We'll for my entry, I flew between Crown and Garden in normal space.
Trip was about 6:30 @ between 430-464m/s
If Engineers can double my speed, a race between the 2 would in theory take 3:15
At 6:30, it would be a bit boring (but maybe not if it was a group race?)
Also, I made this map for my video, maybe of interest here,
I was thinking you would use SC. Would be a bit dependent on the transition times but would be good fun anyway. Always looks cool with lots of ship close together in SC.
Just sending my entry in now.