360 la headers & straight pipe

[340six]

This thread reminds me of Jay Leno story of his dad ordering a new car.
He checked off 7 Liter ( 428?) And muffler delete.
When his dad's car came in he was mad and said something like brand new car and hole in the muffler.
The sales guy said no see ya checked off muffler delete.
And Jay said guys at times pulled up we to to race his dad at lights.
At the time of the filming was building a tribute to his dad's old car.
Sure it is on YouTube aired long long ago.

 

[MILO]

I got fined big bucks once for excessive noise

 

[Ironracer]

Just keep those that live by you and the cops off your *** with

View attachment 1716065074

Always wanted to try em. My neighbors used to hear me roll in from the bar at 3:30 am. They said it'd barely even make them notice, cause they KNEW it was me. Made em feel safer!

 

[Ironracer]

Myth, been proven otherwise a few times, here’s the deal.

Headers or not, the amount of pipe after the collector or the manifold or header should be dyno tested to provide the best possible length to provide the best possible amount of torque possible. After this, a pressure wave cancellation box equal to a minimum of the C.I.D. of the engine should be installed on each pipe.

From here, if one should choose to use a muffler or not, the engine is now making the best low end torque and will retain maximum power throughout the rest of the dyno run.

Any back pressure is just performance limiting. Period. It is exactly the same as me limiting you exhaling while you’re running. You can breathe in as deep as possible, no problem. But I’ll only allow you to exhale so much. Just by this alone, not exhaling all that you can, there is now a limitation on the amount of air you can breathe in. Your overall performance in running is now curtailed. Apply this to the engine.

Silencing an engine after the pressure wave cancellation box is another topic since the OP wants maximum sound.

To this end, after your header extension length is found, cut your cars exhaust there and let it run like that. Running a full length exhaust pipe to the rear of the car/bumper could very well be reducing power since the pressure wave tubing is nullified and engine breathing is cut short as described above.

Adding a pressure wave box for maximum torque and continuing the exhaust pipe without a muffler may indeed possibly reduce sound. I don’t know for sure. I’ve never done that myself. Nor do I know of anyone that has.

The header extension pipe should be the same size as the pipe diameter of the header collector where all 4 pipes come together. Normally this is 3 inches on small blocks. Keep that size throughout the rest of the exhaust system. This should produce maximum sound. Stepping up to a 3-1/2 or larger pipe to run the length of the car may help in more obnoxious sounds.

I agree, Fir Max Power, and have read a few articles pertaining to that. Just seems to me, open headers, or headers with some length of pipe, Jack's Yer bottom end.... yes it's nice on the high side of the RPMs... just my perspective....Ain't gonna say much else, I Better "Follow the Science" lol

 

[Ironracer]

I got fined big bucks once for excessive noise

They do it down here, but for those that "pump up the bass" , i.e , amped stereos, mainly, in tourism areas

 

[SpeedThrills]

I agree, Fir Max Power, and have read a few articles pertaining to that. Just seems to me, open headers, or headers with some length of pipe, Jack's Yer bottom end.... yes it's nice on the high side of the RPMs... just my perspective....Ain't gonna say much else, I Better "Follow the Science" lol

Look at it this way; millions of race cars over the years have no mufflers. I'b be willing to bet there's a good reason for that.

 

[doogievlg]

Always wanted to try em. My neighbors used to hear me roll in from the bar at 3:30 am. They said it'd barely even make them notice, cause they KNEW it was me. Made em feel safer!

I have some love them. I don’t really care too much for the look at me stuff. So I keep them closed in parking lots or in my neighborhood. But I love the sound of my engine with them open.

 

[Rat Bastid]

I got fined big bucks once for excessive noise

I got pulled over for “excessive” noise once. Got a BIG fat ticket.

I took the ticket to court and smoked the cops *** who wrote it. Apparently neither he nor the city attorney’s office could actually READ the code.

The funny thing is my wife worked for the city attorney’s office. I did the online research and she verified what I found (and the some) in the law books at work.

Needless to say, the 2014 city picnic was not a happy event because I rolled in there with my car, and it sounded exactly the same.

And the cops we not happy 5 months later.

And I keep a copy of the paperwork in the car, in the event I get pulled over again for that I can save the court time and end it right there.

 

[dodgedude37]

The OP's motor combo is what we use to call a smog motor. He needs to modify to get the volume he wants, & then he will probably have to muffle.

 

[MopaR&D]

I agree, Fir Max Power, and have read a few articles pertaining to that. Just seems to me, open headers, or headers with some length of pipe, Jack's Yer bottom end.... yes it's nice on the high side of the RPMs... just my perspective....Ain't gonna say much else, I Better "Follow the Science" lol

You aren't necessarily "wrong", that is generally how it works because hardly anybody bothers to bolt 3-foot or longer collector extensions onto their headers. Backpressure and velocity are directly related, think about if you've ever been drinking through a straw and you pull the end of the straw out of your mouth before stopping suction, your drink will continue to flow out of the straw and spill on your face and shirt lol. The longer the straw is, the longer the column of fluid and the stronger the effect is. BUT the longer the straw is, the more force is required to draw the same amount of fluid through.

 

[jos51700]

OP is confusing the deafening roar that a child hears with a stock cammed 340 and some aftermarket muffs, that the rest of us hear as a low rumble with occasional loudiness, and is allowing the fog of childhood to skew what he's trying to recreate. Little kid ears hear a lot more than even young adult ears, and all ears will hear more than OP's, shortly.

But if OP insists on competing to be the stupidest, gayest, loudest a-hole on the planet, my decade in Harley/moto world makes this my time to shine:

Please note: There are no women in this photo. Not even in the distant background.

OP, you want a diverging cone. Even the short-bus sheet metal shop can whip this right out if you don't have a Harley shop with a Parts Unlimited account nearby. Attach anywhere along your unmuffled system, and it'll get you what you want: All the attention your parents never gave you.

Still not loud enough? Well, it's probably YOU not being able to hear anymore, but just make the big end bigger and/or the long part longer. The slash cut on the end will direct the noise. I recommend straight down if they're at the back of the car and you want to reflect the *ahem* noise off the pavement and then out to your admiring throngs, or you can orient them up to direct noise into the cabin if this exercise is simply because the world revolves around you, and that's where you'll be sitting.

 

[Ironracer]

OP is confusing the deafening roar that a child hears with a stock cammed 340 and some aftermarket muffs, that the rest of us hear as a low rumble with occasional loudiness, and is allowing the fog of childhood to skew what he's trying to recreate. Little kid ears hear a lot more than even young adult ears, and all ears will hear more than OP's, shortly.

But if OP insists on competing to be the stupidest, gayest, loudest a-hole on the planet, my decade in Harley/moto world makes this my time to shine:

View attachment 1716067666
Please note: There are no women in this photo. Not even in the distant background.

OP, you want a diverging cone. Even the short-bus sheet metal shop can whip this right out if you don't have a Harley shop with a Parts Unlimited account nearby. Attach anywhere along your unmuffled system, and it'll get you what you want: All the attention your parents never gave you.

View attachment 1716067664

Still not loud enough? Well, it's probably YOU not being able to hear anymore, but just make the big end bigger and/or the long part longer. The slash cut on the end will direct the noise. I recommend straight down if they're at the back of the car and you want to reflect the *ahem* noise off the pavement and then out to your admiring throngs, or you can orient them up to direct noise into the cabin if this exercise is simply because the world revolves around you, and that's where you'll be sitting.

Lol