The CFD Development of Ken Block’s Hoonipigasus Porsche

Behind the front tire is a section with 4 vortex generators/turning vanes/strakes angling outboard. This helps take the dirty air in the fender well and re-energize it under the car. This increases good flow to the floor and the tunnel. Two of the vortex generators also have titanium grind tabs on them as they are the lowest point on the floor to help when the car hits the ground (#1). A vortex can be seen forming from the vortex generator.

Rear Wing Aerodynamics:

The rear wing is our Verus Engineering V2x which has been used by many including BBi at Pikes Peak. It is a proven dual-element wing that can make massive amounts of downforce.

The V2x is based on our V1x which is a 300mm chord wing. To make it the V2x, we add on a 200mm chord 2nd element that was specifically designed to work with the main element. This is only the 2nd bottom mount V2x as it is usually swan mounted. The decision to go bottom mount was driven by two key things; wing location on the x-axis based on aero balance and mounting location. The wing was mounted to the rear of the gearbox and with its location for aero balance, the bottom mount was the best solution.

We do lose a little efficiency being bottom mount, but that is made up by the custom endplates for the application. The endplates were optimized based on the shape of the car and how the airflow was moving around the car. A large amount of optimization was done on these in yawed flow seen in cornering. Besides the unique shape, they incorporated 3d printed vents that were bonded onto the carbon. Using 3d printing allowed more complex shaping to get the outcome we desired.

A unique issue when working on aero balance and wing placement was the fact that we needed to keep the factory gutters on the car that run between the roof and the door and run halfway down the C-pillar. This caused a unique horseshoe vortex off the back that was abnormal for most vehicles we have seen. This vortex is low energy and destroys flow to the rear wing. Because of this, the rear wing had to be higher than normal.

9 comments

  1. Thanks for sharing this Mike, and thank you to Paul/Verus for detailing elements of the aero development.

    I hope all involved in the project have a great time at Pikes Peak!

  2. This is such an awesome article, written in a way to make something very complex fairly easy to understand for someone with a limited understanding of aerodynamics such as myself.

  3. Are there any rules against moveable aero? Seems like this would be a perfect application of sliding side skirts and possibly even fan driven suction for low speed downforce.

      1. So sad that this didn’t get to make a run due to the engine failure. Hopefully they do some real shakedowns before next year’s race.

  4. How effective are the NACA ducts at cooling the engine/gearbox? Does it affect the pressure flow under the car thru the diffuser?

  5. Pretty effective, but more testing is still needed. No real change to the diffuser based on before and after CFD runs.

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