Side skirts (ground-effect sealing) — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/side-skirts/  (sheet CC BY 4.0; files Xem Studio Design License, https://xemstudio.com/license/)
Basis: Design rules and figures from the cited sources; example geometry by Xem Studio
Catalog version: 2026-10-20

Sizes: see table below
- Side skirts seal the gap between the car's sides and the road so that low pressure built under the floor is not destroyed by air leaking in from the sides (Wikipedia, Ground effect (cars)).
- Lotus sealed inverted-aerofoil sidepods to the ground with flexible skirts on the Lotus 78 (1977) and 79 (1978); the advantage was so large that sliding skirts and then ground-effect floors were banned, with flat bottoms mandatory from 1983.
- Used on: Lotus 78, Lotus 79, Chaparral 2J.
- The file is a reference example built by Xem Studio from the numbers above (Dimensions illustrative; no skirt-gap figure in source.). Sizes the sources do not fix are illustrative; scale the example to your own vehicle.

parameter  value or range  source
Lotus 78 season  1977, five wins  Wikipedia
Lotus 79  1978, six wins and the drivers' title  Wikipedia
Chaparral 2J (fans + skirts)  end of 1970; led to movable-aero ban  Wikipedia
Flat-bottom rule  mandatory from 1983  Wikipedia
Ground effect returns to F1  2022  Wikipedia

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- Wikipedia: Ground effect (cars) — web — Publisher's page; dimensions are facts — https://en.wikipedia.org/wiki/Ground_effect_(cars)

Free files (Xem Studio Design License, Xem Studio; STEP + STL, 1 parts): https://xemstudio.com/files/hardware/side-skirts/index.json
API: https://xemstudio.com/api/geometry?object=side-skirts