3'' exhaust on the ms3?

[nig3]

anyone done it yet? does it make more power than 2.5''? Im making my own this weekend and was wondering anyone else has tried it and what the outcome was, thanks.

 

[bykeryder4life]

clearly it will, having less restriction after the turbo is good. I see you have a cs dp so making the rest of the exhaust 3" will complete the SYSTEM and allow you to feel the full potential of your dp as well. right now your 2.5" system is like a bottle neck for the flow coming from the 3"dp. get a full 3" exhaust and get a mani as well, then an inlet for your turbo and you will have a free flowing setup that will spool wayyyy fast.

 

[bykeryder4life]

i hope you are experienced in welding and exhaust systems if you are doing your own otherwise dont even try. tig weld it all, mandrel bend it all, full ss piping, and make as few bends as possible.....plus much more

 

[Captain KRM P5]

pretty much every aftermarket system is 3 inches. corksport is 80mm which is slightly larger than 3 inch.

 

[nig3]

Im using 3'' stainles steel all mandrel bent, i have my own welding equipment too, ive never made a custom exhaust before but have made a bunch of other crazy s*** with my welder, should'nt be hard. Im also gonna run it all the way back but still use the stock rear muffler section, it looks damn close to 3'' factory on the last section anyways, plus its good for the sleeper effect.

 

[nig3]

how much more power do you think i would gain from 2.5 to 3'' exhuast?

 

[jam_asian85]

it would be a substancial gain nothing to drastic but be prepared for some smoke seeing how you wont have any cats nor resinators. Installing a catch would be a plus while you're doing the exhaust, good luck

 

[bykeryder4life]

if you make an exhaust dont keep the rear muffler section make a new 3" section and get a new muffler thats 3" inlet and outlet. do it once and do it right. just make sure to tack weld it all first and make sure all the hangars are lined up and none of it will hit the heatshield and then go back and weld it all up. what kind of welder are you using? what materials have you welded before this?

 

[bykeryder4life]

are you making your own flanges or buying them? you will want some for ease of installation/removal if ever needed.

 

[YOUNGMP3]

I remember seeing this thread a while back and thought you would like to read it.
http://www.mazdas247.com/forum/showthread.php?t=67805

 

[nig3]

Ok here is what i made today, took me around 5 hours from start to finish, and i did this with jack and jack stands LOL... anyways dont make fun of my welding, i used these new stainless steel small rods and they were harder to weld with than usual. The exhaust is beautiful and line up perfectly with the stock rear muffler section. BTW you cant even take the exhaust off the car unless you cut it in half first, So I guess it was a perfect time to add the flange in the rear right before the rear suspension. I havent really had time to test it out other than a short ride down the street, really didnt seem much faster and its definatly louder. I can hear the turbo threw the exhaust now. I think i will eventually add a muffler somewhere in the mid section like the stock set up, so thats its alittle quieter. Also do you think i should reset my cobb ecu because it felt kinda weird when i drove it that short distance like it didnt spool as fast. I will drive it more tomorrow i think once the ecu learns the extra flow it should run great!

 

[aaronc7]

yeah reset the ecu..........honestly that's pretty cool you did it yourself, looks good

 

[FrequentFlyer]

Not bad. Get alittle better at it and you could make some money here.

 

[UHATEIT]

thats really good work man, even busted out he testpipe 2nd cat section too I see, very nice work man very lucky you have the tools for all that, turned out pretty nice! Hope it sounds sweet for you!

 

[CWPspeed3]

Impressive job, looks great to me, could you make some sound clips?

 

[bykeryder4life]

haha sorry but i cant keep myself from laughing at the welds its ok though what you should do in the future is practice with your materials(rods and piping and settings of your welder) before you do the real deal. what did you use to weld it all up?

 

[lil_red_wagon]

looks like mig welds. i think that you did pretty good for your first exhaust. they may be a little gorilla, but they are still pretty clean.

 

[Yoo Shin]

I guess it depends but dyno testing would be the best way to assess. Most of the gains from a full 3 inch system will be seen from a tune or when the turbo is upgraded.

It's interesting to see a STI with Stage II OTS map, dp & stock cbe vs. a 3" cbe will be 5-10whp max, where as an Evo8/9 with no EM, dp, & stock cbe vs a 3" cbe will be 15-25whp. So I guess it just depends. How much is the system costing you to make?

 

[nig3]

I used a stick welder, which is the most difficult and most time consuming way to weld something like this. All the materials cost me around $110. It was fun and plus i saved tons of money and actually got a decent quality exhaust system, much better than any muffler shop could do.