Drag Slash Tuning Pt 2: How to Optimize Gearing
How to pick the best gearing setup for your Drag Slash
Full-size or RC, selecting the correct gear ratio is critical to drag-racing success. In Part 2 of our Drag Slash tuning series, we’ll discuss the two gear ratios included with the car, how they impact performance, and considerations for choosing other gear ratios to suit the way you want to drive your Drag Slash.
Out of the box, the Drag Slash is equipped with a 22-tooth pinion gear and a 76-tooth spur gear for a total gear reduction of 9.38:1 when combined with the transmission’s 2.72:1 gear ratio. This gearing offers a good combination of acceleration, top speed, and battery life for all-around driving and operating your Drag Slash continuously.
Out of the box, the Drag Slash is equipped with a 22-tooth pinion gear and a 76-tooth spur gear for a total gear reduction of 9.38:1 when combined with the transmission’s 2.72:1 gear ratio. This gearing offers a good combination of acceleration, top speed, and battery life for all-around driving and operating your Drag Slash continuously.
The Drag Slash’s standard 76/22 gearing is perfect for all-around driving fun.
For competition with 2S LiPo power, install the optional 29-tooth pinion supplied with your Drag Slash. Extensive testing has determined the 29-tooth pinion offers the ideal mix of acceleration and top speed for a 132-foot track, the standard length for no-prep RC drag racing. Use this gearing for competition only, not continuous driving. Continuous driving with the competition gearing will overheat the power system and may damage the motor, just as a full-size funny car would surely overheat if you tried to drive it in rush-hour traffic.
The included 29-tooth pinion and matching Fixed Gear Adapter are for competition use. The adapter ensures perfect gear mesh and prevents the motor from moving in a crash or impact.
You can experiment with other gear ratios to customize performance or match power delivery to a shorter track. Pinion gears with 25-29 teeth are for speed runs and drag strip use only, not general driving. A pinion with a lower tooth count will help your Drag Slash accelerate faster but reduce its top speed. On tracks shorter than 132 feet, a lower-tooth pinion may offer an advantage. For all-around fun driving with 2S LiPo power, use the 22-tooth pinion. To achiever “lower” gearing (a numerically higher ratio), install a larger spur gear. The manual’s gearing chart makes it easy to see which ratios are safe to use, and which you should reserve for racing and speed runs.
The Drag Slash manual’s gearing chart shows all the pinion and spur gear combinations that can be installed, and indicates which are safe for all-around use and which to reserve for racing or speed runs.
Gear Conservatively for 3-Cell LiPo Power
As mentioned in Part 1, the stock gearing (22-tooth pinion, 76-tooth spur gear) is recommended for 3-cell LiPo power. As an optional step to further safeguard against motor, speed control, and battery heating when using a 3S battery, you can install an 83-tooth spur gear to achieve “lower” gearing. Monitor the motor’s temperature and make certain it does not exceed 200° F (93° C). Overheating can damage and even ruin the motor. You can monitor motor temperature remotely using the Traxxas Link app and your iOS or Android smart device by adding the Traxxas Link wireless adapter to the Drag Slash’s TQi transmitter and installing the 6521 temp sensor on the motor. If your motor exceeds 200° with the gearing you’ve selected, install a pinion with fewer teeth or a spur gear with a greater number of teeth. The gearing chart shows all the combinations that will fit, and their ratios.
As mentioned in Part 1, the stock gearing (22-tooth pinion, 76-tooth spur gear) is recommended for 3-cell LiPo power. As an optional step to further safeguard against motor, speed control, and battery heating when using a 3S battery, you can install an 83-tooth spur gear to achieve “lower” gearing. Monitor the motor’s temperature and make certain it does not exceed 200° F (93° C). Overheating can damage and even ruin the motor. You can monitor motor temperature remotely using the Traxxas Link app and your iOS or Android smart device by adding the Traxxas Link wireless adapter to the Drag Slash’s TQi transmitter and installing the 6521 temp sensor on the motor. If your motor exceeds 200° with the gearing you’ve selected, install a pinion with fewer teeth or a spur gear with a greater number of teeth. The gearing chart shows all the combinations that will fit, and their ratios.
Coming Up in Part 3: Tuning the Sealed Differential
If you missed it, be sure to check out Part 1 here.
