Poor man's Exhaust (Removing Cats)

[Smiley2010]

Hi guys,

I've been looking at the Corksport/Borla exhausts for months now and so far I am not sure if I am totally sold on either of them. I'm in Vacnouver, BC so I'd have to pay duty on any parts from the states, increasing the cost of the catback/axleback systems. So I am currently considering putting a straight pipe with the stock exhaust systems in place. This would probably result in one of the cats being removed (this will be ok since I don't have to get it aircared for atleast another 4~5 yrs.)

My question is... has anyone done this with their new 2.5L 2010 M3?

I'm just wondering how much of a difference in sound I can expect with this. I've got a decent muffler shop that'll do this pretty cheap. I'd like a deep sound from the exhaust system that is relatively quiet below 3k rpm. If it gets loud after that its fine but I'd rather not get annoyed by booming exhuast noises while I'm on the freeway!

I'd really like any input!

 

[Super Unique]

removing the cats is a bad idea. It will drone like crazy at highway speeds, and is illegal anyways. It will do NOTHING for performance, and make it sound like a piece of crap.

 

[XspeedyD]

removing the cats is a bad idea. It will drone like crazy at highway speeds, and is illegal anyways. It will do NOTHING for performance, and make it sound like a piece of crap.

ummm, k. i put in a test pipe for the second cat on my MS3. cats are somewhat restrictive so its going to do something, but very minimal at that. mine doesn't drone much more than stock and definitally increased the sound output a lil bit. we do illegal things all the time, o well.

 

[Aetherfury]

and is illegal anyways.

It's illegal to exceed the posted speed limit...

It creates decent gains for the Speed3, but I don't know about the regular 3.

With that being said, on a non-turbo motor you need some of those bends and just making something free-flowing doesn't just equal HP gains (ask the S2000 guys...)

I would save up and get a tested cat-back exhaust.

 

[Super Unique]

The practical difference between a high flow cat vs. test pipe is negligible at best. MAYBE 2HP if your lucky. Is it worth 2HP to be kind to the environment and air we all breath, not to mention being able to pass emissions tests, and not worry about big fines? I would think so.

 

[Caedmon7777]

removing the cats is a bad idea. It will drone like crazy at highway speeds, and is illegal anyways. It will do NOTHING for performance, and make it sound like a piece of crap.

I had a 2000 Protege DX before I had my 2010 Mazdaspeed 3. I am telling you from personal experience that the exhaust is going to dive you nuts. I got the Bosal catback exhaust for my Protege and it sounded sweet when I first installed it. Then when the exhaust actually broke in, the exhaust sounded like just another ricer. Japanese N/A cars, for the most part does not sound good with an exhaust. I would take that money and invest it in some sound equipment IMO.

 

[Maz94Protege]

Have you seen the sound clips and the dyno-pulls on Youtube of the Borla and CS exhausts? I prefer the CS, it doesnt seem like it droans as much and has a nice tone plus from the vids its quieter.

 

[Smiley2010]

Have you seen the sound clips and the dyno-pulls on Youtube of the Borla and CS exhausts? I prefer the CS, it doesnt seem like it droans as much and has a nice tone plus from the vids its quieter.

Yeah, I did some more research and I don't think the power gains (if there are any) and the sound difference is worth it to put in a race pipe.

I am still waiting for the catback (hopefully) version of the Borla. I looooooved the sound of it in the previous gen Mazda 3's and the deep rumble is what I want. I am not sold on the Corksport version however... I've seen all the youtube vids for the catback system from them and in some it sounds like it isn't much of a difference in sound and in some it sounds very loud in the car...

Only thing about waiting for the borla is that I read somewhere that they might go with an axle back b/c their catback system didn't really produce much of a power gain... We'll have to wait and see I guess...

Thnx for all the input though, appreciate it!

 

[XspeedyD]

custom exhaust with magnaflow muffler, you won't regret that and it will probably be pretty cheap just go to a solid shop.

 

[coololddude]

Why not just punch a bunch of holes in your muffler with a screwdriver. THAT would save you a lot of money!!

 

[Smiley2010]

I got a universal Magnaflow muffler to do a straight up replacement of the stock muffler. ALL stock piping/tips for now. Cost me 250$ with parts/installation.

Car definitely sounds better. Deeper tone in the exhaust and louder at WOT. During regular speeds/cruise no drone and not much different than stock. I am going back to the shop to have the resonator removed. I've decided against the cat removal since I don't think its worth it. Hoping the resonator delete wont create TOO much of a drone but I'm expecting there to be some.

Hopefully it'll work out

 

[MS3 GT]

I believe it's the resonator that makes drone noise not cats!!!

 

[gprestonmoto]

Damn you guys sure do talk s*** to eachother. I like the CS exhaust, but I wouldn't buy Borla. You can do like me if you want, step outside the box and get a Racing Beat catback.

 

[skatethesea]

Before I got my exhaust I had a friend cut the resonators out and weld in a straight pie for $50. It was a good change in sound. And anything is worth a $50 try when it comes to modding.