I managed a 2:07.5xx and I was shifting as close to 8k as I could hear it. Perhaps even shifting a bit earlier than 8k will get a bit more torques out of it and quicker acceleration. Something else I've noticed with some cars equipped with a turbo is, the boost falls off the farther into the RPM range you go so short shifting a turbo may even be a general rule to go by. The AEM doesn't suffer a huge falloff but it does reduce boost some as you run up the engine. I'm sure some of the real motor heads can explain or refute this better than I.