here i´ve tried a sample based method to generate engine Sound:

Concept: motorengine-sound with sampling

I´ve used only one sample from standing to max rpm... within a loop/loop-centerpoint is dynymicly controled via incoming engine speed... --> start patch and move the red fader
I think it works very if the patch gets a windowfunction or to generate fades while moving the centerpoint...
I´ve atached the patch including sample.

Do you have a tip?