Thanks for the explanation, yes you're right "nvemulate" is listed as option and can be set and queried. When I set it to 30, nvclock tells me it is 30 when I do nclick -q nvemulate.
However my engine still does not work and the renderer string did not change either:
OpenGL vendor string: NVIDIA Corporation
OpenGL renderer string: GeForce4 488 Go/AGP/SSE2
OpenGL version string: 1.5.6 NVIDIA 87.62