The Porsche 718 Cayman GT4 is quite clearly a lot more serious about aerodynamics than the cheaper GTS. At a mere glance, you can help but notice GT4-specific features like the more prominent front splitter and a massive fixed rear wing.
There are, however, some more subtle touches. Take that vent just in front of the front lid – as noted by Jason Fenske AKA Engineering Explained, it’s to eject hot air from the radiator without mucking up the under-body airflow. On the GTS, where aero isn’t as high on the agenda, heat is merely chucked out of some holes under the car.
The GT4 seals this area, but what’s particularly interesting is the nature of the panel used for the job – it’s dimpled like a golf ball.
Golf balls, as Fenske tells us, are dimpled for a reason. This creates a more turbulent boundary layer over the surface, creating a later separation point than you get with a more laminar airflow. This means a smaller wake, lowering drag and allowing the ball to travel significantly further and with more accuracy.
This principle works with cars, so you might wonder why we’re only just seeing a production car adopt dimples. It turns out, though, that this has been done before, and we’re not just talking about the time Mythbusters coated the whole exterior of a car in dimples.
Various VW products have used under-body dimples in the past, and yes, one of those was rather fittingly the Golf. Bugatti went one step further with its ‘Bolide‘ track-only special, by adding a roof scoop with dimples that can be extended and retracted to control the airflow as necessary.