Enhanced No-Load Bias Ratio via its Wave Design Center Pack
One of the known shortcomings of a typical torque biasing differential is its loss of drive (behaving much like an open diff) under zero or near-zero torque conditions (for example, when there is 'no-load' applied through the drivetrain, either at vehicle stationary and/or transition from engine driving vehicle to engine braking and back).
The Wavetrac® differential uses a patent pending design to improve grip in low traction conditions. Precisely engineered, converging / diverging wave profiles are placed on one side gear and its mating preload hub. As the two side gears rotate relative to each other, each wave surface climbs the other, causing them to move apart. This imparts an increased normal force through the side gears, increasing the bias ratio as a function of load. This increase occurs automatically only when conditions find it necessary, and it 'reverts' back to its nominal bias ratio quickly and seamlessly, maintaining optimal drivability and performance at all times. It's like having two differentials in one: you get the benefit of a higher bias ratio when needed without detriment to the car's handling.
Interchangeable Friction Plates Provide Controlled Bias
Here's something else you won't find in any other design:
The Wavetrac® diff's behavior can be altered in the field to suit your needs. It comes standard with carbon-fiber bias plates for the best all around performance. Interchangeable plates using materials with different friction coefficients to fine-tune the bias ratio are sold separately.
These friction plates provide a mechanism to tune the response of the differential as a function of applied torque load. The applied torque load manifests itself as an axial load from the differential pinions into the housing. This axial force is then considered a normal force into the friction plate,
and as a function of the effective coefficient of friction, will provide a resistive torque to the rotational motion of the differential pinions. The resistive torque will add to the resistance of relative rotation of all components within the differential. The resistive force, however, is non-uniform since it is a function of the axial load from the differential pinions. The unbalance of the resistive torque will manifest as non-uniform energy absorption within the differential causing a bias ratio.
Superior Design, Materials, and Construction
Designed from a clean sheet, the new Wavetrac® Differential brings current gear technology to the market. Internally, its gear tooth forms are optimized for strength and improved oil film retention over competitive designs. Our gear package is smaller, reducing overall mass, yet is more durable. Attention was also paid to the side gear/axle interface, putting as much material thickness as possible in this critical area - most important when power levels get high.
Each Wavetrac® Differential is crafted from the highest quality materials available. The internal gears are made from high strength 9310 alloy steel. The diff bodies are machined from case hardened steel billet. To complete the package, every Wavetrac® differential is built exclusively using high quality, high strength fasteners from ARP®, the world leader in fastener technology.
Since the factory differential and ring gear are riveted together at the factory,
when installing a Wavetrac® differential or a new ring and pinion in your 020, 02A, 02J
or 02M transmission, you must drill out the rivets and replace them with special bolts
and nuts. These are available from Volkswagen and also other aftermarket sources.
After losing confidence with the quality and/or having been dumbfounded by
the outrageous prices for these parts from these sources, we at Autotech now offer
what we know to be the highest quality bolt sets available for your differential installation.
Produced for us by ARP, the world leader in high grade fasteners, our bolt
kits are made from certified CHQ 8740 Chrome Moly material (rated well above
aircraft quality). Threads are rolled after heat treat ensuring the finest
threads that can be torqued more accurately without binding. The splines on
our bolts are sized correctly for the crucial press-fit into the differential
flange. We use ARP 12-point nuts rated at 180,000 psi or better. Bottom line: you
won't find a better bolt set. You're buying the best differential available...
now buy the best bolts to hold it!
For more information, please contact our tech department at (949) 240-4000
02A/02J Differential Installation Kit
Autotech has made it easy to install your new Wavetrac® ATB differential.
Using ARP's superlative bolt kit as the basis, we have sourced the necessary end
cover gasket, carrier bearings, speedometer drive gear and o-rings from
Volkswagen required for a successful installation. Save time and money!
Silkolene produces some of the finest performance lubricants available anywhere.
Silkolene Silktran SYN5 75W/90 Gear Oil is a fully synthetic high-performance gear
oil designed for use in manual transmissions. Silkolene SYN5 utilizes the
latest and most thermally stable components available and meets the most
stringent gear oil performance criteria. Meets both GL4 synchromesh and GL5
specifications. Is also suitable
for all types of driving conditions, including racing. 2 liters are recommended
for transmission fluid replacement.
One of the known shortcomings of a typical torque biasing differential is its loss of drive (behaving much like an open diff) under zero or near-zero torque conditions (for example, when there is 'no-load' applied through the drivetrain, either at vehicle stationary and/or transition from engine driving vehicle to engine braking and back).
The Wavetrac® diff's behavior can be altered in the field to suit your needs. It comes standard with carbon-fiber bias plates for the best all around performance. Interchangeable plates using materials with different friction coefficients to fine-tune the bias ratio are sold separately.
Since the factory differential and ring gear are riveted together at the factory,
when installing a Wavetrac® differential or a new ring and pinion in your 020, 02A, 02J
or 02M transmission, you must drill out the rivets and replace them with special bolts
and nuts. These are available from Volkswagen and also other aftermarket sources.
