top or no top at all.

Will there be a big loss in power?
Will it be quieter?

It came with the headers and i have never had a car that i switched to or from headers .

 

[vinniekq2]

headers are usually the best improvement you can make. going backwards if you take them off,power wise,but it will be a lot quieter

 

[9tcoupe]

Leave the headers and get a better muffler. Changing back to manifolds won't make that much of a difference in the volume.

 

[JeffB]

Where are the tailpipes exiting? If you ran them all the way to the rear it would be less noisy,the stock heads on your Bronco do not breathe well on the exhaust side anyway removing the headers and going back to manifolds is a big step backwards :nono:

 

[kaw550]

Well, the exhaust kit I had was from headman. It came with turbo mufflers. Way too loud.

I went to a local parts house and bought two mufflers by their dimensions. I basically went with the same inlet and outlet but in the longest size I could fit ( They are by Walker).

The tailpipes exit behind the rear wheels.
Right now it has a real raspy sound. It fits the truck but I want it to be more of a driver.

Would it be more than 10hp drop? It has more than enough power (it's the small body style). With 33" tires and 2.5" of lift, I really can't get on it too hard.

 

[vinniekq2]

do you have a cross over in your exhaust system?

 

[geezer69]

ear plugs are cheap. just kiddin a bit. i dont think its gona be much quieter with the manifolds.strait out the back mite help more.

 

[kaw550]

No cross over. I was planning to do that over the winter but I had to take the engine out for the freeze plugs. I thought it be a good time to swap in the manifolds. I don't have enough room to remove the headers with the engine in.

Does the crossover lower the noise level or just change the sound? I could still do it with the manifolds.

 

[vinniekq2]

The x does both,changes the sound and lowers volume.If you have a drone at lower RPM then that will mostly go away. I run 3 inch exhaust and decent power,its not what I call excessively noisey,when you add full power the sound level goes up

 

[kaw550]

I will have to look into it. I was going to weld in an "H" It may be a better idea to have a local shop install and "X"

I don't have a drone. It's pretty quiet when cruising. I am trying to quiet down the noise during normal acceleration.
It's pretty loud when I get on it. I don't mind that

10 well maybe 15 years ago I would have loved it.

 

[vinniekq2]

"H" works mostly the same as an "X" for sound

 

[onlyfnway]

I would run a dynomax super turbo! They are very quite. I ran them on a 70 nova! long tubes 2.5 inch exhaust with xpipe and it was very nice even at 6700rpm.

 

[JeffB]

You could do it a simple way also by using resonator tips like these: Exhaust Tip Chrome 2 5 x 9 2 00 in Resonator | eBay they have internal baffles to reduce noise and since they are a straight thru design flow should be OK.

 

[cobalt327]

The difference in HP from cast iron manifolds to headers will be at least 10 hp/10 ft-lb torque. I would use an H connection aft of the collector and before the mufflers, and change to a quieter muffler while keeping the headers.

You can go on youtube and listen to hundreds of muffler/exhaust combos to see what muffler you may like, but I would use a quieter turbo-style muffler w/the pipes exiting as far rearward as practical. Run the pipes out a couple inches past the body- don't end the pipes under the body.

 

[gearheadslife]

easy fix, install a radio.. :thumbup::welcome:

here is what I'd do if the "ticking,pinnn'n" header noise is an issue,,
as changine to cast iron will not change the tail pipe noise..

find headers made with thicker pipe walls, headers made for racing have thinner wall pipe than "most street headers" I say most, because elcheapo ones might have thin pipes also..

if the noise you want gone is still from the tail pipe end, add resinators..

ceramic coating helps some also..
so does header wrap, but the rape holds water and can make the headers rust out faster, depending on where you live..
if the noise is the pinn'n pinn'n ring of the headers, the wrap really muffles it .

also, diy bedliner on the underside of the hood. helps.. as your hood more than likely has nothing..
also some fat mat under the rubber or carpet at the fire wall.. big help..

 

[kaw550]

Do the resonator tips really work?

I do have a Hoodliner but no carpet or padding. The carpet has been ordered and should be in this week

I have a box of Dynamat from a neighbor and may add carpet mat. I have the top off all summer so dont want to add to much in case the floor gets wet.

I am considering the DIY lizard skin and maybe the bedliner.


If I go too far it will end up sounding like a hybrid.