Welcome to the site. I am not disputing you but I fing it hard to believe that the GXP will run 13.6 out of the showroom. This, I would have to see in person.
fastest GXP's in the country all of them are stock....... sorry last time I submitted a slip is from aug at norwalk when I went 14.01 in 95 degree weather
But I have a date to get the Torque management removed from the PCM and some tuning done..... I'm feeling some 13.1 13.2's this spring
oh and don't hate the LSx is a wonderful engine :smt045