Dedicated Exhaust Discussion

[Striker01]

Where might I be able to buy the $300 Polish headers that someone referred to in another thread?

Here are the ones I ordered. $315 shipped to OK.

https://fmic.eu/174005-exhaust-manifold-header-bmw-n52-e90-e92-328i-2006-2011-fmic-exh-bb17.html

I'm hoping they will fit with the Z4 arms, if they ever arrive.









Front set is very close to the engine block, not sure it it will be ok or not.



Rear is not even close with the stock 328i engine arms. I've tried every way I could think of to get them on, I'm either not smart enough or they just don't fit.

[FredK]

Where might I be able to buy the $300 Polish headers that someone referred to in another thread?

[82eye]

wow that looks good

[hoveringuy]

Perfect solution other than the complexity of fabrication. Has performance and retains AC. Would be nice if there were a simpler solution that did the same.

No A/C, #1 is in the way.

[JRowe]

Perfect solution other than the complexity of fabrication. Has performance and retains AC. Would be nice if there were a simpler solution that did the same.

[e30davie]

That is a very nice job. Lots of effort gone into that.

[hoveringuy]

Advantages. They were CHEAP, I think I paid under $100 for them (still needed the flanges...). They're AWESOME, nothing like hydroformed factory tubing. They look baller.

Disadvantages. Alignment on the flanges that go into the ports is critical, if they get slightly skewed the headers are hard to fit. Interfere with the A/C compressor, routing is completely wrong to keep the A/C. "some assembly required"

To construct them I got short sections of the proper diameter tubing for the head, then expanded one side in a press so the header tubes would slip in (kinda like a swedge?) I didn't have the Z4 mounts when I fabricated these, I had to clearance the mount a hair but if I had fabricated them with the mount it wouldn't have been an issue. #2 runner also comes to within 10mm of the engine bay wall.

Other notes. I'm not a huge fan of V-band clamps particularly at the header. The flanges here are perfectly parallel so the exhaust mid section slides in cleanly. Makes exhaust work super-duper easy!

[hoveringuy]

I used S54 headers because all the BMW DOHC motors have the same cylinder spacing (outside the M30...) so I suspected they would work.

[JRowe]

I've seen a few solutions in other threads about exhaust manifold solutions. I thought it would be nice to put them all into one place.

To my knowledge, I've seen three options

- Modify S54 exhaust manifold
- Use factory N52 manifold
- Modify aftermarket N52 header

It would be great if people can post what they've done here (maybe even link to the post). This seems to be the most difficult fabrication needed for this swap. Would be great to come up with a simpler solution.