Air Fuel Ratio?

[JP112_89]

I put the LM-1 on the TTA earlier this week. Tuned from 55mph to... 18#'s boost. My a/r fuel ratio displayed in the 10:XX. I took decreased the fuel at WOT 10 increments (-12.5%). Also, I increased the timing 21/19* from 20/18.

I tuned from 55mph again and the a/f ratio came in at 12:9 Showing .5 knock at the same boost level.

Is 12:9 to lean? I am using 93 octane mainly, with a couple gallons 100 octane for a safety net.

 

[WS6]

Is 12:9 to lean?.

At WOT? I think so.

But I'd like to now what others think is too lean.

 

[Chuck Leeper]

12.9 is close to a decent N/A ratio...11.2-11.5 would be where I'd want to start.