# Designing a Custom Traction Control Unit and Its Engine-Bay Housing motorsport shop builds a wheel-speed controller with a sealed aluminum case and engine-bay bracket. Written by [Matthias Wagner](https://www.flux.ai/natarius) Published Oct 2026 - 5 min read ![Designing a Custom Traction Control Unit and Its Engine-Bay Housing](https://www.flux.ai/p/assets/blogs/custom-traction-control-unit-engine-bay-housing/main.webp) A motorsport shop is building traction control for a classic performance coupe. The controller must read four wheel-speed sensors and send a correction request over CAN, but the hot, crowded engine bay has no safe place for a generic track-day box. the shop's small motorsport team had two weekends before its first closed-course shakedown. The hardware lead, the electrical lead, had designed sensors before, but this controller needed to sit close to the engine control connector and survive vibration. The bracket could not cover the fuel-line inspection point. A board that worked on a bench would not prove that the unit could be installed or serviced. ## Start with the vehicle's signals and mounting points The hardware lead traced the four variable-reluctance wheel sensors to the existing loom and noted the differential pairs. The controller needed to condition those signals, read engine speed and throttle data from CAN, and send a torque-reduction request to the engine controller. The system would not switch the brake circuits. The hardware lead documented that boundary before he started the circuit. The board used an STM32G474 controller, two MAX9926 dual-channel VR sensor interfaces, a TJA1051T/3 CAN transceiver, and an automotive-protected 12 V input. A four-layer layout measured 104 by 76 millimeters. The hardware lead separated the sensor inputs from the switched power supply, added test pads for each wheel channel, and placed the CAN connector on the edge facing the bulkhead. The Flux agent developed the schematic and board around the hardware lead's written signal requirements. The hardware lead checked the MAX9926 datasheets against the sensor voltage range and reviewed the CAN termination with the engine controller documentation. The BOM reflected available components. He ran circuit simulation on the protected input and reviewed design rule checks before he approved the first layout. ## The bracket had to respect an old engine bay The mechanical engineer measured the available space beside the left inner wing. The proposed mounting zone sat near the radiator hose and behind a serviceable relay panel. She imported the car's engine-bay STEP model and aligned it with two existing M6 studs. The controller needed to leave 18 millimeters for the hose's full movement and keep the cover screws reachable from above. The mechanical engineer designed a 6061-T6 aluminum enclosure with a 3-millimeter base, a 2-millimeter lid, and an IP67 gasket channel. The board sat on four M3 bosses. A Deutsch DT-series connector faced the bulkhead, with a backshell path that cleared the relay panel. The outer bracket used 3-millimeter aluminum plate and two rubber isolators to reduce engine vibration. The first assembly view showed the connector's cable bend crossing the coolant hose at full travel. The hardware lead and the mechanical engineer rotated the case 12 degrees and extended the bracket's lower slot. That moved the cable exit toward the inner wing while preserving the two M6 mounting points. An X-ray view revealed a tall input-protection component 1.3 millimeters from the lid. The mechanical engineer raised the lid locally and added a short internal rib to support it. They reviewed thermal behavior at the expected engine-bay ambient temperature and checked bracket strength around the slotted holes. A stainless label plate carried the connector pin map, while a raised case edge protected the seal from tool contact. The board and bracket were checked as one assembly before the machining drawing went to the shop. ## Three requests the hardware lead used for the controller > Design a four-channel wheel-speed controller for a classic performance car. Read the variable-reluctance sensors, receive engine data over CAN, and send a torque request to the engine controller without changing the brake wiring. > Use an STM32G474, two MAX9926 interfaces, and a TJA1051T/3 CAN transceiver on a 104 by 76 millimeter board. Keep wheel-speed pairs away from the switching supply and expose four test pads for sensor review. > Fit the controller beside the left inner wing using the two M6 studs. Preserve 18 millimeters of coolant-hose travel, clear the relay-panel cover, and show the Deutsch connector backshell inside the sealed case. ## The closed-course car received a serviceable unit The hardware lead and the mechanical engineer completed the circuit and mechanical review in one afternoon. They checked the signal map, board layout, case seal, connector angle, and bracket against the imported bay model. The Flux agent kept the board and enclosure changes together; the hardware lead adjusted the sensor labels by hand and signed off on the CAN interface. The finished controller used a four-layer 104 by 76 millimeter board with four VR inputs, an STM32G4, two MAX9926 devices, a TJA1051T/3, and protected 12 V power. Its mechanical assembly included a machined 6061 housing, lid, gasket, M3 board bosses, Deutsch connector, slotted aluminum bracket, and two vibration isolators. The factory received Gerbers, the BOM, assembly files, and STEP models for the case and mount. the shop mounted the unit on the two existing studs and checked the relay panel, hose travel, and service access before the shakedown. The driver could disconnect the controller at the bulkhead connector without opening the sealed case. The track crew verified the wheel-speed channels and CAN messages on a stationary test setup before running the car on course. The hardware lead added the installation angle and connector pin map to the team's service notes. The mechanical engineer kept a removable bracket slot so the case could be adjusted on a second vehicle with a small bay difference. Those details turned the board from a bench experiment into equipment the crew could inspect and maintain between sessions. ## A vehicle-controller review list - Map sensor polarity, power, CAN, and outgoing control signals before layout. - Check wheel-speed front ends and protection components against their datasheets. - Place test points where a technician can reach them after installation. - Import the engine-bay geometry and preserve hose travel and service-panel access. - Inspect the connector backshell, gasket, board height, and bracket in X-ray view. - Review the vehicle interface and test plan before releasing the assembly package. [Start your project at flux.ai](https://www.flux.ai/) ## About the author [Matthias Wagner](https://www.flux.ai/natarius) Founder & CEO at Flux Matthias is the Founder and CEO of Flux, a hardware design platform that's revolutionizing how teams create and iterate on circuits. Find him on Flux [@natarius](https://www.flux.ai/natarius). Let’s start building Build your big idea together with Flux. All you need to do is describe what you want to make, or what problem you want to solve. Flux will work with you to make it a reality. ![Close-up photo of a PCB made with Flux, with an ESP32 module, buttons, and a microSD slot.](https://www.flux.ai/p/assets/blogs/miscellaneous/sidebar-cta-pcb.webp) [Try it Free](https://www.flux.ai/signup) ## Related Content [ ![Line illustration of a long circuit board with a repeating array of identical transistor channels in neat rows inside a rack-mount metal test enclosure with many cable connectors on its front panel](https://www.flux.ai/p/assets/blogs/automating-36-channel-high-voltage-test-rig/main.webp) ### Automating Repetitive Hardware Design: Building a 36-Channel High-Voltage Test Rig 5 Min Read](https://www.flux.ai/p/blog/automating-36-channel-high-voltage-test-rig)[ ![Line illustration of an old audio amplifier product in an exploded view](https://www.flux.ai/p/assets/blogs/design-software-license-lapsed-product-line/main.webp) ### Your Design Software License Lapsed. Your Product Line Doesn't Have To. 5 Min Read](https://www.flux.ai/p/blog/design-software-license-lapsed-product-line)[ ![Line illustration of a circuit board inside an open enclosure where one old chip is lifted out and a new replacement chip lowers into place, with dashed fit lines showing the board still matches the enclosure mounting posts](https://www.flux.ai/p/assets/blogs/revive-product-end-of-life-parts-enclosure-fit/main.webp) ### Reviving a Product With End-of-Life Parts: Redesigning the Board Without Breaking the Enclosure Fit 5 Min Read](https://www.flux.ai/p/blog/revive-product-end-of-life-parts-enclosure-fit)[ ![Line illustration of a small round smart home door sensor in exploded view](https://www.flux.ai/p/assets/blogs/first-founder-smart-home-sensor-board-case/main.webp) ### From Idea to Pre-Orders: How a First-Time Founder Designed a Smart Home Sensor, Board and Case 5 Min Read](https://www.flux.ai/p/blog/first-founder-smart-home-sensor-board-case)[ ![Line illustration of a step sequence of three stages](https://www.flux.ai/p/assets/blogs/breadboard-to-boxed-product-guide/main.webp) ### From Breadboard to Boxed Product: A Step-by-Step Guide 6 Min Read](https://www.flux.ai/p/blog/breadboard-to-boxed-product-guide)[ ![Line illustration of a smart wristband wearable in exploded view](https://www.flux.ai/p/assets/blogs/trade-show-wearable-electronics-enclosure-six-weeks/main.webp) ### How a Startup Built a Trade-Show-Ready Wearable, Electronics and Enclosure, in Six Weeks 6 Min Read](https://www.flux.ai/p/blog/trade-show-wearable-electronics-enclosure-six-weeks) See All (6) ## Let’s start building. Let’s build your idea together. All you need to do is describe what you want to make, or what problem you want to solve. Flux will work with you to make it a reality. [Try it Free](https://www.flux.ai/signup) ![Close-up of a Flux-designed printed circuit board](https://www.flux.ai/p/assets/homepage-v2/mission-visual.webp)