R33 GTR Emissions

[Tomisw]

Hello!

Writting from Spain regarding passing emissions here. Bear with me in this wonderfull and amazing trip that is doing miracles to be able to drive your car one more year.

To put you into my perspective my "goals" are: 0.2% CO fast idle (3k rpm) and 0.3% CO idle. Also lambda can´t go past +-0,03. I so happens, I won´t pass inspection.

Last week got 1.11 and 1.04 respectively and 1.053 lambda. While my AFR gauge was showing 13.9-14.5 AFR.

Was able to track down the lambda discrepancy because an exhaust leak, but don´t know good and effective ways to knock down those CO emissions since can´t realy move AFR much and here in Spain e85 is quite limited.

Currently running the following mod list:

z32mafs, apexi pfc, arc intercooler, n1 r33 turbos, 700cc sard injectors, and sard cat. Stock bottom end and head. PFC shows voltage variation on lambdas and mafs so I would say all are ok.

Car had been on a lift for 6 months without running and went straight into inspection.

I heard that retarding ignition can help with this sort of issues, but don´t know by how much.

Any other tip, or thing, or product I can use to get lower CO values while keeping AFR untouched?

Thank you all in advance!

Edited April 9, 2019 by Tomisw

[GTSBoy]

You should be able to get rid of all the CO by removing fuel.  Don't trust your AFR gauge.  Put a proper 4 gas analyser on the car (you'll need to find a workshop with one).  Running stoich or very close to it should produce very little CO.  Might make a shit tonne of NOx, but you didn't ask about that.

I say "should", but you have 700cc Sard injectors.  These are, to put it politely, shit.  You may well find yourself needing to replace them with something modern to try to get a better spray pattern at low pulse widths.

[Tomisw]

Well. Good news. Sealed the exhaust the best I could, gave it some revs for some time and luckily "passed" emissions. Idle CO 0.05% and 1.025 lambda, fast idle gave me 0.5 or something like that but... that could be because the sard cat not being enough (?).

Also I´m suspecting that my map might be not existant but I don´t know. I´ll be sending it for mapping in a couple of months or so I belive since here in Spain finding a competent tuner is quite hard.