Is it possible to regrind a VX cam for more efficiency? I figure there should be some room for improvement... especially with efficient driving habits. My VX never sees more than 2500rpm (and that's high!)
You really shouldn't have much of an issue with the fact the VX already has two separate cam profiles. The fact you rarely see over 2500 rpm means you rarely engage the "power" profile anyway, as 2500 rpm is the switchover point.
Basically, your cam profile is already optimized for 2500 and lower RPM.