<<at 4000 rpmīs the engine gives a real kick. I do not know what causes this real surge in power. Is it the ignition, the cpu or the air intake that allows for so much extra power.>>
It is a combo of the variable valve/cam timing, the ecu controlled ignition, SFI fuel management, and a big breathing feature-the
variable tuning of the intake manifold . There is a damper in there that actually changes the lenght of the intake for the higher RPMs. Top that with the 24 valves and you have a pretty powerful engine for a 6.
Don't know on the Euro's, but US is spect. at 217.
They are also known for having a flat torque curve, but suffer dead stop accelleration cuz of a 2:65 rear ratio [ which I like for cruisin.] That is helped a little with the 1st gear start.Considered a nice improvement of the earlier 124s.