So, I also misunderstood your post @Owen.C93
I thought you were talking about this metal fence on the floor and not the tunel itself:
Because when you put more pieces toghther then E21 sidepods make more sense.
So, let's get back to observation of Matt Somerfield:
korzeniow wrote:SomersF1 Matt Somerfield
Lotus E21 - Exhaust & Coanda Ramp with Cross-Under Tunnel, Unlike RBR the bodywork doesn't smooth into the floor behind http://t.co/uSBidpsM
There are post-2009 rules stating that sidepod bodywork 50mm above the floor must meet tangential and minimum radius regulations. Hence the sharp edge of the tunnel'.
But why Lotus' ramp doesn't smooth into the floor like RBR's?
Maby there are also other rules forbiding from putting some extra aero pieces on the floor behind certain point.
Because when you look at the metal fence I highlighted on first picture, then you can conclude that by it's particular shape you are allowed to extend your ramp.
This can be best seen on picture made by @Blackout:
(right click and open in new tab)
You can see the diffrences between those two solutions and how the shape Lotus metal fence overlaps the ramp shape.
Maby this enahces the effectivnes of the tunnel?