Ok folks, I need some advice. I finally added my 93 octane tune that I got from Brenspeed. I filled up with gas (93 octane), then immediately added the tune. Then I couldn't wait to try it out. From a dead stop there seems to be some loud pinging in the engine, much like my 89 GT does when I run anything lower than 93 octane. Could this possibly be because there was still some 87 octane gas in the tank? I ran it down to about a 1/4 of a tank. Do I need to run a couple of tanks full of the 93 octane, before I continue to stomp on the gas again? Any advise?