Z4 MC Manifold or 100 cell cats upgrade & remap

[flatout]

I'm considering upgrading the M's air flow system and have narrowed it down to these two options, just wanted to get people's views on these two options.

Looks like the cats will be the more expensive option but the manifold seems hard to come by, at least in RHD anyway.

I also read somewhere that the M shares the same manifold as the e46 m3 - is this true? If so, i guess an e46 supersprint fitment would suffice..

What do you think?
Rich

 

[Wondermike]

It seems like an expensive upgrade for any potential performance gain, I'd be looking at the RPI exhaust that Beedub got http://www.z4-forum.com/forum/viewtopic.php?f=9&t=13601

The Supersprint price list from CA Automotive might help with part numbers for the manifold and cats.

http://www.ca-at.co.uk/products-Y2FyX21ha2U9Ym13JmNhcl90eXBlPXo0bSZjYXRfaWQ9MiZjb21wX2lkPTMz.html

 

[Top pup]

I would think that the cats are more of a restriction than the manifold so thats where my money would go.
Didn't BMW use 200 cell cats on the CSL? If they did then there must be a decent gain there.

 

[flatout]

I would think that the cats are more of a restriction than the manifold so thats where my money would go.
Didn't BMW use 200 cell cats on the CSL? If they did then there must be a decent gain there.

So does that mean the stock m3 and z4m use a 400 cell cat then?

 

[Top pup]

So does that mean the stock m3 and z4m use a 400 cell cat then?

I've read they were 400 cell on quite a few websites, but just to be sure I did a bit of searching and turned up an article on the M3 by the OEM exhaust manufacture stating that the cats are 200 cell.
That being the case I'm not so sure now about the cats, TBH reading that article I don't think there's going to be lot to gain on the exhaust system regardless of what you do.

 

[flatout]

.....but just to be sure I did a bit of searching and turned up an article on the M3 by the OEM exhaust manufacture stating that the cats are 200 cell.
That being the case I'm not so sure now about the cats, TBH reading that article I don't think there's going to be lot to gain on the exhaust system regardless of what you do.

bugger, was doing maths based on 400 cells/100 cells = 4 times more gain, hence a decent HP gain. Thorney's w/site refers to 400 cells for the OEM, also a friend who used to work for bmw said the csl had 200 and m3 400 cells.

Might go ahead and do it - my exhaust was made by H&S who also do 100 cell cats so will get them to do this as well.

 

[Top pup]

bugger, was doing maths based on 400 cells/100 cells = 4 times more gain, hence a decent HP gain. Thorney's w/site refers to 400 cells for the OEM, also a friend who used to work for bmw said the csl had 200 and m3 400 cells.

That was my thinking too, but the article by Arvin Meritor states 200 cell for the M3, and I can't see why the Z4M would be different, here's a link to the article it's well worth a read.

http://www.unofficialbmw.com/images/e46m3exhaust.pdf

Might go ahead and do it - my exhaust was made by H&S who also do 100 cell cats so will get them to do this as well.

Fair enough, I think you will still get a gain, let us know how you get on.

 

[flatout]

Thanks for all the feedback above.

Following on from the above, can anyone suggest a reputable company to do my ecu remap - i know there are lots of tuning companies around, but just wanted to know which ones people on here have used.