Discussion in 'E46 M3 (2001-2006)' started by robmarrs, Nov 8, 2018.
Are both 100 & 200 cell going to pass the MOT?
Are they both going to exhibit more noise than std?
I'm sure standard E46 Cats are already 200 cell
400 I believe.
Yeah I thought standard were 400 and CSL are 200
I could well be wrong apologies if so, but i'm sure I was told they are 200 cell
In that case I have no idea haha
Me and you both lol!
There is a report on the design of the E46 M3 Exhaust System here:
Clearly states in Section 4.2.1 200cell cats for the standard M3. I personally don't believe there is any evidence other than pure conjecture that the CSL had different cats to the standard M3... it seems crazy that it would given it had more aggressive cams and exhaust valves which would have harmed emissions, to have reduced the cats as well seems nonsense.
I think the mix up between 400 and 200 is peoples understanding of how to quote it... They are 200Cell.psi so its a statement of cells per area... I believe some people double that number as there are 2x cats... but this is wrong... So vendors state (liek VAC for instance: https://store.vacmotorsports.com/su...metallic-cat-use-w-stepped-headers-p2096.aspx)that OE was 400cell and Supersprint is 200cell but I can definitively say that OE is 200cell and then I guess that Supersprint are actually 100cell... which I believe I have read somewhere but I cannot confirm.
I thought I was right
Well thats my knowledge well and truely corrected, interesting article, thanks for sharing the knowledge. 100 cell it is then.
I've got 100cell Miltec cats on mine and it passes it's MOT no problem.
100 cell twin cats should pass mot emissions easy. As long as map is good,healthy engine and the cats get properly hot you’ll get a pass no problem.
The csl uses thinner material for the whole exhaust (exhaust manifolds are the same on the regular M3 after 2004ish) so the internals are the same but weigh less. OEM cats are 200 cell
I’ve got a set of milltek/hjs motorsports 100 cell cats for sale if interested
I'm glad to hear that you can pass MOT with 100cell cats. Can I ask if anyone has passed with 100cell cats with a CF airbox and cams? (280/272 or 288/280)? I need to pass an emission test and I have just gone to CF airbox, 280/272, full supersprint sports exhaust with 100cell cats... so I am hoping I can pass... the engine is rebuilt and running rich at the moment but after i break it in I hope to get it tuned to something better.
US M3s have 400 cell cats as standard.
Euro M3s all have 200 cell cats as standard.
Unless you've changed your injectors then no tuner should be touching the part throttle / idle tables so the ECU should hold a steady 14.7:1 at idle / fast idle providing the following:
- The fuel trim limits havent been exceeded.
- There are no exhaust leaks pre-cat.
- There cats are high quality and are up to temp
- Your O2/Lambda sensors arent knackered.