# Swan-neck rear wing mount

> Why do race cars hang the rear wing from swan-neck mounts?

- 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/swan-neck-wing-mount/ · JSON: https://xemstudio.com/api/geometry?object=swan-neck-wing-mount · Plain text: https://xemstudio.com/objects/swan-neck-wing-mount/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 swan-neck mount holds the wing from its top (pressure) surface, leaving the underside clean. The underside of a car wing is the suction side that makes most of the downforce, and bottom mounts disturb that flow and cause early separation (HPA).
- In a 2009 LMP CFD study the same wing went from 1019 lb downforce on conventional mounts to 1299 lb on swan necks at similar drag, because the mount-induced separation disappeared (Mulsanne's Corner).
- HPA says conventional mounts are justified only by structural limits, rules or looks.
- Used on: Audi R15, Acura ARX-02a.
- The file is a reference example built by Xem Studio from the numbers above (2009 LMP wing box (Mulsanne's Corner); mount geometry illustrative.). Sizes the sources do not fix are illustrative; scale the example to your own vehicle.

## Sizes

| parameter | value or range | source |
|---|---|---|
| Conventional mount, bespoke 2009 wing | 1019 lb downforce, 214 lb drag | Mulsanne's Corner |
| Swan neck, same AoA | 1299 lb downforce, 186 lb drag | Mulsanne's Corner |
| Swan neck, flap +8 deg | 1413 lb downforce, drag within 4% of 2008 car | Mulsanne's Corner |
| Reverse swan neck (over trailing edge) | 1288 lb downforce, 186 lb drag | Mulsanne's Corner |
| Downforce recovered by swan neck | ~280 lb at the same settings | Mulsanne's Corner |

## Where the files are

- 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
- 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

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

Index: https://xemstudio.com/files/hardware/swan-neck-wing-mount/index.json · license: https://xemstudio.com/files/hardware/swan-neck-wing-mount/LICENSE.md

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

## Questions

**Is a swan neck stronger?**

Not inherently; HPA notes conventional mounts are chosen for structural strength or rules, while swan necks are chosen for aerodynamics.

## Fits with

- [Single-element rear wing (race car)](https://xemstudio.com/objects/rear-wing-single-element/)
- [Dual-element (two-element) rear wing](https://xemstudio.com/objects/rear-wing-dual-element/)
- [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/)