I've been wondering about what's going on in the 5k rpm range, too. If you look at the plots from the first few kits on scienceofspeed.com and daliracing.com, you'll notice that rather than just being sloppy, they actually have big dips in the torque curve. I'm actually wondering if it's the butterfly valves in the intake manifold. Might be interesting to do a couple runs with them locked closed, and a couple runs with them locked open.
-Mike
-Mike