Engine Mount Degradation

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.

• sportINSERTS

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.

• TRACKmounts

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.

• RACEmounts4

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.

Evora Track Car TLC

One of our clients requested that we bring in his Evora for a little TLC. His clutch was not disengaging which prompted this work. Clutch replacement is a 40hr job on an Evora so he asked us to take care of a few other items at the same time.  This blog lists some of the items we found and fixed or upgraded.  

One key client request was that we make his rear clam easier and quicker to remove. The rear clam has to be removed along with the engine to do a clutch replacement on the Evora. This will be the second time the engine has been out of this particular car and the owner wanted to reduce the costs of any future service. As this car lives at the track, this is a smart move.


This was the first time we worked on this car so we needed to get a good handle on it's condition.  As we dove into the car we found the following:

• Broken clutch
• Loose exhaust
• Missing rear engine mount bolt (!!)
• Broken engine mounts (left and rear)
• Broken/heat damaged shifter cables 

Here's an Evora with it's heart removed. Look familiar?

We found several other issues, some of which were mentioned in our last blog entry. At some point, the rear engine mount bolt fell out, and the resulting excessive engine movement caused or contributed to all the other problems (besides the cables). With the knowledge that this car is now a dedicated track car, we decided to take the opportunity to do some worthwhile upgrades including simplifying and adding lightness - who needs AC in a track car - right? 

First order of business was removing the clam and engine. One of those things that is easier said than done. This is definitely a time intensive job.  We came up with some ideas to speed up reinstallation/removal.  Since the client still wanted to keep the stock rear hatch (for now), we were limited in some of our ideas.  Certain items, like the battery was relocated to the passenger compartment to help speed up the R&R process.  

Broken disk = no bueno

The first thing we swapped out was the clutch.  The original clutch failed because a spring broke free from the disk.  We took this opportunity to visit our clutch supplier to discuss options for the Evora.  We landed on a couple of different balanced clutch/flywheel packages that we think will work well on Evoras.

New Clutch/Flywheel Bits

The clutch we chose is a heavy duty solution but the pedal effort is just as light, if not lighter than stock. The hub plate is much stronger and should retain the springs very well.  We also threw in an aluminum lightened flywheel for good measure. This combination should last a long time, which is a good thing considering how involved a clutch replacement is on this car. 

One of the broken mounts.

  When we discovered 2 of the 4 engine mounts were in bad shape, we called up our engine mount supplier to try our their upgraded solution. These mounts should be an improvement over the soft stock ones. Reducing engine movement helps with throttle response and shift feel.  They will be available for sale as soon as a few fitment issues are resolved.  We had to modify the mounts to get them to fit correctly. 

New TRANScables

The shift feel on this car was also terrible. One push of the gear lever let us know immediately that something was not right. After a very short investigation, it was apparent that the cables were causing excessive drag. We think that the stock cables are being damaged by high engine bay temperatures and the housings are shrinking around the cables. The cable housing/sheath was also cracked and broken near the ends (see pic).  


Since we have had great performance from our TRANScables for the Elise/Exige, we contacted our supplier to make us a prototype set for this Evora. The difference is astounding. The improvement in feel is apparent even when compared to the other Evora we currently have in our shop. That car has good cables and the shift quality is fine, but these cables bring it to another level. Expect to see this on our site soon as well.

Another interesting area that we were able to study is the actual shifter mechanism.  It is very similar to the Elise shifter which means our shiftR111 should likely fit with some minor tweaks.  First we need to get it released and running on the Elise/variants.

Wiring was a bit lack luster in this car. The interior was gutted and caged so much of the wiring was exposed.  There was so much unsecured wiring that it gave us anxiety. Wiring failures are a very common problem on race cars and that simply does not need to be the case. A few well placed zip ties or p-clips go a long way to preventing damage or failure.  Anyone who has ever had to trace a wiring related issue will agree that preventing an electrical failure is almost always easier than fixing one.

More details on the modifications we did to the bodywork on the next blog.... 

Engine Mounts

In early 2007 we began working on a solution for the severe engine rocking inherent in the Elise/Exige. Shifting problems and exhaust failures can clearly be attributed to this excessive motion - it has also maligned a LIDbone or two. I made the following post last summer:

We've been vexed by the large engine movement in our cars. To address this
issue, we're experimenting with transmission mounts. These direct replacements
have stiffer polyurethane bushings that reduce engine/transmission movement,
which results in more precise shift performance and better throttle response.
The pictures below show our second generation prototypes that we've tested in
our cars. As it turns out, we have much more work to do to insure that it is a
solution that can work for most of the community. We'll keep at the R&D
because this is one problem we aim to sort! No ETA on the final product....

Unfortunatley these caused far too much cabin vibration. I think most NVH engineers at Lexus would have had a coronary if they drove our car with these two mounts. Without question they improved the shifting action of the Spyder by dramatically reducing the rotation. But the high levels of shake & rattle sent us back to the drawing board for street driven cars.

Earlier this year we sorted a new solution which comprised of metal inserts that took up the recesses in the stock rubber mounts. It was another clever idea from our friends at BurkeBuilt but it turned out to be too expensive to produce. We tested this solution on track and it worked very well.

Enter Innovative Mounts: We've now found a solution that should meet our needs for dramatically reduced engine rotation AND minimal vibration into the cabin. Innovative Mounts has been building mounts for the sport compact market for over 10 yrs. Their kit includes mounts for all 4 locations. Though we considered changing only the front and rear mounts, Tim@Innovative highly discouraged us. They have found this will create more stress on the remaining 2 mounts as well as transmit too much vibration. One of the key features of their PUR bushing is the tapered end design which helps reduce vibration transmission through the attachment points.

We will be testing a set on our car this week or next. We expect to have them available in 2 flavors of stiffness: Street & Track.