need advice RE: Air to fuel ratios

Dilemma-

The car goes for a tune on Friday at a place that specifically does LS/LT series tuning. It is about 1.5 hours away from me. My dilemma is that the cur runs and drives fine right now, but my a/f ratios are 14-15:1 at rest and partial throttle... They jump around a bit too upon let-off.

I don't want to do any damage to the motor, so should I just trailer to the tuning shop and let him handle it, or do you think I am okay babying it to him with those a/f values?


I do not have a handheld to do a quicktune, so no go there...

Drove her into work today Very happy overall. She drives pretty good considering it needs a tune. It just stumbles on let-off pretty good. Temp stayed between the 2nd and 3rd bar on the porsche gauge all the way in.


Goes in for an inspection tonight and finally I'll be a legal hybrider! I guess my only complaint is that it's noisy as hell inside, but hey- it's a track/street car. quiet and comfort were two things specifically excluded from the build. I didn't get on her much yet due to the tune, but I can already tell that it's going to be an impressive car to drive

Sounds good...we want video, 'duke!

There is nothing wrong with having the motor run in the 15s at idle and at cruise (low load events). The only thing I would worry about with it is heat and how well the LS styled motors handle it. I've been running in the 15s on a straight six in a BMW for years now without problems and with great success gas mileage wise. Have even seen my tuner do the same on 600+ rwhp motors with success. A proper tune with proper spark timing shouldn't have issues. After the tune, if you still see 15s, I recommend at least watching coolant and oil temperatures just to be on the safe side.

As for a simple safe AFR, cruise and idle (if it holds idle that is) should be somewhere in the 14s to the 15s, accel somewhere in the 12s to 13s, and WOT somewhere in the 12s to 10s (matters on application).