This is not as extreme as it may get, but certainly I don't think I could get much more in the way of power for engine bay space. It's a tongue-in-cheek variation of my fastest track monster yet, which will shortly be tilting at the test track leaderboards.

- FlyingNightfury.png (821.41 KiB) Viewed 4620 times
With 1571.2kw (2107hp) and weighing just 1302.8kg (which I could easily chop down if I made it RWD and took out a couple of cogs), it has a kw:kg ratio of 1.21, or a hp:kg ratio of 1.62! I put in so much aero on this crazy ride that you can still drive it around the track without ending up flying backwards through the pearly gates on fire (to quote Clarkson), though it's nowhere near as quick on a track as my
real Time Attack car, which has a
hp:kg ratio of 1.21, due to the extra drag from ventilation.
As you can see from the screenshot it's good for a little over 370km/h on the long Daffy Flyer! Who knows what would happen if I tried to make it a landspeed record attempt vehicle...