Reference
Universal Brake Duct
Scalable-mouth front brake cooling duct with a fixed hose collar. Four mounting styles: side zip-tie ears, top zip-tie pads matching the Fusion original, bolt-through tabs, or bare.
Printing it
- Material
- PETG / ASA
- Minimum wall
- 1.6 mm
Print mouth-down on the inlet rim with supports only under the collar. Brake ducts see radiant heat from the disc; PLA will sag.
Parameters
Every number this part is generated from. The geometry is built from these rather than scaled from a fixed model, so a value you can measure off your own car is a value you can type in.
Inlet mouth
| Parameter | Range | Default | What it does |
|---|---|---|---|
| Mouth width | 70–180 mm | 110 mm | Outer envelope of the inlet, measured across the car. |
| Mouth height | 30–120 mm | 65 mm | |
| Mouth squareness | 2–8 | 5 | 2 is a pure ellipse, 8 is nearly rectangular. Squarer mouths capture more area behind a bumper aperture; rounder ones are stiffer. |
| Inlet lip depth | 0–15 mm | 6 mm | Rolled entry lip. Adds stiffness to the rim and tolerates yaw before the inlet stalls. 0 disables it. |
Duct path
| Parameter | Range | Default | What it does |
|---|---|---|---|
| Duct length | 60–220 mm | 130 mm | |
| Collar rise | -60–60 mm | 25 mm | Vertical offset of the collar relative to the mouth axis. |
| Collar lateral offset | -60–60 mm | -30 mm | Sideways offset of the collar. Negative is a right-hand-side part. |
| Wall thickness | 1.6–4 mm | 2.4 mm |
Hose collar
| Parameter | Range | Default | What it does |
|---|---|---|---|
| Hose inner diameter | 51 mm (2 in) · 63 mm (2.5 in) · 76 mm (3 in) · 89 mm (3.5 in) | 51 mm (2 in) | Nominal inner diameter of the ducting hose the collar plugs into. 51 is 2 inch, 76 is 3 inch. The mouth has to swallow the collar, so the bigger sizes need a bigger mouth than the default: 76 mm wants a mouth around 88 x 76, and 89 mm wants about 103 x 89. |
| Collar retention barb | On or off | On | Sawtooth ridge that stops ducting hose pulling off. Turn it off for a silicone coupler, which wants a plain parallel spigot. |
Mounting
| Parameter | Range | Default | What it does |
|---|---|---|---|
| Mounting style | Side ears, zip-tie slots · Top pads, zip-tie slots · Side tabs, bolt-through · None | Side ears, zip-tie slots | Ears reach outboard from the duct sides. Pads sit on the duct's upper surface and match the Fusion original. Tabs take bolts instead of straps. |
| Tab bolt size | M5 · M6 · M8 | M6 | Used by the bolt-through tabs only. Tab width follows the bolt. |
| Strap positions | 2–8 | 4 | Number of zip-tie slots per ear or pad. The Fusion original has 4. |
| Strap pitch | 8–24 mm | 10 mm | Spacing between strap positions. Slot width is fixed at 5.5 mm to clear a 4.8 mm zip tie, so the pitch sets how much web is left between them. |
| Pad spacing | 20–90 mm | 38 mm | Centre-to-centre of the two top pads. Used by the top-pad mounting only; 38 mm matches the Fusion original. |