Why VarioCam off at 5120

[REBible]

Thanks for the quick reply. I figured someone had done the testing. But I couldn't find it referenced anywhere.

I realize that you make your living by selling upgraded engines, and it costs you money to obtain information like this. I appreciate your sharing it.

Why the big drop off at such low rpms? I have read what I can find on the web and there does not appear to be any consensus.

Is it the cam grind.. e.g. is the valve lift and duration too small? Or is it muzzled on the intake and or exhaust?

thanks
robert