Exhaust piping

I found this on ebay today...should i get it and put w/e muffler i want on it? will i get the same power from it if i was to get a magnaflow or somthing like that?
ebay.com type these numbers in the search bar
Item number: 230222442042

2.5" is a little too big for a 2.0 I4.

[edit]  haha.  they are claiming 8-15 hp gains!
a plus for this system is that it gives the option of deleting the cat or not.[edit]

i think that custom exhaust systems sounds much better than premade kits and they give you the same performance.  they also save you a bunch of money.  ive got a custom 2.25" set-up on my 2.3liter with deleted resonator, bullet muffler, and a 4" tip.

how big should i get then instead of 2.5 i will talk to the guy and see if he has anything smaller. And if i was to get this shoudl i delete the cat or buy another cat...and if i have to buy another cat then my total will come out to roughly 300 ...so if that is the case then why not just buy magnaflow catback for 350 with shipping.

2.25" or 60mm is usually recommended.
 
 

so if i was to use 2.5 i would loose power? the guy replied back and said that is the only piping he has and bla bla bla 

2.5 takes a lot of your low end torque an HP away.

The engine needs exhaust velocity and a certain amount of back pressure for low end torque.  If the pipe is too big you will gain the capacity (volume) to produce hi-end hp, but will also reduce the velocity affecting the available torque at low end. Too little and as Ken said, you will lose some/too much road worthiness.  
It can be a fine line, and is almost always a compromise, but unless you're gonna turbo the car, and or turn into a track-only car, stick w/a smaller diameter pipe.
And too, watch what you buy on eBay.  Too many cheap parts from fly-by-nighters that have no pre-production research or after-sale support.  You can get ripped off very easily.  I know I have from time-to-time.

well i emailed the guy and he said he can make piping with 2.25...now the question is should i get this or no and how would i go about installing this...does this need to be welded on...is the cost going to be more than 350?....i can get a magnaflow exhaust  sys for around 300-350. 

you will most likely need to weld.  2.25" would be optimal for piping for the 2.0 liter i think.  i cannot comment on the quality of the piping youre looking at on ebay however.  if you go to your local muffler shop or the like, they should have a large selection of quality piping to choose from that they will mandrel bend on the spot for you.  plus, youll get a warranty on the system.

custom > magnaflow.

but what will be the cost like i said if its above 350 then why bother with it and just put magnaflow which i can do my self. 

Only one way to find out, Dude!  Go (to several of them if you have that option) and ask them for an estimate.
 
 
 

dam...i got to set a day aside for this then...i noticed our OEM piping doesn't have any crush bends...does that mean i can use the stock piping and just take the muffler out and get the same hp gain or no, when i was under my car from the back i didn't see any crush bends it looked like straight piping except that the muffler ...or i think it was the muffler, it was real close to the engine.

Front to back: Manifold/header/pre-cat, cat (2 bolts/nuts,) resonator, muffler, tailpipe.

Sure!  I don't see why you couldn't use the stock piping and either remove or replace components....?

Oh, and the resonator doesn't really hurt anything, but might help with harmonic tones and back fires, so I would consider keeping it in the system.  On the other hand, a high-flow cat can be a nice addition!!

so if i want to keep my stock piping what do i need to remove and what should i keep?

can anyone confirm the size of the oem exhaust?  is it 1.75"?

quote:

ORIGINAL: 2.0Mazda08

so if i want to keep my stock piping what do i need to remove and what should i keep?

 
if i were you, i'd remove the resonator, and get a flow-thru style muffler. i cant see it being that loud since your using the stock piping.
 
but get prices first, and see how much a custom made catback would cost.
 

Look here. http://www.trubendz.com/home.asp?producttype=exhaust&productfor=mazda3_tubing&pagetype=productIndex

I found a few places that are doing it for 400 then i found one guy who seems to be flexible and is going to do a  full cat back with 2.25 with hi flow cat and w/e muffler i want for 300-350. should i do it...i think so...

it sounds promising.  good luck.

is it hard to install exhaust systems yourself if you have all the necessary components??? for example if i buy a Magnaflow or Vibrant catback?

if you buy a pre made exhaust like the brands you mentioned its a bolt on and you don't need a welder depending on the system, so yes if you are a bit mechincally inclined you can do it....just don't do it after you have driven the car. do it in the morning. 

well i installed my intake and my eibach prokit so i guess the next challenge is exhaust and header!

i just installed my CAI as well i will be doing exhaust next but can you post a pic of your intake set up by any chance i am trying to get an idea if i did anything wrong on my intake installation. 

i installed a SRIinstead of CAI therefore taking away the whole bumper removal hassle, but i do have pics-



both before my heat shield i installed to keep some extra heat away!!

and my car stock still on the lot: hehe


my car now - cellphone picture - muaha
sry for the largeness.

nicely done. easy install...mine was a bich. but why do you have a red fliter over there what is that for...bypass?