Here is the one I put on my midpipe.  2.5" oval style.

I don't think you'll need the 02 sensor bung, unless your header only has one on it.  My nismo has 2 so I don't need it.



P.S. The shop showed me old and new magnaflow boxes.  Old style say hi-flow, new style is exactly the same, but with a sticker over the 'hi'.  Weird, but whatever.  I'm lovin' it like a bad McDonalds commercial.

naturalsk8ter17 wrote:

Is there really a difference between a hi flow cat and a resonator? performance wise I mean

A resonator is there to keep the noise down while the catalyitc converter is there to remove polutants from the exhaust flow. So to answer your question yes there is a difference.

Here is an article that you may find interesting...
Resonator

Catalytic Converter

The Pitt wrote:

like ive said before, high flow cats are retarded IMO.  its either gonna not flow very well like your stock cat or it will fail the sniffer test.  if you are worried about it just leave your stock one.

Fixed.  I have gone from stock midpipe to straight pipe with hi flow cat and love it.  The straight through setup lost a bit of power in the low end, and breathed better up top, but it was not worth the trade.  With the cat in there, she feels better off the line and does not choke or anything up top.  I have not done a sniffer test so I cannot attest to that.  I still have a stock midsection with 15K on the cat, so I have the best of both worlds when it comes time to pass smog.  IMHO of course.

/$.02

Last edited by Marcatarkon (2008-08-26 15:26:48)

naturalsk8ter17 wrote:

Marcatarkon wrote:

The Pitt wrote:

like ive said before, high flow cats are retarded IMO.  its either gonna not flow very well like your stock cat or it will fail the sniffer test.  if you are worried about it just leave your stock one.

Fixed.  I have gone from stock midpipe to straight pipe with hi flow cat and love it.  The straight through setup lost a bit of power in the low end, and breathed better up top, but it was not worth the trade.  With the cat in there, she feels better off the line and does not choke or anything up top.  I have not done a sniffer test so I cannot attest to that.  I still have a stock midsection with 15K on the cat, so I have the best of both worlds when it comes time to pass smog.  IMHO of course.

/$.02

so you had a strait pipe and werent satisfied so you threw a hi flow cat in there to give you some low end?

Pretty much.  The straight pipe was
a) way to loud for my taste
b) felt like I lost a little off the line oomph
c) was a poor design and always ended up giving me an exhaust leak where the Header met the midpipe.

So I put the stock midpipe back on there.  I regained the bit of low end and it quieted it down 'some'. 

My fix was to add the magnaflow AND a stock midpipe header side flange that I picked up used.



Now, it may not be 'true' 2.5" all the way through due to the stock flange, but it is the best I could come up with.

1) Good low end
2) Quiet sound
3) no choking up in the higher RPMs that I notice.

Last edited by Marcatarkon (2008-08-26 17:13:46)

So what shape is the one the stock 07 has? I want to get the same one just to make sure there are no issues.

Or does it not matter the shape, as long as the piping is the right diameter?

oh, and just to be 100% sure, the stock piping is 2.25, right?

Last edited by whysoSERious (2008-08-26 20:08:56)

The shape shouldn't matter.  I never paid attention to it when I looked under my car.  I'll have to look under it the next time I go outside.

Well the round 2.25 is like $66 and the long oval 2.25 is 83. If the shape doesnt matter, i'd rather just get the cheaper one.

http://cgi.ebay.com/ebaymotors/MagnaFlo … 0281715748

This is the one i was looking at specifically.

anyone to comment for the b16 before i make purchase?

I ordered it today, I will let everyone know how the install goes once it is done.

whysoSERious wrote:

so the cat came in today. I was curious though, is there a way to tell if it is really a high flow cat just by looking at it, or are all the magnaflow ones high flow?
The website I ordered it from says it was high flow, but the box doesnt say anything. I am going to call the muffler shop tomorrow to have it put on, so I'll post updates when it gets done.

Same damn thing.  The shop I went to had old boxes and new boxes.  The new boxes were EXACTLY the same, but with a bit of tape over the 'HI' portion.  Maybe the newest packaging have them removed all together.  I asked the shop owner why and he just shrugged his shoulders.  My best guess would be either marketing, liability, or some idiot suing them...

wtf are you serious?  what's their reasoning?  don't tell them it's a high flow cat, if they're already this stupid they shouldn't ask.  if they do ask, just say it's supposed to be lighter and there's been issues of the stock cat clogging and catching fire underneath.  i know that's not true but they may not lol.

wow cali sux