A few days ago I put up a video of the conversion of this Irvine XR15 from RC car format to Sow Goodyear racer format: • Irvine XR15 Part One -...
Now it's time to test run it and to measure performance. The aim is to get it turning an APC 7x4 at around 20,000rpm in flight, which means exceeding 18,000rpm on the ground. Test flights will confirm whether this is enough to drag a Slow Goodyear model around at the speed limit of 26 seconds for 10 laps - equivalent to about 138km/h.
The tests showed that the engine looks likely to be able to do the required speed and has excellent re-starting habits. There was quite a big performance drop in the last run where I swapped the Taylor glow plug for a used Novarossi #1 plug - about 500 rpm. There also seems to be some inconsistency in the APC data between the 6.5" and 7" props which makes tracking the power output a bit difficult. It does seem like these Irvine car engines are significantly held back by their timing, although that probably suits our needs for Slow GY.
Here's an old video of Slow Goodyear Team Racing to illustrate the task: studio.youtube...
12 сен 2024
