yeah i agree with ^^^, you got enough fuel to handle 18psi, with all those dyno runs you did you should've attempted it IMO especially it was the perfect time to do it. even if you think it's a timing advance issue, i don't think it would've been a problem. you wouldn't go lean at all. at least you would be 300+ at the wheels. i'm going to the dyno today and i'll see my numbers on 13-15psi. i will find out for sure if this timing advance is such a big thing that all of us are scared to attempt passed 15psi. i think it's all about the fuel mixture and not all about the timing. i've read many articles concerning this and talked to an engineer concerning our cars and the timing advancing with the SAFC. as long as you have enough fuel kicking out of the injectors and have the right fuel mixture, you're safe! dyno and wide band 02 is the key. many of us here are amature tuners, and for those who detonated did not know what they were doing. that's what 'cause them to spend thousands of dollars on a rebuild. so those attempting to go passed the limit make sure you know what your are doing.