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Bros op on muff.
I'm finally getting around to upgrading the exhaust system on my nb and have some questions.
I am sticking with my 2.5in begi dp, but am having a friend at an exhaust shop build the rest of the system for me. The cat is going bye-bye as well as the resonator, and I am planning on getting rid of the lower half of the begi dp that contains the flexpipe and flange and running a slip fit all the way back to the muffler instead. I want a quiet setup because with the 4.30 rear end I spend a lot of time above 4k rpm in cruise and I don't want to go deaf. Will I be happy with a 2.5in system back to a large magnaflow muffler or am I leaving power on the table without going 3in? Turbo is a 2854 and I run 15psi. Also, what is the largest magnaflow that will fit under my nb without modification? |
3" or you're leaving power on table.
5x11x22 iirc |
5x11x22 or die by fire.
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Should I go right from the 2.5in dp to 3in or what? Also who's got he cheapest price on magnaflows?
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yes. either have the cat step up to a 3" outlet, or make the exhaust bolt up to the 2.5" DP and step up to 3" the rest of the way.
performancepeddler.com will have the best prices if you email them for a better price (see site) but all vendors will sell mangaflow mufflers are exactly the same price advertised. |
4" exhaust or bust
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4"? I may need you to fly to Detroit so I can take advantage of your skills with a sawzall.:party:
Ok, so have him come off the dp with a short taper up to 3", back to a 5x11x22" magnaflow with a 3" opening, profit? Ordering muffler tonight, what are you gays using for a tailpipe? Thanks:bigtu: |
we use a pipe for a tail pipe
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Ok, I ordered the 5x11x22 magnaflow last night. Best deal I found was $101 shipped off amazon, it should be here early next week.
:party: |
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My muffler came in the mail today. I ordered the magnaflow #12579 with 3" in/out (5x11x22). It's freakin huge!
I thought I was getting a straight through design but it actually forks off into two chambers and then back to one at the exit. I hope I got the right one? My car is going under the knife Wednesday morning, I'll update when I get her home. |
Post pics. I don't think you got the right one. The right one is straight through
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Originally Posted by flounder
(Post 907135)
My muffler came in the mail today. I ordered the magnaflow #12579 with 3" in/out (5x11x22). It's freakin huge!
I thought I was getting a straight through design but it actually forks off into two chambers and the back to one at the exit. I hope I got the right one? My car is going under the knife Wednesday morning, I'll update when I get her home. My magnaflow is straight all the way. I think you got the wrong one. |
What part number is yours?
1000th post! :party: |
if its chambered, its weaksous and you should return it
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that's not right.
here's mine" straight through: [img]www.boostedmiata.com/gallery2/d/11084-2/parts+004.jpg[/img] |
ololoollololololloolololollo brainy can't post pics.
edit: ahahghehwhahwhas your shits broken. |
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Huh, no boostedmiata.com stuff works for me, "Problem loading page".
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pretty sure it's 12578. lol. missed it by a digit sucka!
http://www.magnaflow.com/02product/d...rtnumber=12578 http://www.magnaflow.com/02product/d...rtnumber=12579 note the core size. the 12579 has a "dual 2.5" 12578 is 3". you're welcome! |
Originally Posted by curly
(Post 907219)
ololoollololololloolololollo brainy can't post pics.
edit: ahahghehwhahwhas your shits broken. was on the mobile site, didn't parse my img tags... weird. |
Whos hacking your exhaust? I hope it's a reputable place or IT WILL RATTLE EVERYWHERE.
On a side note, you might be able to return it on the sellers dime if this is the same listing. "Magnaflow Stainless Steel 3 inch Oval Muffler is designed to reduce the amount of noise emitted by the exhaust system and to increase engine efficiency. It is manufactured from stainless steel and comes with an oval body of 18 inches with an overall length of 24 inches. This muffler offers a single inlet and outlet measuring 3 inches that is positioned in the center. It features a straight-through perforated stainless steel core as well as an acoustical fiber fill and is backed by lifetime warranty." |
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I don't like the one you got. It looks chambered. I didn't even know magnaflow made those, unless for trucks in the XL series.
What part number does the box say? because this is what yours should look like*: https://www.miataturbo.net/attachmen...ine=1343136357 *the one I posted before has an offset outlet, the above is center/center. |
Originally Posted by Braineack
(Post 907263)
What part number does the box say?
? |
interesting.
This is something unlike most Magnaflow and looks to be a new part: I have a Magnaflow single 3" with a 12579 muffler mandrel system in the corner for the day TOG headers go in... The 12579 is pretty unique from all the other Magnaflows in the 5x11 case... It is a center 3" inlet that splits off inside to dual 2.5" pipes, and comes back out a single 3" center... Magnaflow designed this muffler especially for the new Vortec V8 trucks due to the bottom end loss, and resonance issues with the 4.8, and 5.3 ... I personally don't think the Flowmaster 70 will flow what the TOG headers can, so a straight through muffler is in order... If you want more info, PM me off the list, and we can talk... There are many guys on this board who consulted me on exhaust, and have come through with flowers... So, take it for what it's worth... Magnaflow has confirmed, the 12579 muffler was designed for our 5.3L engine. It is louder than stock (by maybe 10-15db's, my best guess), but definitely quieter than the 12589 (by at least 10-15db's). The 12579 has a nice sound, but I doubt you will be able to tell how loud it is to the outside world unless you go WOT in a tunnel or a parking garage or something. I've driven around town with my windows down and I can't really hear it that much. ON THE OTHER HAND, the 12589 has an awesome louder sound that you can definitely hear, especially when you drive under freeway overpasses. It leaves no doubt that you've done a muffler mod to your AV, and it really sounds great (sort of sounds like a cigar speedboat exhaust). From a pure exhaust note standpoint, I'd vote for the 12589 (the AV also sounds less strained under WOT with the 12589, whereas the 12579 is sort of higher pitched and makes other drivers think you're winding up your engine to race or get ahead of them -- a layman's observation). |
Damnit. How bad can it be to run this instead? Being a 3" exhaust, I can't imagine even with this small of a restriction, I'll have a problem with backpressure?
I got it off of amazon after searching for 5x11x22 3", Plus someone else on mt.net said they are using this P#. |
If I had it, I'd still run it. I don't believe it's going to measureably impact performance over the single core.
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Hell, maybe it'll help low end torque? lol
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I predict your friend at the exhaust shop will use crush bent pipes to make your exhaust. The tightness of the bends required to fit that huge muffler back there will mean the inside of the pipe is pretty tiny after it is crushed, so the muffler won't be your problem. I'd say it'd flow about the same as a 2.5" system orientated the same way.
I go with the 5x8x18 muffler. Plenty quiet and the muffler fits at an angle so the bends are much straighter, especially if you are not using mandrel bends. https://www.miataturbo.net/attachmen...ine=1343140385 https://www.miataturbo.net/attachmen...ine=1343140385 Now if my new setup is too loud or drone-y, then I will definitely consider that 'new' magnaflow, I had no idea they made something like that. Of course, with tight radius mandrel sections. The old Edelbrock stainless mufflers were designed like that and I searched for a while for them back when I made my exhaust but are no longer made. EDIT: I use 18" long muffler, not 14. |
you can fit the 5x11x22 in the same fashion as above. in fact, I'd prefer that over mine with my crazy ? bend.
I just cant remember who did it to post pics. |
Oh wow, so this could potentially be a BETTER solution for people that want max flow with minimal sound? Since its still technically "straight through" I don't see it choking up too much more than the original, but I may be way wrong.
I know on the Borla Hush for the scoobs, it goes from 3" in to 2 2.5" outs and is a bit more restrictive than your average straight through 3", but I'd gladly give up 5-10hp for a SUPER quiet exhaust. Is there a cutout/diagram of this new one? *EDIT: just saw the uploaded pics Definitely looks like it will be significantly more restrictive. I'd still run it though. Looks like it will be ultra quiet. |
Pics pretty much show everything you need.
3" pipe splits to (2) 2.5" preferated cores, then back to a 3" outlet. I'm sure it can flow more CFM than you can afford. |
see edit:fawk:
I was really hoping it would be a smooth Y transition instead of a T poop |
I would too, but I doubt it matters.
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Originally Posted by 18psi
(Post 907297)
Is there a cutout/diagram of this new one? *EDIT: just saw the uploaded pics Definitely looks like it will be significantly more restrictive. I'd still run it though. Looks like it will be ultra quiet.
Originally Posted by 18psi
(Post 907301)
see edit:fawk:
I was really hoping it would be a smooth Y transition instead of a T poop |
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Ahh ok, not really a "T" but poor manufacturing of the Y. Yeah, i'd say that's maybe 3 hp.
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U sure it looks like that or its not a square split?
Y U NO RUN FLOWMASTER 40? |
When you get this sucker on there, we need GOOD SOUND CLIPS. Seriously. Please don't let us down.
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This good for ya?
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Originally Posted by triple88a
(Post 907356)
U sure it looks like that or its not a square split?
Y U NO RUN FLOWMASTER 40? flowmaster 40 : https://www.miataturbo.net/attachmen...ine=1343149723 chambered mufflers don't use perforations and sound-deadening material. The use noise-canceling tech. |
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Originally Posted by triple88a
(Post 907356)
U sure it looks like that or its not a square split?
Y U NO RUN FLOWMASTER 40? flowmaster 40 : https://www.miataturbo.net/attachmen...ine=1343149728 chambered mufflers don't use perforations and sound-deadening material. They use noise-canceling tech. It's like trying to gag your mr. slave by putting him in a large room with partions, intead of just using a sock. |
the FM40 is garbage. so lets move along:
I'm not so sure it would be a mere 3hp lost from the split being the way it is - the exhaust gas is traveling directly into a wall, then being pushed to the side, going through the 2 passages, then hitting another wall, then being pushed against one another, and only then out the end. Does everyone really think that's "only" going to affect it 3hp worth? Or am I just overthinking this in terms of flow and underthinking in terms of overall backpressure? |
Partions? Brainie you been reading too many of Fae's broken posts :)
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Hmm ok. The first wall is not flat but pressed into a sorta V, like they do to their Y and X pipe exhausts. You can sorta see the opposite wall where the perforations are looks to be not flat too. The only icky area is where the straight preferatored tube mates to the pressed Y.
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Oh they'll be vids... Quailty may vary.:rofl:
I can't wait to show up with this huge muff at the shop tomorrow, my friends gonna slap me. Hopefully I'll be driving home with this installed by tomorrow at 6pm. |
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Originally Posted by 18psi
(Post 907368)
I'm not so sure it would be a mere 3hp lost from the split being the way it is - the exhaust gas is traveling directly into a wall, then being pushed to the side, going through the 2 passages, then hitting another wall, then being pushed against one another, and only then out the end. Does everyone really think that's "only" going to affect it 3hp worth?
Or am I just overthinking this in terms of flow and underthinking in terms of overall backpressure? yeah, and you forgort about thermal/fluid dynamics, pressure differentials, and all that jazz. https://www.miataturbo.net/attachmen...1&d=1343152570 |
:makeout:
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I like to think of it as 2.5"+2.5"=5" of glory flow.:rofl:
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Actually it's 3.536" of glory flow, but we get it.
EDIT: actually-actually it's probably something different taking into account whatever flows going to stick to the walls. I don't want to look up those equations. |
It was a joke Tim.;)
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It's really quiet.
How do I add a sound clip?:noob: |
where's the dyno? w/ & w/out. it's been a whole day. we're all tired of waiting! I have the straight one not the bi one and it's pretty quiet. the bi one must be super quiet.
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Much like mr. Sawzall, I don't have a dyno sheet.
It is whisper quiet from idle to redline, all I hear is the turbo spool up and the bov. It's spooky. The turbo spools up much faster, and hits 15psi about 500rpm sooner too. Seat of the pants dyno feels like at least a 25hp gain and it still needs to be retuned. |
quite is awesome. upload video to youtube.
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Sorry for the long delay with the vids but I've been working my ass off all week (65hrs by tomorrow).
I actually had some other questions about recording sound in the miata. I was watching brains muffler vid and was wondering where you had the mic at? I'll basically be making my vid with an android, so I'm sure it will suck balls but I'm gonna try my best. BTW this exhaust really woke up the car. I read a lot about how much a free flowing exhaust would help on a turbo car but jesus christ! I've been working on the tune and this thing pulls like a freight train from 3.5k to redline. I swear I hear the tires chirp on the 3-4 upshift. I really need to get some dyno time scheduled and source a 3.9 diff at least. I'm off on Sunday, so I should get the vid up sometime soon. |
i use a dslr and it's mounted on my roll bar.
just make sure to turn down the volume or your stereo or we not be be able to hear it: |
Scott, you are the coolest mother fucker on earth.
How do you get all that thump? It sounds great. |
subwoofer.
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Originally Posted by braineack
(Post 908074)
quite is awesome. Upload video to youtube.
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Originally Posted by Braineack
(Post 908954)
subwoofer.
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