By any chance, does the VVT/VANOS/WIGGITIZER on my '08 MCS start actually changing the intake valve timing at about 4500rpm or is it a continuous change right across the whole rpm band? I've been led to understand that variable valve timing only comes into effect at higher rpm's. Am I right on this? Trying to pin down a power drop-off that's starting at ~4500rpm. Thanks for any help.

 

I'm not certain that the current MCS has more than exhaust-side VANOS (infinitely variable valve duration), but either way, both Valvetronic (infinitely variable lift) and VANOS would presumably be adjusting lift and duration across the majority of the rpm range based many variables.

The cars that have brought about the "it only kicks in at high rpm" idea are cars with traditional VTEC setups, where the system is essentially just a second camshaft or set of lobes that the engine changes over to at a fairly specific rpm.

 

The MCS only has single VANOS...

which is variable valve timing on the INTAKE side. And from my understanding it is continuous across the entire rev range.

 

Ahh... intake side. I knew it was one or the other and that it was simply VANOS, not Valvetronic.