Well I did some logging today and saw a commanded afr of 16:1 and well my WB said that it was right around there, so how lean will it start hurting it? This was at cruising speed and I just put on LT headers not sure what they will do to a tune but will they do this?

 

At cruise, it's not a problem. You'll start to notice the power drop off above 16.5-17:1, but as long as the load is light, you're not going to do any damage.

 

i got mine set at 15.6 now..used to have my 5.3 set to 16.5

 

I guess better fuel mileage as well right? Also how close will the actual AFR follow the commanded?

 

Here is the log for you EFI live guys

 

If it's tuned properly then the actual should be very close to the commanded. I have HPT so I can't look at the log. I had mine setup to run about 16:1 for a while with no problems. I'm running in now at around 15.5 at light throttle/cruise speeds.

 

Sure you can. Anybody can download EFILive and view logs for free: http://www.efilive.com/download.aspx

 

ahh yes very true... guess I'm too tired to think of that.... I even had it installed on here at one time...

 

Your commanded AFR is puzzling. Mind sending me your tune file? justin at blackbearperformance.com.