RC car Tuning

Nitro engines power many high-performance, radio-controlled (RC) model cars, along with offroad vehicles and monster trucks. A nitro engine uses a fuel blend of 10 to 30 percent nitromethane, an exceptionally volatile fuel, and methanol. Most nitro engines are two-stroke engines that use a fuel-oil mixture featuring 12 to 25 percent oil content. Many of them operate at up to 20, 000 rotations per minute (RPM), which is a very high number for an internal combustion engine. Consumers should know how to tune a carburetor properly before they modify an RC nitro engine. A combination of high fuel volatility and engine speeds make proper tuning essential for developing reliable engine power. Hobby shops, internet retailers, and online marketplaces like eBay sell RC nitro engine parts.

RC Nitro Engine Carburetor Tuning

Proper carburetor tuning is essential for the good performance of an RC nitro engine. An improperly tuned carburetor may prevent the engine from starting, idling, or maximizing its power output. You can get the most out of your RC nitro engine by performing a baseline tune, and adjusting the low-speed needle and high-speed needle to maximize performance. Enthusiasts need a screwdriver set to adjust carburetor needles.

Baseline Carburetor Tuning

Baseline carburetor tuning is the first step of tuning an RC nitro engine for peak performance. While baseline carburetor settings vary among models, there are some general rules for establishing a baseline tune. Turn the low-speed needle one turn counterclockwise to open it. Then turn the high-speed needle two to three turns counterclockwise. Start the engine.

If the engine is new, follow the break-in procedure recommended by the manufacturer. In most cases, you should adjust the low-speed needle to provide a rich fuel-oil mixture because most break-in procedures require engines to idle for long periods. Turn the low-speed needle past one turn counterclockwise to richen the fuel-oil mixture.

High-speed Needle Tuning

The high-speed needle of the carburetor controls the fuel-oil mixture from mid to high RPM. The goal of tuning the high-speed needle is the delivery of maximum top-end performance. Tune the carburetor for the racetrack, and find out the performance of the RC car by driving it on the track. Measure the time it takes for the car to cover the longest straight section of the track. Turn the high-speed needle counterclockwise to richen the fuel-oil mixture until performance stops improving. RC nitro engines reach high RPM on racetracks with long straight sections, so you should slightly richen the fuel-oil mixture to make sure the engine is lubricated properly. This improves engine durability by preventing premature engine wear.

Low-speed Needle Tuning

The low-speed needle of the carburetor controls the fuel-oil mixture from low to mid RPM. The purpose of tuning the low-speed needle is to optimize acceleration. Two methods work well for tuning the low-speed carburetor needle: the pinch method and on-track tuning. To use the pinch method, start with the engine at normal operating temperature. Pinch the fuel line connecting the fuel tank to the engine. If the engine stalls in less than three seconds, richen the fuel mixture by turning the low-speed needle counterclockwise. If the engine stalls after five seconds or more, lean out the fuel mixture by turning the low-speed needle clockwise. The engine should stall after three to four seconds.

On-track tuning is ideal because you can tune the engine under racing conditions. To tune the low-speed needle on-track, idle the engine at the starting line for about 10 seconds. Next, accelerate the RC car repeatedly, adjusting the low-speed needle between acceleration runs. The aim is to achieve peak acceleration without bogging or hesitation at launch.

Many factors affect nitro engine tuning: engine wear, racetrack characteristics, driving style, weather conditions, and engine modifications. Enthusiasts must tune the engine whenever a significant change occurs in one or more of these factors. For example, you must adjust the carburetor whenever you install a new glow plug in an RC nitro engine, especially if it has a different temperature range than the one that you replaced.

How to Buy RC Nitro Engines on eBay

RC nitro engines require proper tuning in order to perform well on a consistent basis. You should know how to tune a carburetor properly to get the most from the engine of your RC car. In particular, you must know how to establish a baseline tune and adjust the high-speed and low-speed needles to increase performance and improve drivability. Go to the search bar on any eBay web page, type in relevant keywords such as "RC Nitro Motor, " and click the search button to find a wide range of RC nitro engine parts. Use filters like Brand or Part to limit the search results. eBay Stores also sells nitro engine parts for RC cars.