# Front wing in ground effect (open-wheel)

> How does an open-wheel front wing work close to the ground?

- 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/front-wing-ground-effect/ · JSON: https://xemstudio.com/api/geometry?object=front-wing-ground-effect · Plain text: https://xemstudio.com/objects/front-wing-ground-effect/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

- Running a wing close to the ground accelerates the flow under it, so downforce rises as ride height falls, until the flow separates and force drops sharply (Zhang & Zerihan).
- Southampton's double-element wing reached CL 3.03 at h/c 0.079; below that, downforce fell sharply. A cited single-element study saw a force reduction of up to 25%.
- UIUC front-wing tests found flap angle, flap planform and endplate size all moved CL markedly (Jasinski & Selig).
- Used on: Formula One and Champ Car front wings (UIUC test geometries).
- The file is a reference example built by Xem Studio from the numbers above (Zhang & Zerihan test wing; mount at h = 0.079c (30 mm) for peak downforce.). Sizes the sources do not fix are illustrative; scale the example to your own vehicle.

## Sizes

| parameter | value or range | source |
|---|---|---|
| Max CL (double element, high flap) | 3.028 at h/c 0.079 | Zhang & Zerihan |
| Max CL (double element, low flap) | 2.588 at h/c 0.066 | Zhang & Zerihan |
| Single-element force reduction | up to 25% | Zhang & Zerihan (cited study) |
| Model reference chord / span | 380 mm / 1100 mm | Zhang & Zerihan |
| UIUC semi-span model | 46.23 cm span, 33.02 cm reference chord | Jasinski & Selig (UIUC) |

## Where the files are

- University of Southampton / AIAA Journal: [Aerodynamics of a Double-Element Wing in Ground Effect (Zhang & Zerihan, AIAA J. 41(6), 2003)](https://eprints.soton.ac.uk/22605/1/AIAA-2057-653.pdf) — 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/front-wing-ground-effect/index.json · license: https://xemstudio.com/files/hardware/front-wing-ground-effect/LICENSE.md

- front-wing-ground-effect-rear-wing: [STEP](https://xemstudio.com/files/hardware/front-wing-ground-effect/front-wing-ground-effect-rear-wing.step) · [STL](https://xemstudio.com/files/hardware/front-wing-ground-effect/front-wing-ground-effect-rear-wing.stl) — dual element rear wing: span 1100 × chord 380 mm at 1°, endplates 200 mm, inverted NACA 4412 section (mounts from below)

## Questions

**What ride height gives most downforce?**

For the Southampton double-element wing, h/c 0.079 (about 30 mm on a 380 mm chord); below that downforce fell sharply.

## 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/)
- [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/)