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Discussion Starter · #1 ·
So I bought a 2012 speed3 cat back exhaust from craigslist for 200 bucks. mint condition, maybe 2000 miles on it. bolted up the axle back portion, sounds great. now I want the midpipe on there, just to see what it sounds like. im not gonna cut anything off so I can go stock again if need be.

I got underneath and the midpipes both have the same bends and hanger points, only I need to make up about 13.5 inches to get to the next flange and avoid cutting. heres the problem. ive searched high and low all week and cant find out the info I need about flange sizes. the speed3 midpipe front flange is big. I want to find the matching flange for it so I can delete the cat and fab up a pipe to fill the gap. I measured the circumference of the midpipe and did some math to get a rough diameter of about 2.5 inches. I wont know the diameter of the stock pipe foward of the cat at the flange until I pull that rusted crap outta there.

my plan is to hose the bolts with some pb blaster when I get home from work in the morning, sleep, then try and break em loose. with the cat pulled out, I can mount up the speed3 midpipe and get a better measurement for the pipe to build. after getting the measurement, im taking both pipes to a muffler shop to get each size flange needed and some pipe.

long story short, im deleting the second cat to install a speed3 cat back exhaust. expect pictures, measurements and sizes/dimensions to follow. im very frustrated with the lack of info out there. its prolly not worth the hassle, but I like to work on projects. I want to get the info out there for anyone else who has the midpipe collecting dust like me. :)

stay tuned....
 

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Discussion Starter · #2 ·
Havent had a chance to work on it yet, slept in too late yesterday and the weather is not cooperating. Hopefully tomorrow is the day.

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Discussion Starter · #3 ·
Okay, so I made some progress. Got the bolts broken loose, midpipe with 2nd cat out, then speed3 midpipe on. Theres about 13.5" from the new midpipe to the flex pipe forward of where the 2nd cat was. Went to Top Value Muffler near me and the guy helping me was super cool. Cut me some 2.25" pipe and gave me 2 flanges and 2 gaskets for 25 bucks. The new flange joining the speed3 midpipe will need to be wallowed out a bit, but it should work just fine. Hopefully I will have some time at work tomorrow to weld the pipe up, then get it installed. Here are a couple pics to show the difference between mz3 midpipe with cat and speed3 midpipe with extra pipe.

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Discussion Starter · #4 ·
Making progress. Got our best welder here at work fabbing up the pipe, dont want to do it myself and make it look like bird poop...but its coming along well....should be able to get her on the car tomorrow and put up some before and after sound clips.

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Discussion Starter · #5 ·
Update:

Pipe is made. Gotta clean up the welds a bit. The flange I had to mate to the midpipe wouldnt work, so we made one out of 1/4 inch steel plate. Went to autozone and the nice guys there dug through stock to find me a gasket to fit, rather than order one and wait for the mail. Its for a catalytic converter on GMs i think. Ironic seeing as i need it for deleting my 2nd cat.. Also got some copper rtv just in case. All thats left is to find some bolts here at work and get this pig on there. Im sure the right size flange can be ordered from mazda to do things properly, but im happy with fabbing stuff up. :)
If anyone needs a gasket to work, this one works for a flush mate flange. Stay tuned and thanks for patiently following!

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Discussion Starter · #9 ·

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Discussion Starter · #10 ·
Cleaned up some rough edges and hooked it up with the fel pro gasket. Nice flush mating, no issues. Hit it with the pneumatic wire wheel to shine it up a bit. Cant wait to put it on today after I wake up! This is my first custom mod on my car, so im pretty pumped. Ill figure out uploading the video clips for before and after and get them up tomorrow night if possible (thursday). Maybe this weekend I can get the whole system pulled out and painted with some exhaust paint for protection.

Can anyone suggest a good product for that? Id appreciate anything you guys can vouch for!

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Discussion Starter · #11 ·
So im an idiot. Didnt take the flange angle into account. Gotta cut the front flange off the new pipe and angle it about 20 degrees, then reweld it. I was pretty pissed today before work when I thought it was just about on. Oh well, live and learn, just a bit more time before its finally done.

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Discussion Starter · #12 ·
Finally got it done right and put on. Had to cut the end off, reposition it to have the right angle, then reweld it. Got it hooked up no problem. It definitely sounds a bit raspy, kinda makes me miss the lower tone. It turns heads if i get on it, but its not too loud/obnoxious when driving normally.I will get my before and after vids linked up here in a min.

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Discussion Starter · #13 · (Edited)

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cat delete

09 speed 3..exhaust is stock for now. about to delete mid pipe and replace with catless straight pipe, mechanic (close family friend) said he would just weld a straight pipe in. would i need a trick kit or c02 jumper in order to not throw and cel lights?
 

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Discussion Starter · #15 ·
Not sure on a gen1 speed. If it is an unmonitored cat (no O2 sensor) then u shouldnt pop a cel. Dont quote me tho.

Also, is it the cat u are cutting out or the resonator?

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09 speed 3..exhaust is stock for now. about to delete mid pipe and replace with catless straight pipe, mechanic (close family friend) said he would just weld a straight pipe in. would i need a trick kit or c02 jumper in order to not throw and cel lights?
CEL won't come on the Racepipe/Midpipe isn't monitored by the ECU, it won't even know it's gone.
 

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Discussion Starter · #17 ·
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