|A good friend of the shop Jimmy Loushin, upon hearing about our Mk4 Density Mount release, started snooping around the shop with his hands in his pockets, flashing puppy dog eyes at us...how could we resist. "Alright Jimmy, pull your car in the back, Street Density it is!"
Jimmy's Street Beast Chick Magnet
A shot of Jimmy's mounts before they were...mounted
I would highlight the install of the mounts, but our tech Mike took about 30 minutes to install all 3 as per the factory procedure - nothing special. Since 034Motorsport Density Line mounts are built by an OE manufacturer to our specifications, they fit and are finished just like factory products. No slotting of holes, no untested designs, we simply take what the factory did, and make it better suited to performance applications.
Our Street Density "Dogbone" Mount Installed. Looks like stock, but looks don't tell the whole story
One grapple with a Density mount will quickly assure you these are not just re-boxed factory mounts, and no poly filling or other tricks of the trade to stiffen up an OE mount. We go right to the source of what makes these mounts resist engine movement - the rubber.
A definition for rubber durometer is as follows: Hardness as a property of rubber is difficult to define except according to the methods used to determine it. These methods measure the resistance of the stock to indentation by the blunt point of a metal rod, ball, or needle. Thus the hardness of rubber can best be described as resistance to indentation. Various instruments measure indentation. The most common instrument used on rubber is the Durometer.
A shot of the 034Motorsport Durometer Tester
A picture of the Durometer being used on a factory mount to determine its "stiffness"
Before we finalize on a given spec for the Street or Track density, OE sample mounts are tested with sample durometer ratings, generally the bigger the number the stiffer the mount. Most OE mounts fall in a 30-45 durometer range, rarely higher than this.
Generally, Street Density mounts are developed to provide minimum drivetrain movement (or slop) with minimum NVH (noise, vibration and harshness). Usually the perfect balance results in a 50-60 durometer range, and a slight noticeable hum at idle and the faintest vibration. Most passengers, when entering the car, wouldn't feel it unless you pointed it out. Street Density mounts are perfect for the daily driven car where comfort and performance are both priorities, and a faster transfer of power is desired. Think of Street Density mounts like a "lowered, stiffer" suspension for your drivetrain.
Track Density mounts are, for all practical purposes, solid mounts, with no concern for comfort or lack-of-vibration - only an unadultered lockdown of the drivetrain. Durometer vary in the 70-90 range, and result in a locked-down, fast reacting, razor sharp drivetrain. You hit the throttle, air rushes into the motor, TQ and HP are produced , transferred to the input shaft of the transmission - and instant power to all driven tires.
The problem with OE mounts is that there is so much softening of the rubber in the mount to prevent NVH, that power delivery is compromised. The time lag between when you hit the throttle and when power is actually transferred can be greatly delayed. Instead of applying power to the ground, the first few rotations of the tire are spent loading up the squishy, high travel mounts. Also, shifts can get sloppy and even can be missed with such great drivetrain movement. Also, hard launches and drag launches cause the drivetrain to load up hard and bounce causing intercooler plumbing, wire harnesses and other components to be stressed, even causing damage to the motor or other ancillaries. We've even seen motors dent the hood !
If you've spent time to modify your exhaust, put on a bigger turbo, chip your car or stiffen up your suspension, don't ignore the performance value of a properly controlled drivetrain. Faster power transfer, more precise handling, safety and longevity are to be gained with a drivetrain mounting system suited to the upgraded performance of your car.
YOU CANT EVEN TELL!