Megan Racing Motor Mounts 240sx

The Nissan 240SX, a darling of the drift and tuner communities, is renowned for its lightweight chassis, robust SR20DET or KA24DE engine, and inherent modifiability. One area ripe for improvement is the factory motor mounts. While adequate for a stock vehicle, these rubber mounts quickly become a weak point when power is increased or the car is subjected to the rigors of performance driving. Megan Racing, a well-known aftermarket manufacturer, offers a popular alternative: their line of motor mounts specifically designed for the 240SX. This article will delve into the technical aspects of these mounts, exploring their design, materials, installation considerations, and performance benefits.

Understanding Stock 240SX Motor Mounts: A Critical Weakness

Before examining the Megan Racing offerings, it's essential to understand the limitations of the original equipment manufacturer (OEM) mounts. These mounts typically consist of two main components: a metal bracket bolted to the engine block and chassis, and a vulcanized rubber bushing sandwiched between them. This rubber serves a crucial purpose: isolating vibrations and reducing noise transmitted from the engine to the cabin.

However, the soft rubber also introduces several drawbacks:

Excessive Engine Movement: Under acceleration, deceleration, and cornering, the engine can shift significantly within the engine bay. This movement can lead to imprecise throttle response, inconsistent handling, and even clearance issues with exhaust manifolds or other components.
Power Loss: Engine movement absorbs energy that could otherwise be used to propel the vehicle forward. This is particularly noticeable in high-horsepower applications.
Durability Issues: Over time, the rubber degrades due to heat, oil exposure, and constant stress. This leads to cracking, softening, and eventual failure of the mount.

The OEM mounts are engineered with a compromise in mind - comfort over performance. For a daily driver, this is acceptable. But for a modified 240SX used for drifting, track days, or spirited street driving, these compromises become significant limitations.

Megan Racing Motor Mounts: A Stiffer Solution

Megan Racing motor mounts address the shortcomings of the OEM mounts by employing a stiffer material in the bushing. Instead of soft rubber, they typically utilize polyurethane (PU) or a combination of PU and steel. This fundamentally changes the characteristics of the mount:

Materials and Construction:

Megan Racing usually offers different durometers (hardness ratings) of PU bushings. The higher the durometer, the stiffer the bushing. A stiffer bushing will transmit more vibration but will also minimize engine movement. Common durometers range from 60A to 80A for street/track use, with higher durometers available for dedicated race cars.

Polyurethane (PU) Bushings: PU is a synthetic elastomer known for its durability, resistance to oil and solvents, and ability to be molded into various shapes. It provides a significantly stiffer alternative to rubber while still offering some degree of vibration damping.
Steel Construction: The metal brackets of the Megan Racing mounts are typically made from high-strength steel, often with a powder-coated finish for corrosion resistance. These brackets are designed to be direct replacements for the OEM units.
Reinforcement: Some Megan Racing mounts incorporate steel inserts or sleeves within the PU bushing to further enhance strength and durability. This is particularly important in high-torque applications.

Design Considerations:

Megan Racing motor mounts are generally designed as direct bolt-on replacements for the OEM mounts. However, some variations might exist depending on the specific model and application. It's crucial to verify compatibility before purchasing.

Fitment: Proper fitment is paramount. Incorrect installation can lead to vibration issues, premature wear, or even damage to the engine or chassis.
Preload: The mounts should be installed with the correct preload (the amount of compression applied to the bushing when the mount is tightened). Incorrect preload can affect the mount's performance and longevity.
Clearance: After installation, it's essential to check for adequate clearance between the engine and surrounding components, such as the exhaust manifold, firewall, and intake. The reduced engine movement provided by the stiffer mounts helps maintain these clearances, but it's still important to verify.

Performance Benefits of Megan Racing Motor Mounts

Switching to Megan Racing motor mounts offers several performance advantages:

Improved Throttle Response: By minimizing engine movement, the mounts allow for more direct power transfer from the engine to the drivetrain. This results in a sharper and more responsive throttle.
Enhanced Handling: Reduced engine movement improves the car's overall handling characteristics. The engine no longer contributes to body roll or weight transfer during cornering, leading to a more stable and predictable driving experience.
Reduced Wheel Hop: In high-horsepower applications, excessive engine movement can contribute to wheel hop (the bouncing of the rear wheels under acceleration). Stiffer motor mounts help to control this movement, improving traction and acceleration.
Increased Durability: Polyurethane bushings are generally more durable than rubber, especially when exposed to heat, oil, and solvents. This translates to a longer lifespan for the motor mounts.
Reduced Drivetrain Stress: By limiting excessive engine movement, stiffer motor mounts can reduce stress on other drivetrain components, such as the transmission and differential.

Installation Considerations and Potential Drawbacks

While the benefits of Megan Racing motor mounts are clear, there are also some potential drawbacks to consider:

Increased Vibration: Stiffer motor mounts transmit more vibration from the engine to the cabin. This can result in a harsher ride and increased noise levels, especially at idle. The severity of this effect depends on the durometer of the PU bushings used.
Difficulty of Installation: Installing motor mounts can be a challenging task, requiring specialized tools and techniques. It's often recommended to have the installation performed by a qualified mechanic.
Potential for Noise, Vibration, and Harshness (NVH): While reduced engine movement is a positive for performance, it translates to more NVH. Choosing the right durometer is key to finding a balance. A very stiff mount may be uncomfortable for a daily driver.
Cost: Aftermarket motor mounts are typically more expensive than OEM replacements.

Installation Tips:

Before beginning the installation, consult a repair manual or online resources for specific instructions for your 240SX model. Here are some general tips:

Safety First: Always disconnect the battery before working on the engine or drivetrain. Use jack stands to securely support the vehicle.
Support the Engine: Use an engine support bar or a jack with a wood block to support the engine's weight while removing the old mounts. Failure to do so can damage the engine or other components.
Penetrating Oil: Apply penetrating oil to the motor mount bolts several hours before attempting to remove them. This will help to loosen any rust or corrosion.
Torque Specifications: Tighten the motor mount bolts to the correct torque specifications. Overtightening can damage the mounts or the engine block.
Alignment: Ensure that the engine is properly aligned after installing the new mounts. Misalignment can cause vibration issues and premature wear.

Choosing the Right Durometer: Balancing Performance and Comfort

The key to selecting the right Megan Racing motor mounts lies in finding the right balance between performance and comfort. Consider the following guidelines:

60A Durometer: A good compromise for street/track cars. Offers a noticeable improvement in performance over OEM mounts with minimal increase in vibration.
70A Durometer: Suitable for more aggressive street/track cars. Provides a significant reduction in engine movement but may result in a noticeable increase in vibration.
80A Durometer and Higher: Designed for dedicated race cars. Offers the maximum reduction in engine movement but will transmit a significant amount of vibration to the cabin.

Conclusion

Megan Racing motor mounts offer a significant upgrade over the OEM mounts in a 240SX, providing improved throttle response, enhanced handling, and increased durability. However, it's crucial to carefully consider the potential drawbacks, such as increased vibration, before making a purchase. By understanding the technical aspects of these mounts and choosing the appropriate durometer, enthusiasts can tailor their 240SX's performance to their specific needs and preferences. Upgrading your motor mounts provides a noticeable difference in the overall feel and responsiveness of the vehicle, making it a worthwhile modification for any serious 240SX enthusiast looking to improve their driving experience.