Before I get hounded about the seach botton, I've spent the last few weeks searching this topic to death and would like some fresh opinions on it

Well I believe I've got my street tuning pretty much there with the Hondata S300 and PLX R-500 WB sensor.

I've got my fuel maps looking nice and pretty and the A/F numbers are all within +/- 0.1 of their targets.

This weekend I tried doing some HP measurements using the R-500 which has so far proven to be quite consistent. The point of this exercise was to see what A/F ratio the engine seemed to work best at. After doing many tests it seems clear to me that the engine likes running at 13.5/1. Running the engine with more fuel consistently dropped the HP readings I was getting (~5HP less with 13.1/1).

So my question is this: should I be concerned about running the engine this lean?

I've checked the plugs and they look good and clean (a little on the white side, but no metal bits). The knock sensor on the R-500 suggests that all is ok.

I will be heading to the dyno soon to do my final adjustments but this question of safe A/F ratios will be relevant before I go...

Thanks,
Doug

 

i'd like to know this too

 

Sorry to bump this... know one has anything to add?

 

13.5 is not that lean for an NA car (edit: on good gas). As long as you're not knocking and your EGTs are ok you should be fine. Leaner is meaner

 

13.5:1 is what my car was tuned to when I last had it on the dyno with a wideband. My previous motor had the same tuning. No issues as long as you use good quality gas. I miss the Ultra 94 gas in Toronto. All we get here at most is 93...

 

that is a perfectly safe afr to shoot for on an NA motor, so keep on truckin,

 

how it is with AFR and Lambda, someone know the conversion-factor ??

 

13.5:1 is a bit on the leaner side of things but if you have the fuel and ignition maps good so it won't knock then more power to ya nemesis0104's R liked it around 13:1 on MI 93 but then again it was a very consvitive tune... I really think that it's different for each motor

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Mr. Svonda &raquo;</TD></TR><TR><TD CLASS="quote">how it is with AFR and Lambda, someone know the conversion-factor ??</TD></TR></TABLE>correct me if i'm wrong but 14.7:1 AFR is 1.00 Lambda

 

Knowing your ign maps will help to decide the final A/F.