Originally Posted by magneticred
Torque and horsepower do not peak at the same RPM. Horse power is related to torque X RPM. The point about shifting so as to maximize HORSEPOWER delivered is correct. An unmodified NA has a peak HP of
215@5700 and peak torque of
229@3000. Given that peak HP occurs just before redline, you will go fastest if you shift at 6000 RPM (or very close to it).
Both methods will give you the same answer, try it and see - either from actual dyno data in each gear or a single dyno pull data with the other gears calcukated mathematically.