For anyone that says leaner AFR's are ok....especially leaner AFR's and LESS timing....I would love to see EGT data on that. Even going from 11 to 11.5 can increase EGT's ~300-400*.....now you start taking away timing its going to increase ~50* with every degree.
I've had an EGT gauge in my wrx since 2003 and in my STi since 2006 and have never found any leaner tuning strategy be EGT friendly. Or even make enough extra power to be worth the diminishing safety net.
And as far as the places that post up 11.5-12 AFR plots in PPB.....i ask everytime i see one what the EGTs were on the car and the answer everytime has been "the car didnt have a gage".
From my pov tuning to 10.8 and having a nice EGT safety window available if the car develops a leak and leans out to 11.8 a much better strategy than tuning the car to 12:1 and having it lean out to 13:1 during a leak and melting holes in the pistons.
And as someone already mentioned.....heres a JDM Version8 fueling map....8.88 Targets.....how do the people that always bring up washing cylinder walls and getting fuel in the oil explain how stock subaru motors survive the stock fueling mapping?