Just thought I'd let you all know, just because your O2s read .890s doesn't mean your A/F ratio is ideal. My friend's 02s were reading .885 to .905 on the street. He went on the dyno using wideband O2s and his air fuel was no lower than 13.5 : 1 <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> and was above 14 : 1 <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> in many parts of the rpm range!!!

The weird thing is that richening the A/F to 12.8 : 1 only added about 3 rwhp?!? We did gain nearly 20 rwtq in the lower rpms though.

Derrick

 

Been there, done that. All the MAFT write-ups said to get your O2's to the .89-.9 average. I had to lean the hell out of mine to get it there, but when I wide-banded a week later, it was waaay lean. The guy moved my WOT dial back to +0 and I gained 30rwhp immediately. The internet is a dangerous place <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

I've seen more recent theory which indicates not to worry about it so long as it between .85 and .95. Mine reads about .93 at a 13:1 AFR.

 

<img border="0" alt="[Banging Head]" title="" src="graemlins/gr_banghead.gif" />
<img border="0" alt="[Banging Head]" title="" src="graemlins/gr_banghead.gif" />
<img border="0" alt="[Banging Head]" title="" src="graemlins/gr_banghead.gif" />
<img border="0" alt="[Banging Head]" title="" src="graemlins/gr_banghead.gif" />
(Amount of years been trying to tell people NOT to use their STOCK O2's)

Time to go have a <img border="0" alt="[chug]" title="" src="graemlins/gr_chug.gif" />