Scott Posted October 8, 2011 Share Posted October 8, 2011 Just thinking out loud really. With all the options on modern ECUs I was wondering if it would be possible to have an emissions friendly map for when the cars need to go in for their MOTs. What actually causes high emissions levels? Would it be possible to have a "lean map" toggle that could be switched to for when the car goes in for an MOT? Quote Link to comment Share on other sites More sharing options...
Benjy Posted October 8, 2011 Share Posted October 8, 2011 Unburnt fuel causes high hydrocarbons, which produces excessive carbon monoxide. If you can get the air/fuel ratio as close to 14.7:1 as possible, it'll burn efficiently and be cleaner. My NA went through with no cats, 0.18% CO and 10ppm HC, possibly because i replaced the fuel pressure reg about 3k miles ago, I dunno. When it was last at SRR, Charlie commented on how good the air/fuel ratio was throughout the range. I imagine a switchable map is do-able. Girly and Mental. :-D Sent from my iPhone Quote Link to comment Share on other sites More sharing options...
Tricky-Ricky Posted October 8, 2011 Share Posted October 8, 2011 I used to have to tweak my EMU map on my old S14 to get it through MOTs so quite doable. Quote Link to comment Share on other sites More sharing options...
Scott Posted October 8, 2011 Author Share Posted October 8, 2011 Unburnt fuel causes high hydrocarbons, which produces excessive carbon monoxide. If you can get the air/fuel ratio as close to 14.7:1 as possible, it'll burn efficiently and be cleaner. My NA went through with no cats, 0.18% CO and 10ppm HC, possibly because i replaced the fuel pressure reg about 3k miles ago, I dunno. When it was last at SRR, Charlie commented on how good the air/fuel ratio was throughout the range. I imagine a switchable map is do-able. Girly and Mental. :-D Sent from my iPhone That's easy to do on an N/A though, getting it to work that way on a single turbo where the tubby is starting to spool is going to be difficult. Quote Link to comment Share on other sites More sharing options...
Scott Posted October 8, 2011 Author Share Posted October 8, 2011 I used to have to tweak my EMU map on my old S14 to get it through MOTs so quite doable. Sounds good to me. I'll see what Ryan can do for me By the way, my main reason for thinking of this was because I got a road side emissions check the other day. To be able to pull up to one and flick a switch would be like a get out of jail card I would imagine. Obviously very handy for MOTs as well though Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted October 8, 2011 Share Posted October 8, 2011 Aftermarket cams can be the killer. Obviously you will need an effective cat in place. But good mapping and a switch-able exhaust, with tame cams *could* get around this, depending how keen and savvy they are. The age and status of the car may, or may not, help. Quote Link to comment Share on other sites More sharing options...
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