Rubber automotive engine mounts play a crucial yet often overlooked role in sportscars. These mounts absorb engine vibrations, ensuring smooth operation and stability while driving at high speeds. However, as these mounts age and degrade, they can become a source of significant issues, impacting both performance and safety. In this blog, we delve into the intricacies of rubber automotive engine mounts in sportscars, especially the Elise and Exige, exploring their degradation process and the potential consequences.
Understanding Rubber Engine Mounts:
Rubber engine mounts serve as a buffer between the engine and the chassis, dampening vibrations generated during operation. In sportscars, where precision and performance are paramount, these mounts must withstand rigorous conditions, including high speeds, abrupt acceleration, and sharp cornering.
The 111 platform has the powertrain mounted transversely AND features a cable-actuated, manual, transmission. Under aggressive driving, powertrain movement is quite violent and can cause the shifter cables to perform poorly making finding a specific gear difficult. This naturally happens at the most inopportune times!
Factors Leading to Degradation:
Several factors contribute to the degradation of rubber automotive engine mounts in sportscars:
Heat Exposure: The engine compartment of sportscars often experiences elevated temperatures, leading to accelerated deterioration of rubber components. The 111 is mid-engined which can lead to hotter engine bay temps.
Vibration and Shock: Sportscars, especially those designed for racing, subject engine mounts to intense vibrations and shocks, hastening wear and tear.
Chemical Exposure: Exposure to oil, fuel, and other chemicals commonly found in the engine bay can degrade the rubber material of mounts over time. This is probably the smallest contributor to mount failure in the 111 platform.
Age: Like all rubber components, engine mounts undergo natural aging processes, becoming less resilient and prone to failure as they grow older.
Signs of Deterioration:
Identifying signs of rubber engine mount degradation is crucial for preventing potential issues. Common indicators include:
Increased Vibration: As mounts lose their damping capability, drivers may notice amplified engine vibrations, especially during acceleration or idling.
Excessive Engine Movement: Worn mounts fail to provide adequate support, allowing the engine to move excessively, potentially causing damage to surrounding components.
Clunking or Thumping Noises: Degraded mounts may produce audible noises, such as clunks or thumps, particularly when shifting gears or traversing uneven terrain.
Visible Wear: Inspection of engine mounts may reveal visible signs of wear, such as cracks, tears, or collapsed sections, indicating the need for replacement.
Consequences of Deteriorated Mounts:
The ramifications of deteriorated rubber automotive engine mounts in sportscars extend beyond mere discomfort. Some potential consequences include:
Decreased Performance: Engine mounts play a crucial role in maintaining optimal drivetrain alignment. Deteriorated mounts can compromise this alignment, leading to decreased performance and responsiveness.
Increased Wear on Components: Excessive engine movement resulting from worn mounts can lead to accelerated wear on adjacent components, such as exhaust systems, drivetrain components, and even the chassis itself.
Safety Hazards: In extreme cases, severely degraded mounts can compromise vehicle stability and control, posing safety hazards, especially during high-speed maneuvers or emergency situations.
Upgrade Options?
We identified performance problems early on with the 111 platform that were mount related. We started working on solutions many moons ago:
HERE. As a result, we developed three levels of mount upgrades based on the desired performance - with corresponding trade-offs. The biggest tradeoff is the added vibrations from mounts.
NVH (Noise, Vibration and Harshness) is a criteria that must be considered with mount upgrades. The options we developed help to restrict powertrain movement to improve both throttle response but also shift action. The increase in NVH with each option varies.
This is the solution we recommend for street cars that get driven aggressively. The are inserts that are added to existing mounts to reduce their movement. This solution can alos be used if you notice that your stock mounts are getting worn or have small tears in them. We covered this issue in a Blog post:
HERE. They can extend the life of your mounts. We recommend them for cars that are 80/20 cars - Street/Track.
This solution replaces two mounts, front and rear with new mounts with stiffer bushings. The NVH penalty with this kit is not acceptable for a car run on the street most of the time. As a result, we consider this a 20/80 solution - Street/Track. It is really for cars that are driven on the street, just to get it to the track.
This is a Race solution for cars that are trailered to the track. It provides the best powertrain rigidity but the biggest NVH penalty. We consider this a 100/0 solution!
Conclusion:
We are seeing mounts on the 111 platform that are starting to age. We're hearing from clients who are having more shifting related issues. This only makes sense as these cars were introduced back in 2005! The various solutions we offer can help improve performance but also extend the life of existing mounts.
Regular inspection and timely replacement of worn mounts can mitigate potential issues, ensuring that these high-performance vehicles continue to deliver thrills on the road or track. We don't consider that these parts as consummable bits, but in reality, they will wear out.
