Dual-element (two-element) rear wing — dimension sheet
Source: Xem Studio, https://xemstudio.com/objects/rear-wing-dual-element/  (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
- A dual-element wing adds a flap behind the main plane, separated by a small slot. The slot lets fresh air energise the flap's suction side so the pair can run far more camber before stalling than one element could.
- In Southampton's ground-effect tests the optimum slot was a 3.2% chord gap with 2.4% chord overlap, and the wing reached CL 3.03 (Zhang & Zerihan). In UIUC open-wheel front-wing tests, raising flap angle from 14 to 24 deg lifted CL from 1.95 to 2.37 (Jasinski & Selig).
- HP Academy pairs dual-element rear wings with 500-600 hp cars and larger splitters, i.e. more downforce means more drag and needs front balance to match.
- Used on: Champ Car and F1 front-wing configurations tested at UIUC.
- The file is a reference example built by Xem Studio from the numbers above (Geometry of the Zhang & Zerihan test wing; aoa is its 1 deg reference incidence.). Sizes the sources do not fix are illustrative; scale the example to your own vehicle.

parameter  value or range  source
Main element chord  223.4 mm (~0.59c)  Zhang & Zerihan
Flap chord  165.7 mm (~0.44c)  Zhang & Zerihan
Reference (combined) chord / span  380 mm / 1100 mm, AR 2.89  Zhang & Zerihan
Optimum gap  0.032c (12 mm)  Zhang & Zerihan
Optimum overlap  0.024c (9 mm)  Zhang & Zerihan
Max CL, high flap angle  3.028 at h/c 0.079  Zhang & Zerihan
Flap deflection range tested  4-44 deg (3D), 6-41 deg (2D)  Jasinski & Selig (UIUC)
CL at alpha 6 deg  1.95 (flap 14 deg), 2.37 (flap 24 deg)  Jasinski & Selig (UIUC)
Swan-neck LMP wing, flap +8 deg  1413 lb downforce  Mulsanne's Corner

Files elsewhere (not hosted by Xem Studio; license as stated by the publisher):
- University of Southampton / AIAA Journal: Aerodynamics of a Double-Element Wing in Ground Effect (Zhang & Zerihan, AIAA J. 41(6), 2003) — web — Publisher's page; dimensions are facts — https://eprints.soton.ac.uk/22605/1/AIAA-2057-653.pdf
- University of Illinois / SAE: Experimental Study of Open-Wheel Race-Car Front Wings (Jasinski & Selig, SAE 1998) — web — Publisher's page; dimensions are facts — https://m-selig.web.engr.illinois.edu/pubs/JasinskiSelig-1998-MSEC-SAE-Trans-V107-S6.pdf
- High Performance Academy: Aerodynamic performance devices for club level cars: front splitters — web — Publisher's page; dimensions are facts — https://www.hpacademy.com/courses/aerodynamics-fundamentals/aerodynamic-performance-devices-for-club-level-cars-front-splitters
- Mulsanne's Corner: The Rise of the Swan Neck (2009 LMP rear wing CFD study) — web — Publisher's page; dimensions are facts — https://www.mulsannescorner.com/rearwingLMPCFD2009.html

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