Bite Size Tech: Lotus E22 Asymmetric Rear End (Support Pylon & Exhaust)

Lotus had already let the rest of the world in on their asymmetric secret when they showed off the render (pre-launch) of the E22's asymmetric nose but none of us realised just how far it went...


The rear of the E22 is just as interesting as the front of the car, with the team utilising a Rear Wing support pylon that joins under the central section of the Mainplane but has a kink midway down and terminates on the left hand side of the Crash Structure. This is a 75mm offset and seems strange on it's own, but to marry this, the exhaust pipe also bends around 45 degrees as it exits the engine cover with it's outer edge residing roughly 75mm from the centreline too.

It's been argued for some time by myself and other tech analysts, that due to the fact that the Turbo has the MGU-H attached to it, the amount of exhaust energy available for 'exhaust blowing' will be minimised in 2014 onwards. Could Lotus therefore be the first team visibly trying to invoke a performance advantage by skewing the exhaust?

Lotus clearly have a specific intention in bending the exhaust where they have and most likely wish to make gains aerodynamically that others will struggle to replicate. Lotus must have completed their CFD runs modelling the whole car, to take in account the inconsistencies that asymmetry can produce and is further echoed by the teams use of other asymmetric parts. The regulations going forward put a much heavier restriction on the use of both CFD and Wind Tunnel testing to offset the return of in-season testing. This will undoubtedly hinder any teams wanting to assess the kinked exhaust concept as the computing power to process the whole car vs half of it is more than double whilst as we know replicating ballistic energy like the exhaust is altogether another black art.

If I were a gambling man I'd propose that the bend in the exhaust is placed in order to increase the boundary layer (against the bend), invoking more turbulence within the airflow it will likely increase the upwash created by the exhaust and therefore increase the aerodynamic link between the Diffuser and Rear Wing. It may also aid in smoothing the transition when the driver is off throttle.  It certainly is an interesting design and won't have been done to simply be different, there is something larger at play....