This was from a new 03 Z06 with about 800 miles on it. It was stock except for SV0 30 injectors and a Blackwing airfilter, the increased airflow and and larger injectors picked up the power but the custom tune was needed to assure best overall driving conditions and max performance.

These are the results of before I did the tuning of PCM calibration and then after custom tuning of the PCM.

After Tuning ------------------------------------------------------ ---------- Stock Tune


One more tweak needs to be made to tune PE but otherwise the increased PE timing has allowed engine to perk up nicely.
Engine idles well, hot or cold.
Tires now break loose real easy in 3rd gear.

I then did a 2nd 03 Z06 with the same mods and got the same performance gain results.