DOWNFORCE DIVISION CFD DATA
THE NUMBERS BEHIND THE WING.
We took the BCL GT wing formula and developed the DF profile through CFD around what matters: making serious downforce efficiently, controlling drag, and keeping the size, stance and attitude you expect from a BCL wing.
AND IT MAKES DOWNFORCE.
At 100 mph / 161 km/h, and a 12° wing angle, CFD predicted:
DF1800 — 267 lb / 121 kg of downforce
DF2000 — 344 lb / 156 kg of downforce
Results shown with large endplate configuration - Vengeance.
WHY THE CURVES CLIMB.
Downforce and drag increase with the square of speed. Double the speed and the aerodynamic forces increase roughly four times, assuming wing angle and airflow remain the same.
The speed curves are calculated from the CFD results at 100 mph / 161 km/h using that relationship—they are not separate CFD simulations at each speed.
CFD ANALYZED AS A COMPLETE WING.
The DF1800 and DF2000 were analyzed in CFD as complete wing assemblies—not just the wing profile on its own. Development covered both wing spans, three wing angles, four endplate configurations, revised support geometry and a 40° yaw case.
TEST CONDITIONS
- Airspeed: 100 mph / 161 km/h
- Wing angles: 2°, 7° and 12°
- Wing spans: 1800 mm and 2000 mm
- Endplates: Four configurations — two large and two small
- Yaw testing: 40° at a 12° wing angle
- Simulation method: RANS turbulence modelling
- CFD scope: Complete wing assembly, not full-vehicle CFD
Results below use large endplate - Vengeance configuration unless stated otherwise.
STRAIGHT-LINE RESULTS
Downforce is the load the wing generates. Drag is the aerodynamic cost of producing it. Aerodynamic efficiency is the ratio of downforce to drag (L/D)—the higher the number, the more downforce the wing produces for each unit of drag.
| Wing | Angle | Downforce | Drag | Efficiency (L/D) |
|---|---|---|---|---|
| DF1800 | 2° | 159 lbf / 707.2 N | 16.0 lbf / 71.3 N | 9.92 |
| DF1800 | 7° | 212 lbf / 944.7 N | 23.6 lbf / 105.1 N | 8.99 |
| DF1800 | 12° | 267 lbf / 1186.9 N | 33.2 lbf / 147.9 N | 8.02 |
| DF2000 | 2° | 199 lbf / 885.3 N | 19.2 lbf / 85.4 N | 10.38 |
| DF2000 | 7° | 266 lbf / 1181.4 N | 28.4 lbf / 126.4 N | 9.35 |
| DF2000 | 12° | 344 lbf / 1531.4 N | 39.1 lbf / 173.9 N | 8.81 |
Results shown at 100 mph / 161 km/h with large endplate Vengeance. Downforce is displayed as a positive load.
MORE ANGLE. MORE LOAD. MORE DRAG.
At 2°, both DF wings delivered their highest downforce-to-drag efficiency of the three settings tested.
At 12°, both produced their maximum tested downforce, with the expected increase in drag.
That gives you a clear tuning range: run less angle when efficiency matters most, or add angle when you want more rear aero load. Final setup should be balanced with the rest of the car and the demands of the track.
ENDPLATES MATTER.
Compared with the large endplate configuration, the small endplates produced:
- 4% less downforce
- 4% more drag
For maximum aerodynamic performance, the large endplate configuration is the preferred setup.
DOWNFORCE AT ANGLE.
Straight-line airflow isn’t the whole story. The DF wing was also analyzed at 100 mph / 161 km/h, a 12° wing angle and 40° of yaw to evaluate performance under an extreme off-axis airflow condition.
Even at 40° of yaw, the wing remained aerodynamically active and retained approximately 80% of its straight-line aerodynamic efficiency.
That makes the result especially relevant to drift, where the wing has to keep working with the car at significant angle to the airflow.
PRESSURE WHERE IT SHOULD BE.
CFD pressure plots showed the wing maintaining attached flow across the working surface, while the endplates helped reduce pressure spill at the tips and support load across the span.
THE SUPPORTS MATTER TOO.
The DF supports were sculpted as part of the aerodynamic development, not treated as an afterthought. CFD showed that support shape has a direct effect on the airflow reaching the underside of the wing.
The original support geometry created more disturbance across the wing’s underside low-pressure surface.
The revised DF supports reduced that disruption, helping the wing generate downforce with less unnecessary drag.
TUNE IT TO THE CAR.
You don’t need a full aero package to put the DF wing to work, but adding meaningful rear downforce will change the car’s aerodynamic balance. The adjustable wing angle lets you tune rear aero load to the car, the track and how you drive it.
For a first aero upgrade, 2° offers the highest aerodynamic efficiency of the settings tested and is a strong starting point. Add angle when you want more rear downforce, then tune the setup around how the car responds.
Whatever setting you choose, the trunk, brackets and mounting structure must be capable of carrying the aerodynamic load.
CFD PRESSURE VIEWS
Additional CFD views show how pressure is distributed across the complete wing assembly, including the upper surface, underside, supports and endplates.
Aerodynamic development and CFD analysis by Wavey Dynamics, using the Bramble CFD platform.
CFD figures are simulation results under the stated conditions. Actual performance may vary depending on vehicle setup, mounting position, wing angle and airflow.
