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Pathologic Opeler
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my plans

i will have the muffler guy track down a cherry bomb II or the magnaflow 12237.thank you TEK and bosco

looks like the excelsior manta magnaflow 11214 wont work for a GT, 4x9 is too wide..will hit the cable bracket..i think..thank you excelsior..resonator looks like it would fit in the muffler position..


here is my plan after i get a muffler..advise as needed...

i will be 2in back from the "Y"...cat.conv. flange will allow me to pull the y and soak the 4 bolts off the exhisting stove pipe manifold...sprint will go in..and hopefully it will line up from there.
 

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Pathologic Opeler
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resonated tip

car is too loud but fun ...I just got my car back from carx..they said no room for an additional glass pack..car has a small "emco brand "muffler

will resonated tips help? where can i get some?
 

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Pathologic Opeler
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too loud

more than a rumble.....

i went to "wendys"...a person rolled their window up...

people are staring...or am i self conscious?

CAR FEELS REAL FAST!

on the positive side...i like the blend from the y pipe to the 2 in ...
it is a solid set up...but a little loud and it looks a little goofy where the pipes exit from 2 to 4..i was told..it has to be that way...

what do you guys (and possible 1 gal) think?
 

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I don't know Bucky, I think for aesthetic appeal I would want them to end right at an imaginary vertical line from the edge of the rear end at the trim strip. That's where I plan to have mine exit when I get it all done. I don't want the vacuum created back there to discolor the paint by having the exhaust swirl around the rear end sheetmetal.

Ron
 

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Pathologic Opeler
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ansa tips?

would this not stick out and be quieter?
 

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Pathologic Opeler
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glass pack

i guess i am going to add a glass pack..the guy at carx is going to
special order
a real skinny one that will fit..he says he can put it on in front
of the muffler?

1-is there anyone here with a glass pack?
2- will the ansa resonated muffler tips that ogts sells help at all?

my car sounds like there is no muffler at all...
 

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Seriously,

I think you need to take your car to a different exhaust shop. When I got my flowmaster system done, I went to two places that said they did not think it would fit, so I kept looking. Eventually I took it to a place that had all kinds of pictures of custom exhaust systems that had been installed. I brought the installer the flowmaster and the tips he said no problem. An hour later the system was done, but it was too loud.

I went to Checker and bought a 15.00 24" long by 4" wide glass pack and they put it on in half an hour and it helped quiet the exhaust down.

If the guy can't do what you are looking for, go somewhere else. If you get a really thin glasspack put on it will not make much difference. The thicker the glasspack the more sound absorbing material it will have and the more sound attenuation you will get. Your exhaust is too loud because of the small muffler the shop insisted on installing.

Check with a place that sells magnaflow exhaust products. Magnaflow makes a round muffler that is essentially a glass pack that is 4" in diameter called the "magnapack" and in addition to the muffler you already have on the car it should help make it more quiet. If the guy says it wont fit on you car, go somewhere else.


Just my 2 cents,

Nathan Acree
Albuquerque New Mexico
 

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Opel Junkie
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dual tips

i haven't done it yet, but i plan on bringing exhaust tips out the back, then angling them up slightly (about 10-15 degrees), and then cutting them off with a bevel cut equivilant to the up angle.

i think i will also try to get the shop to make them sort of cone shaped...in other words, the opening size increases from front to rear. this should help reduce exhaust velocity slightly, and will hopefully allow the exhaust to blend better in the slip stream so that paint staining isn't a problem.

i will keep you advised.

mike
 

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Pathologic Opeler
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1,960 Posts
update... valve or "dump"

ok...nathan ..guy at muffler shop says he will put on a glass pack
at no charge..he offered...so i will let him try the glass pack

ok..gary..the guy selling the monza tips said " it will only take out raspiness..dont buy them"

here is the problem: i like the way the car sounds..but i can tell no one else does...i love to hear the engine pull as the carb opens up...

after the glass pack is added is their a way to put on a "cable valve to bypass the glass pack"..so i can have loud ..WHEN i leave my neighborhood...

these suburbanites have no sense of humor or fun!
 

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70's Opeler, back 4 more!
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Bucky,

Just caught this thread. Part of your noise is coming from opening up your pipe to two inches. It allows the sound waves to increase in size.

Somebody, like RallyBob, may want to jump in here, but when you reduce the back pressure, you may want to check your jetting.

Also, the header pipes you are looking to install, will probably add more sound to what you have there already.

Any others want to jump in on the affect of increasing exhaust pipe size, reducing back pressure, and air/fuel mixture?

or does it matter here?
 

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WOW! I can not believe how much more power there is on my gt after I redid the exhaust! it is like a night and day difference, there is actually power. It sweeps the tach like nothing, the wheels actually chirped when I tapped on the gas in second gear and I was already moving. I guess the old exhaust system was really stuffy, and cobbled there was a piece of a fan belt holding the muffler up and it was 1.5" over axel. Now it is 2" from the header to a 2 1/4" magnaflow muffler and 2 1/4" over axel to an ansa resonator with 4 resonated tips, the resonator is painted with high temp black paint and the muffler and pipe is painted with high temp aluminium color paint. It sounds GREAT and the total cost was around $75 with a used magnaflow (only about 500 miles on it)
 

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length

Length and diameter pertain to performance. theortically the longer the pipe the more torque you will produce. The correct way to determine proper length especially when working with various performance engines is to use a liquid parts marker and stripe down the side of a straight pipe (they make a stick just for this) where the marker ceases to burn off (after a performance run) this is how long the pipe should be to scavnege exhaust to the maximum degree. Whatever muffler design you end up deciding on should be mounted prior to this spot. exhaust should then be turned down and cut to be scavenged by passing airflow. This is a performance exhaust....for any type of performance engine with a modified engine. It works. (any longer pipe than this point, by the way it will be necessary for the engine to 'push" the exhaust out which, of course, kills horsepower)
 

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Mark, if I could amplify just a bit. A family friend, when I was a teen-ager, built the Buick engines for Mickey Thompson's brickyard (Indianapolis 500) attempt. He also built engines for the family's racing boats. I watched him one day tuning the exhaust stacks for one of the engines. He had 6 foot long exhaust pipes, painted white, bolted to the exhaust ports. Then ran the engine on his home built dyno to the RPM he wanted and after a bit shut down the engine. He showed me where the exhaust overlap pulses were on the individual pipes by having a ring of burnt paint around the them. He cut the pipes about a 1/4" before the burned ring. His reasoning was the exhaust was still flowing out of the pipe at that point and not being sucked back in by the valve overlap. It was interesting, that after he cut the pipes he gained about 50 horsepower at the same RPM. Also he cut the pipe ends at a 45 degree angle with the long end of the angle forward to the direction of travel. He explained it was a siphon effect that would help pull the exhuast out of the pipe. It's those little things that add up. :D
 

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Exactly

That is the procedure and my point. we are on the same page.. Esay procedure for 50 horses eh? Yes turning and cutting for the siphoning effect is imperative.
 

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On my Dodge van with the 340, I have Heddman headers, 2.5 in and out mufflers, and one 90 degree bend to exit the exhaust just in front and outside the rear wheels. I have the 2.5" 45 degree chrome exhaust tips, with the long tip forward just for the siphoning effect as I was informed those many years ago. I would like to do it on the GT but using the stock exhaust location doesn't permit it. When I do the monza, it will get the same treatment as the van. Gotta think an engine is nothing more than an air pump and anything to assist in moving the air in or out has gotta help. ;)
 

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I posted this before but without any pictures so this time I've got some photos. I fabricated the exhaust system on my car using 2 inch mandrel bent pipes going to a MagnaFlow 4"x 9" oval muffler, part number 11365. After the muffler I used 2 1/2 inch mandrel bent pipe over the axel to a 2-inch "U" with Monza Pacesetter tips out the back. Both tips are functional. I spliced into the stock down pipes right after they came together into one pipe. The system on my car is loud not obnoxiously so but I have a different cam, ported intake, larger carp and high compression pistons so I have always thought this had more to do with it then the muffler.

This past weekend a club member came over to my house and we fabricated the same system for his stock 73 GT and it was not loud at all, jump in here Roy and give your thoughts on it. The only exception is we used 2 1/4 inch over the axle. After doing the second GT I recommend the MagnaFlow muffler for the GT.

One thing that I wanted to make sure was that the exhaust pipes and mainly the muffler did not hang down too far under the car. In this picture you can see the muffler tucks up there nicely. I did have to remove the stock muffler mounting points and use standard hangers

Brian
 

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