I've tuned 2 Corvette C6 today.
A C6 LS3 2009 and a 2010 Grand Sport.
both 100% stock, Octane 93.
stock 2009 & 2010 stock tune are about the same.
But the GS has 6-7 KR from factory between 4000 and 6500 rpm
with factory tune at wot, the 2009 is 23 degree timing and the GS : 15 degree (KR).
The two owner has previously dynoed the cars (same day, same dyno), the GS is 25rwhp less.
When I substract 3-4 degree timing, KR are still there.
Thoughts ?