Qustion about Exhaust systems

[dafababa]

I know that this has been asked befor but I did a serach and did not find what I was looking for. I have an Mazdaspeed Pro.
Question 1. Should I get a cat back system. mabey 3" or so.
and 2 if I do should I leave the stock muffeler on or use the one that comes with the system?

Question 3 Will this even help the car? ie. noticable HP gains?

 

[ZiO]

You will notice HP gains, but i have read and heard not to go with the 3"... you will have too much pressure loss..... and go with the new muffler as well. Thats where are the hidden power mainly is... there is not too much of a hp difference b/w a strait muffler change or a cat-back system... the catbacks give slightly more, plus if you ever happen to fall under the car you can see nice stainless steel pipe.

 

[chdesign]

I've said it once I'll say it again the best exhaust system for a turbo setup is one that produces 0 backpressure. with NA you want some amount of back pressure but FI the best thing for it is to have no backpressure

 

[sundevilMP5]

chdesign took the words right out of my keyboard...if you have a factory turboed car then usually one of the easiest things that you can do for performance gains is switch out the exhaust system...

i'm not to sure about how much hp you will gain over the racingbeat system though, since it is technically an aftermarket system already...

but just as an example...i know some guys with the wrx that gained 15-17hp at the wheels just by switching out the exhaust system

good luck

 

[I-Am-Chris]

Thank You 3" all the way!!!!

 

[dafababa]

Thank you guys very much for the advice. Should I keep the mazdaspeed muffler that came with the car? Also what system is the best performence/value

 

[chdesign]

As of now there are no turbo exhausts for the protege or the MSP. It seems the best 2 or most used turbo mufflers out there are the Apex'i N1 and the HKS mufflers. I am partial to Apex'i and Blitz myself. The Blitz Nurspec universal muffler is avaiable with a 3" inlet for turbo apps. As for the piping you are going to have to get it all custom bent or buy alot of mandrel bends and weld it up. Hope that helps. 3" would be great but 2.5" will work just fine also. A new exhaust on the MSP isn't going to help too much till you can get the O2 housing and downpipe replaced also they are pretty small from looking at pictures of them. Get your O2 housing ported and a 2.5-3" downpipe made and you should see some nice gains out of just that.

 

[dafababa]

o2 housing ported sounds $$$ and warrenty voiding? Also can i just go to auto zone or pepboys to get the down pipe?

 

[I-Am-Chris]

The Blitz is Super Nice but It comes at a cost. Its Loud as Hell!!

 

[dafababa]

so from all of the advise i have got it sounds to me like i should start with the downpipes and then get a 3 inch stainless steel straight pipe get rid of the 2 cats and put one high flow on. is this sound like the best setup for my turbo msp?

 

[twilightprotege]

hey

my thoughts from my mate's nissan 200sx (here in australia - japan it's the silvia) research. 3" is close to right on the money for turbo'd apps, but overkill for na apps. 2.5" would be heaps for na, 2.25 would prob be best because you do need a little bit of back pressure. not much, but a little. if you plan on working the engine etc to allow 12000rpm, then yes, 3" for na. but if not, 2.25" is heaps and you'll save money

later

 

[Equinox]

yeah on N/A application, my bet is on 2.25 as well