Hey guys, I have been trying to get my 74 Duster on the road again and I am finally coming to the exhaust stage (maybe that should read exhausted...) I haven't really been around long enough to know what effect too large of an exhaust can have, although on the other hand it doesnt take an idiot to figure out what too small of an exhaust can do. The engine is a rebuilt 225 with ~8.5-9to1 compression, Erson 270 cam, ported head, Offy 4bbl\390 Holley carb with Mopar 6to1 headers. I was thinking a 2 1\2 inch single exhaust would be ok but I dont want to go buy the piping and find out that wasnt the best choice. I am looking for an exhaust that will give the best performance and best sound. And speaking of sound, do you guys have any recommendations for mufflers? I want a mean sound with out too much raspy note. I was leaning towards a Flowmaster 40 series. Ill take any recommendations, thanks for the help guys.

--Nick

P.S. I haven't been involved in the Slant Six community much because of school and lack of time but I seemed to notice Slantsix.com is down and out.... anyone know what happened?

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Just Another Mopar Fanatic... Nick

I'm thinking that 2 1/2 pipe to the muffler would be more than adequate for a performance 225. Maybe 2 or 2 1/4 inch after the muffler (pressure drop) for ease of installation over the rear axle housing. I bought a "Heart Throb" muffler from J. C. Whitney for an old V8 Wagon I own. It has a nice rumble, civilized sound, but doesn't drone. Pretty well built, but not the cheapest. I don't know how that will sound with the /6, but I know I'm getting tired of the sound of rushing air when I mash down on my stocker.

Velocity Series Performance Welded Muffler - 5-1/2" x 11" Oval (14" long body, 19" long overall) 2-1/2" Inlet (Center); 2-1/2" Outlet (Offset) ZX283036 Each $60.99

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'63 Valiant V200 Convertible
225 Aluminum Block

2.5 is what I was thinking. I was considering duels, but I wasnt sure exactly how I would run the pipes from the collector... Instead I think a 2.5in pipe into a Flowmaster\Magnaflow\Other muffler and then dump right before the axle is what i want to do, its simple, easy, and easily changed if I want something else.
Thanks for the input guys.

--Nick

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Just Another Mopar Fanatic... Nick

Beautiful convertible Pat. I love it! On the exhaust issue, just be aware that it is the section after the muffler that booms, and this is a function of diameter and length. With these later A bodies, a 2.5" exhaust will definately boom at highway RPM if taken all the way to the bumper. 2.25 will still boom. When I had a stock 225, and a 2.5" single exhaust, my wife really did not want to take this car on the highway if we were travelling any distance.

I am convinced that Mopar used the smallish 1.75 rear exhaust size to control that boom. I have no mufflers on my car, and it is definately loud, but it does not "boom" since the length of the resonant pipe is full length and not just the section from the muffler to the bumper in length. The turbo controls the exhaust volume some, but I have been considering putting glass packs, or some other through design in there. But, if I do that, it will introduce the dreaded "boom" potential, which in the end might seem louder.

Sam

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I personally prefer a Magnaflow to a Flowmaster. Performance is just as good, and the exhaust note is not obnoxious like a Flowmaster. Magnaflow will last longer too. However, I think you will find any high flow will become tedious without a tailpipe to the rear bumper.

.com just kinda went into suspended animation last fall. No one really knows why.

http://www.slantsix.com/cgi-bin/Ultimat ... tion=intro

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Official Cookie and Mater Tormentor.

That sucks about .com... lots of good topics over there...

Anyways, I think I am gonna go with the the Magnaflow. I have had a couple cars and trucks come in to my shop lately and I have paid extra attention to how the different mufflers have sounded and I like Magnaflow's tone. Thanks for the input guys.

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Just Another Mopar Fanatic... Nick

Right back at ya Sam. It's such a "cool" factor to do the serious EFI/Turbo work you've done on your /6 when a lot a of folks would not have been able to resist the temptation to just install a V8. I hope I get a chance to see your set-up at some kind of event this summer.

Yet another turbo plus is the natural exhaust noise reduction factor. The SRT-4 Neon doesn't use mufflers either.

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'63 Valiant V200 Convertible
225 Aluminum Block

Not sure where the suggestions for 2½" headpipe are coming from, but that is needlessly/pointlessly large and a real nuisance to snake around the obstacles in and around the engine bay, not to mention getting a good and durable seal at the headpipe-to-manifold flange. Remember, the manifold outlet is 2" diameter. A 2¼" headpipe is a better choice than a 2½".

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Dan he is going to be using 6 into 1 headers, his collector will be 2 1/2" I believe that is where the 2 1/2" pipe idea came from. I am running a single 2 1/2" pipe from my clifford shorties (for the same reason) to my 2 1/4" in and out Cherry Bomb Turbo muffler. then 2 1/4" pipe out the back.

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Ah! That 'splains it.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.