ZHP exhaust on a 323iT, cat-back?

So I am going to pick up a ZHP exhaust, just the muffler section. I have a few options:

1) Just weld muffler on after 2nd resonator (I'd need a Y pipe cause I have a single 2.5 inch mid pipe). This would be the easiest, cost the least, but be the least effective

2) After 1st resonator, build 2 1.5 inch mid pipes made of stainless back to the ZHP exhaust (which on stock ZHP requires 2x 1.5 inch pipes)

3) Custom stainless exhaust from cats back (most expensive, most effective)

I am looking for a deeper sound, without anything too loud or aftermarket. It would be nice if I could pick up some hp along the way.
Thoughts?

Some questions:
1) ZHP exhausts are stainless correct?
2) Do I have to go with stainless for my mid pipes? (I know it would be best?)
3) I've heard rumors that if I dont do cat-back I could lose some low-end torque?

Anyone???

Or should I get a 330 exhaust for cat-back then just weld the ZHP muffler on?

option 2 sounds the best to begin with.

Where are you getting your numbers from? 1.5" piping on a ZHP? I thought it was 2" ID piping, and I thought the midpipe on the 323/328 was 3"? The ZHP muffler also isn't a higher performing muffler, it may sound a little bit different, but it seems like you're going through a lot of work for a nominal at best change in tone.

From what Ive read,

323/328 is twin 2.25 inch pipes til 1st resonator, then single 2.5 inch pipe the rest of the way

325/330/ZHP is twin 1.5 inch pipes from cats all the way back. Everything I've read says this is soo much better than single 2.5 inch pipe, and is a much better design

You are right that Im not going to be getting amazing gains or a huge change in tone/ volume, but I just want a little bit (can't be too loud b/c of where I live). I am also looking for a cost-effective solution, and don't want to spend much over $300 for parts AND labor.

Ideas or thoughts? Thanks

http://www.realoem.com/bmw/showparts...35&hg=18&fg=20

This mentions 50mm, which, when converted to inches, is 1.96", or 2" for convenience in the States for thr 325/330/ZHP...

http://www.realoem.com/bmw/showparts...26&hg=18&fg=20

This mentions 65mm, which, when converted to inches, is 2.5, so you're right there about the 323/328.


Do you have emissions testing in Ohio? If not, consider headers. They will give a great tone(IMO), give nice performance gains, and you won't have to hack anything up or weld anything.

Oh, thanks for the correction on the 325/330/ ZHP piping...that would have been a bad mistake!!

We used to have emissions in OH, but now we don't...and probably won't get them back anytime soon. I've been looking into ebay headers...but I really dont want anything TOO loud- just very sporty and deep, and if I could pick up some Hp or Torque along the way, That'd be great.

So if I did ebay headers, kept my stock cats, deleted both resonators, and did twin 2' pipes all the way back to the exhaust, do you think that'd be effective and sound good?

I've got some vids of my 330 with headers and completely stock exhaust. Yours wouldn't be too different, and I think it'll achieve what you want.

Ahh crap youtube is down for maintenance. Stay tuned, I'll post them soon.

There you go

Nice! Sounds about what I want. And you still have both resonators right? If I went ahead with headers and a full 330 exhaust with a ZHP muffler, I'd probably lose at least 1 resonator, so it'd be even louder.

Thanks for all of your help man. Now I've just gotta figure out what kind of 2x 2.0 piping Im gonna do from my cats back...is stainless needed, or should I do an X pipe?

Originally Posted by TiAgTouring

Nice! Sounds about what I want. And you still have both resonators right? If I went ahead with headers and a full 330 exhaust with a ZHP muffler, I'd probably lose at least 1 resonator, so it'd be even louder.

Thanks for all of your help man. Now I've just gotta figure out what kind of 2x 2.0 piping Im gonna do from my cats back...is stainless needed, or should I do an X pipe?

Yeah, in that vid I had all resonators, muffler, etc, everything was stock besides headers. Now I don't have headers anymore(but I will again soon), but I removed the middle resonator, and really like how it sounds with the stock exhaust, though it does drone a little bit now. I don't think an X pipe is necissary on an inline engine... on a V engine I can understand it, but I know that some people have done it on here, and it really hasn't done much of anything for them.

Sounds good. Now all I have to do is find a full 330 exhaust and ZHP muffler. I am definitely doing ebay headers and race cats. Thanks for the info Adam- tons of help!

Been searching for awhile, and I know I need a 2.25 inch Cat...but do I just need one?

Over on bimmerforums, there is a forum just devoted to engine transplants in various BMW's.