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Discussion Starter #1
Putting together a custom exhaust with high flow cat, resonator, y-pipe and magnaflow exhaust. Wanted to see what has been done or if I am treading virgin ground? Helpful responses only please!!
 

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The closest thing that has been done I believe is a custom modded 14 mazda 6 pace car at laguna seca that had a custom maganaflow system installed.

http://forum.mazda6club.com/mazda-6-3rd-generation-2013-present/263256-mazda6-pace-car-mazda-laguna-seca-raceway.html

as far as mainstream every system i know of is an axleback, corksport, racing beat, tanable and autoexe, which are all bolt-ons and need no modifications or welding. Maybe in the future there will be a kit but no company has tackled a full catback yet, use to complexity and demand, $$ i guess. plus our mazdas already have a "racing" 4-2-1 header that is very free flowing i heard, and just the whole system in general is not very restrictive to warrant a need for full catback.

and for laughs, straight pipe haha

https://www.youtube.com/watch?v=zh-jz17Dws0
 

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Discussion Starter #3
Thats the car that made me want to do a custom setup. Although I think a full 3' may be overkill.

The 4-2-1 headers are very good. I would not mess with them unless I was compelled to go crazy on a race setup. Ours headers look like medusa's hair, but they still are a million times better than a manifold setup. I am planning on leaving that in place and building the exhaust back from there.
 

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Discussion Starter #4
The closest thing that has been done I believe is a custom modded 14 mazda 6 pace car at laguna seca that had a custom maganaflow system installed.

http://forum.mazda6club.com/mazda-6-3rd-generation-2013-present/263256-mazda6-pace-car-mazda-laguna-seca-raceway.html

as far as mainstream every system i know of is an axleback, corksport, racing beat, tanable and autoexe, which are all bolt-ons and need no modifications or welding. Maybe in the future there will be a kit but no company has tackled a full catback yet, use to complexity and demand, $$ i guess. plus our mazdas already have a "racing" 4-2-1 header that is very free flowing i heard, and just the whole system in general is not very restrictive to warrant a need for full catback.

and for laughs, straight pipe haha

https://www.youtube.com/watch?v=zh-jz17Dws0

Also, I really want to get the part number on those brembo brakes.
 

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Discussion Starter #6
I just did a quick search and found this, man does it look pretty, and it will burn a hole in my wallet too if i get it haha

Brake Pads, Rotors, and Lines

i found it after browsing this thread

http://forum.mazda6club.com/newbie-section/283809-brembo-big-brakes-mazda-6-2014-a-4.html
At that price that will def be a ways out. I am sure it will be worth it when I do jump on them. My current rotors are tiny under 20" x 8.5" wheels. Oh, and th braking will be EPIC!!

:eek:fftopic: lol My bad
 

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Discussion Starter #7
Looks like the car comes stock with 2.5" from the headers. I am going to be doing a cat back 3" exhaust with no resonator and a flowmaster 40 series muffler. Will post clips when all done.
 

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Yes but more so because I'm curious to hear how it sounds. I did that with my miata and slapped on an RB axleback and it worked great!

Our cars are headers to single cat to a single resonator to exhaust, right?

Sent from AutoGuide.com Free App
 

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Discussion Starter #13
Correct. It's all 2.5" mandrel bent from the header. Pretty damn good for a stock exhaust
 

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wouldn't going 3" exhaust on a N/A 2.5L motor kill back pressure and probably end up losing power?
ahhh good ole back-pressure.....

This was a HUGE debate on LS1s way back when 1 7/8" primaries on headers and 102MM Fast intakes were brought into the equation then combined with a full dual 3" exhaust. Everyone argued it would lose low-end on a stock engine while gaining very minimal on the top end. Just a few years ago the back to back dyno experiment was finally done, turns out the gains were across the board in measurable territory with a nice peak gain and some extra grunt down low. A free flowing large exhaust and intake (unless total overkill, like say a 102MM on a stock low compression 1.8L 4 cyl LOL) isn't actually going to lose much of anything. Until you cross the threshold of the amount of air the engine can move, it's not going to hurt much if at all. Couple that with a hot high compression 2.5L 4 cyl... it moves some serious air, and it wants to move it FAST. Those hot air temps want to transfer to the cooler ambient as quickly as possible, and the header design on this car helps that occur.


From that underbody shot.. is that a cover we can re-use on the exhaust, or is it that the muffler? If the latter I would be wary of replacing it just based on aerodynamics :(
 

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jeez.. for what these aftermarket companies are charging they should mold the bottom pan of the stock muffler and make that a bolt-on option to the mufflers. I mean how hard would it be to weld up an extra bracket to bolt that plate to to maintain the factory aero? It's obvious the muffler is a big part of that :(.... I'll definitely be waiting until I can chop the factory muffler to pieces and re-use that bottom plate. The slight efficiency increase likely negates any MPG lost from the aero drop, but since my driving is almost exclusively highway also, I'll take every aero panel I can!
 

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Yeah, but reality is we'll never know if simply increasing from 2.5 to 3 will have any difference on hp or torque, better or worse, all else kept the same. 200hp is just so borderline between the two.

The real opportunity for gains is in swapping out the muffler for something lighter and more free flowing.

I will reference the following from Magnaflow's website as a reputable point of view which I relied on for selecting 2.5" for my custom axle back setup, as I was concerned with weight and ease of instl and wanting to err on the side of not loosing any torque without too much hp hit:
MagnaFlow Performance Exhaust - FAQ, Frequently Asked Questions

Don't be fooled! Bigger is not better! Many people think that having the biggest diameter pipe is the best way to make power.
Not true. Due to a variety of factors, extensive testing is required. We've dyno'd extensively and our systems yield optimum power increases. Some manufacturers claim even higher horsepower numbers....

Keep in mind that the goal is to improve exhaust flow. In most cases, just changing the restrictive OEM muffler and replacing it with the same size straight-through, Wide Open Performance MagnaFlow muffler will do the job.

To reduce additional backpressure, the OEM exhaust tubing can be replaced with mandrel-bent tubing of the same size or one size up from the OEM. As a general rule, you can enlarge the pipe diameter of your OEM exhaust system by 1/4 to 1/2-inch to increase your horsepower. However, any additional increase in pipe diameter is likely to decrease your performance; specifically, low end torque.
 
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