Just saying this out loud... I'm able to advance timing more with 93 without knock than 87, only because 93 burns slower am i able to get more hp while the timing is advanced.
87 = Xhp
87 with timing advance (knock and reduced hp) xhp
93 = xhp
93 with timing advance = XXhp > 87 @ Xhp
I'm no tuner but this was our experience while tuning my Rav4.
Makes perfect sense.
If I was 40 years younger I would be looking for the Toyota OEM Supercharger available for the v6.
Not sure if my stock v6 could take the abuse but......