Building a Vehicle Telemetry Logger That Fits the Car, Not Just the Bench

A race engineer finds that a vehicle telemetry logger works on a lab bench but cannot fit inside the car. The installation space is bounded by the center tunnel, shifter linkage, and seat rail. The logger must capture suspension travel, IMU, and CAN data without blocking service access.

The first mock-up covered an access cap and pressed against the driver's boot when the seat moved forward. The board could record suspension travel, inertial movement, GPS position, and vehicle CAN data, but the test crew could not install it without changing the cockpit. The race engineer's issue was not a missing sensor. It was a complete logger designed around a bench-sized mental model.

Start from the installation envelope

The race engineer measured the available volume with the seat at both ends of its track. The logger needed 146 millimeters of width, 88 millimeters of depth, and 42 millimeters of height. He marked the shifter cable path, the access cap, two existing M6 rail points, and the route to the car's 12 V service feed. The crew wanted to connect four linear suspension sensors without routing their leads past the driver's feet.

The board used an STM32H743, a BMI088 inertial sensor, an ADS131M08 eight-channel converter, a TJA1051 CAN transceiver, and a MAX-M10S GNSS module. Four analog channels accepted suspension travel sensors; the remaining ADC inputs were available for brake pressure and steering position. A six-layer, 93 by 61 millimeter board separated the sensor inputs from the GNSS antenna feed and switching supply.

The race engineer imported the car's center-tunnel STEP model, the seat rail, and the gear-linkage envelope. The Flux agent built the schematic and board layout from the logger requirements, checked datasheets and part availability, and kept the BOM current. The race engineer reviewed the ADC inputs, CAN termination, and sensor connector pinout before accepting the first placement.

Find a board position the driver never has to negotiate

The chassis engineer proposed two mounting options: above the tunnel behind the seat or beneath the seat rail. The first position blocked the access cap. The second cleared the seat at every adjustment and left the cable connectors facing the rear bulkhead. The race engineer selected the rail location and asked for two slotted mounting ears rather than drilling the body.

The case used a 6061 aluminum base with a 2-millimeter cover and an internal heat spreader. Four M4 standoffs carried the board, while two rubber isolators connected the enclosure to the seat-rail bracket. A removable end plate exposed the M12 sensor connectors, USB-C service port, GNSS antenna connector, and CAN lead. The board-to-lid clearance had to remain above 1.5 millimeters at the tallest component.

In the first 3D assembly, the GNSS antenna connector faced the seat-belt buckle and the sensor plugs pointed toward the shifter cable. The race engineer rotated the board 180 degrees, then shifted the GNSS module toward the rear edge. The cable bend now stayed below the rail, and the logger's access cap remained clear. An X-ray view showed the BMI088 near the center of the case, aligned with the car's longitudinal axis.

The mechanical engineer revised the bracket to use the existing M6 seat-rail points. A 3-millimeter CNC-cut plate carried the enclosure, with two 6-millimeter slots for adjustment. The team checked bracket deflection and the isolator locations under road vibration. The race engineer asked for a recessed end-plate lip so a tool would not strike the M12 connectors during service.

Three requests from the cockpit fit review

Design a race telemetry logger for suspension travel, three-axis motion, GNSS, and CAN. Keep the enclosure inside the 146 by 88 by 42 millimeter space under the seat rail and leave the access cap clear.

Place the STM32H743, BMI088, ADS131M08, TJA1051, and MAX-M10S on a 93 by 61 millimeter six-layer board. Preserve four suspension inputs, keep the IMU centered, and face the sensor connectors toward the rear bulkhead.

Use the imported center-tunnel and seat-rail STEP models to check the enclosure. Keep two M6 mounting points, leave 1.5 millimeters above the tallest component, and show the connector bends beside the shifter cable.

The logger fit the installation plan

The race engineer and the chassis engineer reviewed the board and mount in an afternoon. They checked the GNSS connector, CAN lead, sensor plugs, access cap, and seat movement in the assembled model. Circuit simulation covered the power input and sensor conditioning. Design rule checks covered the six-layer board before they prepared manufacturing files.

The logger's electronics used the STM32H743, BMI088, ADS131M08, TJA1051, GNSS module, protected 12 V input, USB-C service port, and four suspension inputs. The mechanical package included a CNC aluminum base, cover, heat spreader, end plate, M12 connectors, rubber isolators, and slotted seat-rail bracket. The crew received the Gerbers, BOM, pick-and-place data, wiring map, and STEP models for the case and mount.

The test crew installed the logger without changing the cockpit. The access cap opened, the seat moved through its adjustment range, and the connectors faced away from the shifter. The race engineer added the bracket drawing to the car's setup notes so the next engineer would use the same rail points. The logger could now collect data in the actual location that had shaped its design.

The team had learned that fitting a board was only part of vehicle integration. The device needed to coexist with seat motion, service openings, cable routes, vibration, heat, and driver access. Reviewing those mechanical boundaries alongside the circuits prevented a second board order for a logger that still could not fit.

A race-car logger fit checklist

• Measure the installation zone with seats, linkages, and service covers in working positions.
• Define sensor channels, CAN signals, power, GNSS, and cable exits.
• Place the IMU according to the vehicle axes and intended data analysis.
• Check antenna, connector, component-height, and cable-bend clearances in the enclosure.
• Review bracket stiffness, isolator location, heat path, and service access.
• Export the board and complete mount assembly from the same approved revision.

Start your project at flux.ai