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Hello! I wanted to get some info. I have a 94 legacy wagon, non turbo. I've been contemplating doing a straight pipe from the catalytic converter back, and wanted to know if it would be worth it. My only goal is to get better sound out of it, and not affect the awesome gas mileage. This is my first subaru, and I just want a little more sound out of her! Thanks in advance

 

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By doing that you'll delete the resonators and it'll drone. Loud exhausts are fun for about 5 minutes, then they get really annoying. You spend your whole drive getting tinnitus and spotting cops so you don't get ticketed for an inordinately loud car. I put a lot of effort into keeping rusty mufflers on my subarus (except I gave up on my GL...), it baffles me (pun intended) why anyone would cut them off...

Edited by 987687
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The NA engines rely on certain amount of backpressure. If you run a straight pipe back, your MPG will tank and you'll find you are pressing the gas pedal further down to get up and moving from the loss of low-end torque.

 

If you want more sound, try running a 2.5" cat-back pipe and run a muffler designed for more noise, but still internally baffled (like a Flowmaster 50 series). If that's too loud or annoying after a week, unbolt that muffler and try running a Summit Racing turbo muffler http://www.summitracing.com/search/product-line/summit-racing-turbo-mufflers    (non welded casing as their welded variant is basically a generic Flowmaster 40 or 50 series) and you'll get a cleaner sound w/o being raspy or loosing low-end power. That muffler is a good muffler to drop weight (6 pounds vs. 45 pound stock muffler) and will probably free up 5-7 hp.

 

Running straight pipe on a turbo'd engine is different as the exhaust turbine alters the sound somewhat, and the decrease in back pressure actually aids turbo spool up, so it counteracts the NA's loss of back pressure as boost is earlier.

Edited by Bushwick
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The poor man's alternative would be remove the resonator and slip fit a straight pipe, then cut the muffler off and buy a 3" inlet/outlet Summit Racing Turbo muffler I linked above, and buy 2.25" to 2.5" adapter, then a 2.5" to 3" adapter, and jump your factory pipe to the 3" muffler size. Most (possibly all) muffler shops will NOT do this, and more than like they'd try and heat the pipe then clamp it to crush down if they were even willing (need a custom muffler shop, NOT a Midas or chain location) or better yet, do it yourself.

 

That will allow it to sound a littler louder as you'll have the 3" outlet on the muffler, but will still sound cleaner and MPG shouldn't tank.

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I put a Flowmaster on my 2001 Legacy Outback (I am not sure what series) and that is the only part of my exhaust that rattles. It is driving me INSANE. Does the shape of the muffler affect the sound that comes out of the exhaust? My car sounds throaty until it gets to the muffler, then it just sounds like a darn fart can :confused:

 

I bought a new header for mine for less than $130. Well worth it.

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I have a straight pipe on my '96, and by straight pipe I mean, cough, cough, no cats, but I do have a glasspack muffler to knock it down a bit, it's louder then frig, but I don't usually drive it long distances. I really haven't noticed any performance gains, or losses, seems pretty normal to me.

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I put a Flowmaster on my 2001 Legacy Outback (I am not sure what series) and that is the only part of my exhaust that rattles. It is driving me INSANE. Does the shape of the muffler affect the sound that comes out of the exhaust? My car sounds throaty until it gets to the muffler, then it just sounds like a darn fart can :confused:

 

Straight thru mufflers that are literally a straight shot from one end to the other w/o baffling, do little to limit noise. If you run a couple of them end to end on say a turbo engine, they can sometimes be manageable if you are not getting on it constantly.

 

Flowmaster, and similar mufflers rely on internal baffling, that deflects sound waves, has sound traps, etc. to give a unique sound, and with Flowmaster, they offer different "series" of them, with I think the lower the number, the more aggressive the tone, regardless if a cat in place or not. Summit Racing makes a welded case muffler that's apparently a copy of the 50 series or something in that realm after a patent for Flowmaster expired (this was told to me, I assume it was true). Anyhow, I ran 2 of those on my Mark VIII (4.6L DOHC) and they were obnoxious. Those lasted about a week before getting cut off. If you have one of those "look at me" trucks, they are perfect. A daily driver car? No.

 

If you want increased flow, a clean sound with a minute amount of clean aggression when stomping on it, and 35-45 pound weight loss, give one of those Summit Racing turbo mufflers a try. I personally love them, and they can get meaner behind a performance V8 engine while still being quiet for cruising. On 4 cylinder cars with cats in place, they give a really clean tone w/o the obnoxious rasp or cackle. They typically run $35 each, so it's a cheap experiment to see if you like the note. Can try googling them. This link: 

 the 1st mufflers are the turbo variants, the second ones in the video are welded case Flowmaster knock-offs. The welded ones are MUCH louder in person as that's what I ran with cats.

 

Also, pipe diameter outlet affects sound as does a dual outlet. If you have a 2.5" outlet, that'll be louder than a 1 7/8" outlet. Entire pipe diameter from cat back has an effect on sound as well.

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A glasspack all the way at the end can make for some interesting sounds.

Using a smallish one will add just a touch of back pressure but since it's short and straight through it flows a little better than stock.

 

Buddy had a plymouth horizon manual, one of those little 2.2L boxes.

 

When the exhaust fell apart he had me put a 90 elbow just after the cat and tun the pipe out just ahead of the drivers side rear wheel. Sounded nice, and not too loud when not flooring it, and was nicely waspish revving it up floored.

($$ was the only real driver on that one...)

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^ I ran dual dumps (Summit Racing Turbo mufflers with 90 degree turn downs) just ahead of the rear axle on my 79' Mustang that had a warmed over 306 with RV cam, 10:1, small carb, etc. That thing screamed and had a truly unique sound. The unibody acts as a sound trap as it reverberates off the pavement. Gotta watch though as it's an easy way to kill yourself at a red light, but man it's a nice sound.

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