5 Gas Emissions Results

[STAATS]

Not an overly interesting topic and obviously the usefulness of this data is heavily dependent on the regulations and testing regimes of your particular regulatory authority so I merely provide this as an as-is data point.

As part of my modification approval for my E46 M3 build I had to undergo emissions testing.

Regulatory Information:
Regulator: Department of Transport - Western Australia (will refer to as DoT)
Applicable Standards: ADR - NCOP - VSB 14
Emissions Requirements: Euro 3

To test to Euro 3 correctly you need to undergo an IM240 test, but there is minimal to non-existent options for this locally so DoT provide applicable thresholds for 5gas analysis - I have attached these. As you can see the highlighted fields show their main focus area is Total Hydrocarbons (THC) and NOx.

Vehicle Information (those with potential impact on emissions):
- Evolve Carbon Fibre Intake
- TTFS MAP (GM 1bar) Sensor
- Schrick 280/272 Cams
- SuperSprint V2 Stepped Headers
- SuperSprint HJS Metallic Cats (Sect 1)
- SuperSprint Resonated X-pipe (Sect 2)
- SuperSprint Sports Muffler
- Paul Clause Tuning
- SAP deleted
- Standard Euro O2 sensor arrangement

I have attached the initial 5gas test which is done at 3000rpm and then IDLE. The car is warmed up extensively beforehand and then the test is done at 3000rpm first (until the measurements settle) then the car is dropped back to IDLE and the measurements taken again (once settled). You will see using the SuperSprint HJS 100cel cats I am unable to meet the THC requirement at IDLE or the NOx requirement at 3000rpm.

To be able to pass, as we do not have regular testing requirements, I swapped the Stock Cats back on but made no other changes. I have attached the passing test results I received with the Stock Cats installed.

As a result, although I will swap back to my SuperSprint cats before I get racing, I will hold on to my Stock Cats in the off chance I ever get a defect notice (Yellow Sticker) and have to pass inspection again... although that is reasonably rare over here. So in retropsect it is very lucky I didn't go all out and get SuperSprint V1 Stepped Headers... as then I wouldn't be able to swap back and forth so easily...

This won;t mean much to most of you as the US testing seems to be focused on emissions readiness triggers over OBD-II rather than actual emissions test... but hopefully the testing results help give a frame of reference to anyone who is in a place that requires emissions testing with regards to the back-to-back difference between used Stock Cats and SuperSprint HJS Metallic Cats.

For reference the Stock Cats had ~100k miles on them and the SuperSprint HJS Metallic Cats had ~5k miles at the time of testing. Also as my car is a Euro build when I refer to Stock Cats i am referring to the 200cel Sect 1 Euro cats not the US Cats in header pipes arrangement.

Hope this helps someone as it was near impossible to find any reference data like this when I was trying to plan my build ensuring I'd be able to pass 5 gas emission testing



WBM346Z - SS Sect 1 Metallic Cats - DoT Inspection - Fail - 250718.pdf .

WBM346Z - Stock Cats - DoT Inspection - Pass - 250731.pdf

[bmwfnatic]

The Netherlands here.

Pretty similar tests, here we call it the 4 gas test. It’s the same but without the NOx.

Our tolerances are also bigger, up to 0.3% CO at idle. And all other tests are evaluated at 3000 rpm. The HJS SS pass fine here.

[STAATS]

Yer I think with a bit of effort I could tune out HC at idle by trying to run as lean as possible... Dropping NOx at 3000rpm without impacting power would be slot harder. So I can definately see how passing a 4gas is possible with HJS cats reasonably easily... I have MSS Map switcher so if I had sufficient funds to tune for emissions, I believe it could be possible to pass 5gas with a specific map but yer would be expensive in tuning time.