Originally Posted by MD SRT6

If the monitoring device ie.. wideband or tailpipe probe are behind the cats(all 4 ) it throws the reading off by .50 roughly because the cats burn up some unburnt fuel. 11.0 would really be 11.5 on the rich side and 13.0 would be 12.5 on the lean side. Gotta keep this in mind. And if you lift the pedal at all then reengage the engine will dump fuel and you will be temp. lean but then it will richen back up as soon as it sees you reengage. These are some complicated *** cars. But once you understand how they work it's all manageable. Temporary leanness on these cars is ok as long is it's not more than 1-3 sec's, I ran 13.1-1 for over 15 minutes on the dyno and not even a nip at the electrodes. Hope this helps some! This is all considering no meth and no nitrous because with either of these you need a much richer environment like 11.0-1. By the way in your case I would gap the plugs at .030 -.035. The wider the gap the leaner the engine, the closer the gap the richer the engine to the point of misfire. The only reason my gap is so close is the nitrous was blowing out my spark. You should not have to go this close.

Originally Posted by 240M3SRT

Thanks for the info and advice. My o2 sensors are before the cats, one in each header. I regaped the plugs today to .035(im getting fast at swapping spark plugs).

The temp was 68 degrees out and A/F was 11.8-12.5 most the time, everynow and then it would tap 13.0 for a millisecond. What do you think of that? Can we conclude here that most you guys thing 12.5 is safe?

Now i will say one other thing. Everysingle time like clock work at 5700rpm in the top of 4th gear it goes straight up to 15, 16, 17......its running out of fuel. I think bigger injectors would help here. Id like one of you fellow 185mm guys to try it in a safe place your cars have to be doing the same thing.

Heres my first attempt at a video see if this works:
http://s17.photobucket.com/albums/b7...nt=afratio.flv