PCM Diagnostics & Tuning - What's a good AFR to shoot for on an LS2




redtan
09-01-2009, 02:57 PM
Been doing some tuning myself with hptuners and an innovative lc1 wideband and have gotten to the point of finetuning the AFR and timing tables.

I've set my timing to a pretty conservative 24-26* and tuned the VE to almost perfection. Right now I have the AFR at 12.8 across the board except for 4000 or so RPM where I bump it up to around 12.65 or so for more safety at peak torque.

I don't have access to a dyno to try multiple tunes to see which setting yields better power, and I knew that when I chose to spend my money on self tuning rather than going to a pro dyno tune. So that's why I'm hear to get some input on what you guys have seen as the best place to be AFR wise.


pdsq98gt
09-01-2009, 04:19 PM
From what I've seen, 12.5 works best on the LS2.

racecar
09-02-2009, 12:14 AM
The generic standard is 12.7 will make max power, and 14.7 is best for economy. My engine with a 233/239 cam runs about 14.3 cruising, and I aim for 12.7 at WOT.
If you run 12.8 all of the time, idle and mid range, that's prety rich, it can foul spark plugs.


redtan
09-02-2009, 07:25 AM
If you run 12.8 all of the time, idle and mid range, that's prety rich, it can foul spark plugs.


Well clearly I run stoich (14.699) at idle and part throttle...I'm just wondering about WOT fueling.

The 'accross the board' comment was meant for the PE table.

Patrick G
09-02-2009, 08:56 AM
Are you verifying the WOT A/F ratio with a wideband O2 sensor or are you just trusting that the PE multiplier will give you the proper A/F ratio? Having said that, I have found that the LS2s are happy being a little fat. Around 12.5:1 keeps the knock sensors happy, especially around peak torque.

Phil99vette
09-02-2009, 09:10 AM
I usually tune for 12.3-12.8 at the peak torque number on the dyno and 12.8-13.2 at peak horsepower. I usually make 5-6 pulls and put the best numbers together in the final tuneup.

redtan
09-02-2009, 09:28 AM
Are you verifying the WOT A/F ratio with a wideband O2 senso

Yes, in my OP I mentioned I have an innovate lc-1 wideband.

Thanks for the answers.