Exhaust

[Chris_uk]

Hey guys

Went to the custom exhaust shop today and got it up on the ramp for some measurements, and ended up discovering that I actually don't have a 2nd cat on my exhaust, I have the 1 monitored cat, then pipe comes down from there into resonator(silencer) then continues all the way to the back box, is it because its the older face with the higher emissions compared to the facelift version? I know mazda made a few tweeks with the facelift model for emissions etc.

Just wondering as I don't want to get this exhaust made up only to discover im going to gain no power if im wrong about the cat lol

Chris

 

[blam2526]

Pictures, an what size diameter is it stock should be 2 1/4, upgrading the size? An what type of piping, miled steel or stainless. Resonator does drop preformance slightly, but morely there for sound. Just make sure u can run straight pipes but add the mufflers unless u want tickets an emmision, an abonious noise

 

[kwaits92]

Someone correct me if I'm wrong but there was much debate as to if the second cat was a cat or a resonator. And it turned out to be an unmonitored cat. My unmonitored cat is located just about under the front seats. I tried to get it cut out and the shop refused too.

 

[jasyatz]

There was just an article in Car and Driver about this exact topic. Variences in design of certain components for various parts of the world. It could very well be than in your neck of the woods, a secondary "scrub" cat was not required and as a measure to reduce build costs, subsequently not installed.

A pic would help, as the resonator could be mistaken as a cat and vise versa.

 

[jasyatz]

Someone correct me if I'm wrong but there was much debate as to if the second cat was a cat or a resonator. And it turned out to be an unmonitored cat. My unmonitored cat is located just about under the front seats. I tried to get it cut out and the shop refused too.

you could always cut it out yourself and go there with a leaking exhaust and ask them to bridge the gap with a section of pipe.

I've advised people to do that if they really want to eliminate cats as it is against the law in NJ to remove, modify or disable factory installed emissions or safety systems.

Jeff

 

[02semiata]

My new catback.

http://s875.photobucket.com/user/AWH_bucket/media/Mazda 2/DSC_1791_zps9c895668.jpg.html

 

[Andres3165]

My new catback.

http://s875.photobucket.com/user/AWH_bucket/media/Mazda 2/DSC_1791_zps9c895668.jpg.html

Andy Hollis' car?

Andres

 

[02semiata]

Andy Hollis' car?

Andres

That is correct. Andy had it for sale and I jumped on it. I was to lazy to post pictures of his cat back on my car haha.

 

[Andres3165]

Good for you, what did you do with the cat? Do you know how much your version weights ?
Wondering who bought the header.

Andres

 

[02semiata]

Good for you, what did you do with the cat?
Wondering who bought the header.

Andres

The cat is part of the stock exhaust and the whole stock exhaust is in my garage lol. Not sure about the header but from what I hear I am not missing out on much. He did recommend the one you sell but to be honest I am just going to keep the header stock

 

[Andres3165]

The cat is part of the stock exhaust and the whole stock exhaust is in my garage lol. Not sure about the header but from what I hear I am not missing out on much. He did recommend the one you sell but to be honest I am just going to keep the header stock

I meant the cat on Andy's set up. I hope you can Dyno your car with the new exhaust. T he factory header is very good.

Andres

 

[02semiata]

I meant the cat on Andy's set up. I hope you can Dyno your car with the new exhaust. T he factory header is very good.

Andres

There is no cat..... Just a burns muffler.

 

[Andy Hollis]

The long-tube header and the Magnaflow cat that goes with it went to an autocrosser in New Mexico. The dyno chart below (as seen in GRM) is between the header/magnaflow cat/Burns muffler and my original catback that Joe has (OE catted manifold, custom downpipe, and the same Burns muffler). The OE catted manifold is quite good. It really surprised me. The cat inside flows quite well, but the short runners put more of an emphasis on high-end power rather than mid-range punch. My long-tube header shifted the power band down some, giving up a touch of top-end for some more mid-range. But it was not a huge difference.

You can also see why raising the rev limiter helps. The power does not drop that fast above the standard 6300 rpm redline, so shifting well above the peak keeps your "area under the curve" higher.

This comparison was done with the Dynotronics tune and an Injecn CAI installed for both iterations, done one day apart with same weather.

 

[Andy Hollis]

There is no cat..... Just a burns muffler.

Just to be clear...there is a cat. It's the one in the OE manifold. The second cat and resonator are replaced by my shortie catback with the Burns.

 

[02semiata]

Andy what month GRM is this mazda 2 build in ? So with a injen intake your catback and a tune I should be around 100whp ? Man that is a lot of power haha I kid I kid

 

[CRG Racer24]

I think the biggest downfall of the stock header is the weird / tight angle that it has, I guess at the collector, just before the flange to connect to the rest of the exhaust. If that was cut off and made a smoother transition, and possibly if the cat was punched out, I wonder what that would do for the performance of the stock manifold?

 

[Andy Hollis]

Andy what month GRM is this mazda 2 build in ? So with a injen intake your catback and a tune I should be around 100whp ? Man that is a lot of power haha I kid I kid

104 actually, but who's counting?

Dynos are simply tools for comparisons. The absolute #'s aren't important. It's way too easy for things like gearing, wheels/tires, and especially weather to alter the overall #"s from day to day, or car to car.

 

[Andres3165]

Just to be clear...there is a cat. It's the one in the OE manifold. The second cat and resonator are replaced by my shortie catback with the Burns.

Was your cat metallic? I mean the element.

Andres

 

[Chris_uk]

Im sorry but never thought to get a picture of it lol, i'm kind of hoping maybe a few people can post pictures of theirs, I can tell you for certain what it looked like though, it was kind of rectangle shaped but with rounded corners, had no heatshield and had like a ribbed look to it --_--_--_-- <=== best I can draw using keyboard lol oh and wasn't no where near as fat as the cat I could just about see further up

I have to choose a tip and im totally stuck for choice, here is the link I was given to pick 1 from and let him know what I choose. http://www.tailpipes.co.uk/retail/retail_tailpipes_1.php

Chris

PS as for exhaust piping I just asked for 54mm and he just said 2 inch,I was thinking just to use the same as the CS system, be easier

 

[Andres3165]

Im sorry but never thought to get a picture of it lol, i'm kind of hoping maybe a few people can post pictures of theirs, I can tell you for certain what it looked like though, it was kind of rectangle shaped but with rounded corners, had no heatshield and had like a ribbed look to it --_--_--_-- <=== best I can draw using keyboard lol oh and wasn't no where near as fat as the cat I could just about see further up

I have to choose a tip and im totally stuck for choice, here is the link I was given to pick 1 from and let him know what I choose. http://www.tailpipes.co.uk/retail/retail_tailpipes_1.php


Chris

PS as for exhaust piping I just asked for 54mm and he just said 2 inch,I was thinking just to use the same as the CS system, be easier

Mine:

Andres