# Single-element rear wing (race car)

> What is a single-element rear wing and how does it make downforce?

- Category: Car design › Car aero
- Kind: Standard part
- Basis: Design rules and figures from the cited sources; example geometry by Xem Studio
- Page: https://xemstudio.com/objects/rear-wing-single-element/ · JSON: https://xemstudio.com/api/geometry?object=rear-wing-single-element · Plain text: https://xemstudio.com/objects/rear-wing-single-element/sheet.txt
- License: dimension sheet CC BY 4.0 (Xem Studio); files Xem Studio Design License (free to use and sell from, not to redistribute as files: https://xemstudio.com/license/)
- Use in every chat: add https://xemstudio.com/mcp as a connector (https://xemstudio.com/use-with-ai/)

**Exact dimensions.** True size, with no printing tolerance added.

## Notes

- A race-car rear wing is an inverted wing: its profile and angle push the rear of the car down, trading drag for rear grip. HP Academy notes that more curvature gives more downforce and more drag, while flatter profiles are more efficient but make less downforce (HPA rear wing theory).
- Downforce rises roughly linearly with angle at low angles while the lift-to-drag ratio slowly worsens; peak downforce comes with a little trailing-edge separation, and large-scale separation makes downforce fall (HPA).
- Size matters strongly: in a 2009 LMP CFD study, shrinking the wing from 2000 x 300 mm to 1600 x 250 mm cut downforce by 34% and drag by 31% (Mulsanne's Corner).
- Used on: Audi R15 (2009 LMP), Acura ARX-02a (2009 LMP).
- The file is a reference example built by Xem Studio from the numbers above (Span/chord from the 2009 LMP wing box (Mulsanne's Corner); 6 deg is the UIUC test incidence; endplate height illustrative. Scale to your car.). Sizes the sources do not fix are illustrative; scale the example to your own vehicle.

## Sizes

| parameter | value or range | source |
|---|---|---|
| Downforce vs angle | Roughly linear at low angle; L/D slowly worsens with angle | HPA rear wing |
| Peak downforce condition | Slight trailing-edge separation; large-scale separation reduces downforce | HPA rear wing |
| LMP rear wing box, 2008 rules | 2000 mm span x 300 mm chord | Mulsanne's Corner |
| LMP rear wing box, 2009 rules | 1600 mm span x 250 mm chord | Mulsanne's Corner |
| 2008 benchmark wing (CFD) | 1739 lb downforce, 226 lb drag, L/D 7.69 | Mulsanne's Corner |
| 2008 profile scaled to 2009 box | 1146 lb (-34%), 156 lb drag (-31%), L/D 7.36 | Mulsanne's Corner |
| Wind-tunnel test incidence (open-wheel front wing) | alpha = 6 deg at Re 1.1e6 | Jasinski & Selig (UIUC) |

## Where the files are

- High Performance Academy: [Aerodynamic performance devices for club level cars: rear wing theory](https://www.hpacademy.com/courses/aerodynamics-fundamentals/aerodynamic-performance-devices-for-club-level-cars-rear-wing-theory) — web — Publisher's page; dimensions are facts
- Mulsanne's Corner: [The Rise of the Swan Neck (2009 LMP rear wing CFD study)](https://www.mulsannescorner.com/rearwingLMPCFD2009.html) — web — Publisher's page; dimensions are facts
- University of Illinois / SAE: [Experimental Study of Open-Wheel Race-Car Front Wings (Jasinski & Selig, SAE 1998)](https://m-selig.web.engr.illinois.edu/pubs/JasinskiSelig-1998-MSEC-SAE-Trans-V107-S6.pdf) — web — Publisher's page; dimensions are facts

## Free STEP/STL (1 parts, Xem Studio Design License, Xem Studio)

Index: https://xemstudio.com/files/hardware/rear-wing-single-element/index.json · license: https://xemstudio.com/files/hardware/rear-wing-single-element/LICENSE.md

- rear-wing-single-element-rear-wing: [STEP](https://xemstudio.com/files/hardware/rear-wing-single-element/rear-wing-single-element-rear-wing.step) · [STL](https://xemstudio.com/files/hardware/rear-wing-single-element/rear-wing-single-element-rear-wing.stl) — single rear wing: span 1600 × chord 250 mm at 6°, endplates 300 mm, inverted NACA 4412 section (mounts from below)

## Questions

**Is more wing angle always more downforce?**

No. Downforce rises roughly linearly at low angles, but once large-scale separation occurs downforce falls while drag keeps rising (HPA).

**Does a bigger wing always help?**

It adds downforce and drag together; the 2008-to-2009 LMP wing-size cut lost 34% downforce and 31% drag (Mulsanne's Corner).

## Fits with

- [Dual-element (two-element) rear wing](https://xemstudio.com/objects/rear-wing-dual-element/)
- [Swan-neck rear wing mount](https://xemstudio.com/objects/swan-neck-wing-mount/)
- [Gurney flap / wickerbill](https://xemstudio.com/objects/gurney-flap-wickerbill/)
- [Wing endplates / side dams](https://xemstudio.com/objects/wing-endplates/)
- [Front splitter](https://xemstudio.com/objects/front-splitter/)
- [Splitter tunnels (front diffuser)](https://xemstudio.com/objects/splitter-tunnels-front-diffuser/)