View Single Post
      12-03-2012, 06:50 PM   #2
Dave W.

Drives: Porsche 951, 1992 Eagle Talon
Join Date: Apr 2012
Location: SF Bay Area

iTrader: (0)

Which emmission gases do they test for over there?
From my research the lowest emmissions are found at 14.7 AFR. If you go richer you will lower NOx (oxides of nitrogen) but raise hydrocarbons (HC) and CO. If you go leaner NOx goes up while HC and CO go down. You can lower NOx by retarding ignition timing, so the best bet is to tune it lean and retarded.

If you use E85 it will lower HC and CO but raise NOx.
I like to do a pre-test to see which emmissions are out of range on my car first, then make adjustments and re-test later.