Test-build of the preliminary tunnel underfloor design. The Traxxas battery boxes angle up from a central low point on the underside of the chassis, so they leave some room for underfloor tunnels that the flat floor wasn't utilizing. The outlet end of the floor, and the rear diffuser, run at about the wheel/axle centerline. Aggressive, but effective...

The bulky rear suspension hanging out in the tunnel isn't ideal, but the rear diffuser is run significantly higher than before so I suspect the underfloor flow will find it's way through.

One thing this floor messed with was the center-of-pressure. The original flat floor design didn't kick up until just forward of the rear wheels whereas these new tunnels actually start ahead of the centerpoint of the car's wheelbase. This is generatating more flow much farther forward. Perhaps too far forward...

On some test runs without the rear wing, it was obvious the Center of Pressure was ahead of the COG, generating some very oversteery drifting handling at speed. Slidey fun but very precarious. Bolting on the big rear wing pulled the system into a very nice balance.