So i just bought an 03 vette yesterday. I have tuning experience with my LT1 and L67 (SC 3.8) Are there any good writeups on tuing LS1's? I'm wondering what areas of the timing table need work and what WOT A/F ratio should be.

Any quick tips will help.

 

Congrats on your purchase!

The biggest difference in tuning LS1 vs. LT1 is how the spark advance tables are laid out. On LT1, it is RPM vs. MAP. On LS1 it is RPM vs predicted dynamic cylinder airflow. Also, LS1 has a "high octane" and "low octane" timing table which the PCM uses to estimate the optimum spark advance based on the history of knock retard.

In my experience, Gen III motors (LS1) generally want to be a bit richer at WOT then their LT1 counterparts to help stave off spark knock. LS1s come tuned fairly aggressively from the factory (e.g. I see spark knock retard on stock tunes fairly regularly, and actually measure power gains by removing timing to correct the knock retard), the biggest gains coming from commanding a reasonable WOT AFR.

 

So I leaned out the A/F ratio starting at 13.0:1 and richening to 12.8:1. I haven't touched the timing table but I do have random kr I'm going to try to get rid of. I had it with the rich mixture and it hasn't gotten any worse leaning out out. I noticed a huge gain with the air intake and leaning out the mixture.