BMW Engine & Transmission Mount Compounds and Applications

Engine and transmission mounts are essential components within a vehicle’s driveline even though they are frequently overlooked when it comes to performance. Not only are they responsible for helping support the engine and transmission but are also responsible for the efficiency of power delivery and responsiveness when accelerating, downshifting and upshifting. Classic BMW’s were all manufactured with rubber as the main component for both engine and transmission mounts therefore making them a wearable component. As they start to age and break down, so does the car’s performance. One of our specialties here at Condor Speed Shop is manufacturing engine and transmission mounts that will not only last far beyond the life of oem rubber, but will also outperform it. In this article we aim to shine a light on the different compounds of engine mounts available and their usability and performance potential in everything from a street/show car to a full-on caged race car. 

One of the first things to consider when purchasing a new set of engine or transmission  mounts, particularly aftermarket/performance varieties, is the mount’s compound and density. You will see on the chart above that there is a range of variety for aftermarket mounts and how they compare to most oem/stock options. Generally speaking, the more dense and harder the material, the greater the performance due to less power being absorbed by flex and compression. Alternatively, the softer the material, the closer it is to the rubber/oem spec, and the more “comfortable” it tends to be, offering 0-minimal Noise/Vibration/Harshness (commonly referred to as NVH).That comfort will always come at the expense of lesser performance due to more absorption from the materials. 

Given these circumstances, we at Condor have a few different solutions and three different compounds, all optimized for performance yet also taking comfort and usability into consideration. 

The softest compound we offer is our Polyurethane “VIP” line. These mounts were designed to offer the best of both worlds in terms of performance and comfort. For example, the caged design of our E36/E46 VIP engine mounts have performance capabilities comparable to our solid engine mounts while maintaining a comfort level extremely suitable for everyday driving and commuting. These mounts are made from 80a Polyurethane which is similar in hardness as BMW’s factory Group N mounts, about 30% stiffer than stock rubber. Their performance stems from a well-designed Billet CNC machined housing which surrounds the polyurethane providing reinforcement suitable for high performance driving. When paired with our polyurethane transmission mounts of the same material they will offer everything a customer would want from their engine and transmission mount upgrade. They are designed to sustain some movement of driveline components which help absorb the NVH. This VIP line is also available for many other BMW chassis including the E30, E9x and E34. 

The next compound  available would be our solid/UHMW mounts. These are the best solution for the track and street alike, offering high performance and tolerance with minimal NVH. As you will see on the hardness chart, these mounts fall just a few steps harder than most typical “medium” density polyurethane blends. UHMW is a self lubricating polymer which is capable of handling heavy loads. UHMW mounts are optimal for all track builds and will only yield a small amount of NVH (usually at idle or lower rpm’s). These will improve responsiveness even further and also match the material from which we design and manufacture the rest of our chassis bushings. They are designed to also absorb some of the movement of driveline components but at a higher performing level than the polyurethane. Their affordable price point and wide versatility make them a great double duty mount and they remain the most popular choice for many BMW chassis, including the 1 series, 3 series & 5 series. 

The third and hardest compound which we offer would be our Aluminum “Armageddon” mounts. These are designed to be extremely durable and high performing without comfort in mind. The aluminum can withstand very high power applications and extremely high temperatures from exhausts, turbos, and/or superchargers much like the UHMW. These mounts will stop all engine and gearbox movement which is valuable to road racers who sustain high lateral g forces when cornering. For the full on high-power track car, time attack build, pro level drift car or rally car, these would be ideal. 

It is important to note that these mounts will work best when the densities of the engine and transmission mounts are closely matched. Having the densities that are too far apart would cause additional, unwanted NVH and could also put the mounts under unnecessary stress. For example, if you were to install aluminum Armageddon engine mounts then you would want to pair it with Armageddon transmission mounts as well. Alternatively, our UHMW and polyurethane blends will work well together. In fact, a good way to dial out the minimal NVH caused by upgrading to UHMW mounts is to pair them with polyurethane transmission mounts. In most cases, this will help improve the level of comfort while still optimizing for higher performance. For these reasons, all of our engine mounts are available with the valuable option to simply add transmission mounts of the same or similar densities when purchasing. 

With higher performance usually comes higher temperatures under the hood. Particularly turbo and supercharged cars can produce excessively hot exhaust temperatures which are usually positioned close to one and sometimes both engine mounts. While our mounts are proven to withstand high temperatures, it is recommended to utilize our heat sleeves to assist in deflecting some of that heat away. This is a simple and common application for both street and race cars, and it will also add some visual flare under the hood as well. 

Engine and transmission mounts will always be one of the first places drivers will go to help accommodate any modifications they plan to make. Our polyurethane mounts are optimal for any OEM Plus style build while our UHMW mounts are tried and true to hold up against heavy driveline abuse from aggressive track driving and drifting, all while maintaining a level of comfort suitable to daily driving. 

The support for those two major driveline components is crucial and the proven quality and high performance that we at Condor consistently achieve is what your BMW deserves. For more information, questions and inquiries please visit our home page or reach out to us directly at support@condorspeedshop.com.