After watching Dave Birdsall's video on Outrun across multiple formats, including the ZX Spectrum, I and others remembered how bad it was due to the very low framerate. I decided to try and make it playable.
I have to say I prefer it normal speed, but it was fun to try it overclocked.
I used FUSE emulator in Windows and cranked it up to 300% speed and it was actually playable. I didn't really do it justice with my driving skills, but netherless here it is running at a decent speed albeit with the equivalent of a very overclocked spectrum.