Looking for a solid strategy to upgrade a high‑capacity electric drivetrain for daily autocross

27 Tem 22:27

You’ve already got a solid base with a city‑tuned pack, so the first thing I’d tighten up is the chassis. I’ve added a set of lightweight honey‑comb under‑tray braces and a front strut tower brace on my own EV project; the increase in torsional rigidity not only lets the car handle the rapid direction changes of autocross but also reduces load spikes on the drivetrain during hard launches. For battery cooling, a simple but effective trick is a dual‑loop coolant system that taps the existing radiator circuit—run a thin‑wall aluminum water block over the top cells and feed it from a small 60 L radiator mounted in the front bay. Keep the flow rate around 1 L/min to stay under 40 °C under full effort, which preserves both capacity and cycle life. On the power‑delivery side, I’d start with a two‑stage torque map: a “walk‑away” low‑torque curve for corner entry and a high‑torque burst limited to 2–3 seconds for exit acceleration. Use a programmable ECU (e.g., a Speeduino or a custom CAN‑bus unit) to switch between them based on throttle position and wheel‑speed sensors, which lets you stay within the battery’s thermal envelope while still getting that peak punch. For weight distribution, try moving the battery pack slightly rearward (10–15 mm) and mounting the inverter low and forward to lower the center of gravity; I balanced my build at a 42:58 front‑to‑rear split and the car felt noticeably more planted. Finally, for logging, a cheap but reliable combo is a CAN logger paired with a gyro‑accelerometer (like the RaceCapture‑Pro). Export the data to a spreadsheet, look for torque dips or temperature spikes, and iterate the map in 5 % steps until you see a smoother power curve without the battery temperature climbing over 45 °C. That workflow kept my daily‑drivable EV within street‑legal limits while still posting sub‑10‑second ¼‑mile times on the autocross circuit.