The secondary shaft needs to be driven by something powerful enough to drive the load in reverse.

The primary input's gear is fixed, so the secondary is doing all the work.
Also, in this configuration the main input is not running, therefore the secondary input would have to be using stored energy, or be another engine.

Still very interesting, looking forward to seeing the dyno results.

We must close the water gun gap!

"they'll never really give anything they enjoy up, no matter how repugnant its production might be."

Fry: Ewww Slurm comes out of your behind?!?
Glug glug glug