You can create a load on the engine while sitting still. I do it all the time at the track and it is referred to as preloading. If you pull the eBrake and let the clutch out just to where it is grabbing, but not pulling you forward (revving to keep the car running) then you can rev the engine as much as you want to see if it will spool. The small amount of resistance being caused by the clutch will cause a load. Be aware that you can burn your clutch out doing this and that most that preload have a good clutch in the car (ACT XTR6 here).