▶ TORSEN DIFFERENTIAL
A Torsen differential belongs to the group of limited slip differentials and is derived from the words Torque and sense.
It is a purely mechanical differential that works without sensors and can often be found in Audi Quattro models today.
It compensates for speed differences and can distribute the torque unevenly. The ratio in which the torque can be distributed between the two sides is called the torque-bias ratio, or TBR for short.
While with the open differential, the torque is either equally distributed to both wheels or lost on the tractionless wheel, the 100 percent limited-slip differential always distributes the power in the same ratio. The Torsen differential, on the other hand, multiplies the force that can still be delivered on the low-traction wheel by the ratio of the TBR to the wheel with greater traction or slower rotation.
▶ RESULTS OF THE OIL ANALYSIS
▶ BROOKFIELD -40°C
ASTM D 2983
The Torsen differential will begin to work faster, the oil will circulate more quickly and there is no wear caused by a low temperature start. With regard to the parameters for dynamic viscosity at minus 40 °C
- The lower the dynamic viscosity, the better.
RAVENOL AWD-TOR Fluid delivers 34,89% higher performance than the original oil VW G055145A2.
▶ MEASUREMENT OF WEAR PROTECTION AND PRESSURE LOAD PROPERTIES
FBT = FOUR BALL TESTER
WEIGHT 40 KG
CYCLE TIME 1 HOUR
The RAVENOL four-ball tester according to DIN 51350 is used to determine the values for lubricants which are exposed to surface pressure in a system with parts in relative motion to one another. In addition to the shear stability at high pressures, the wear protection behaviour when the pressure build-up is low can also be determined.
The four-ball tester is a common test procedure in the lubricant industry and it is used for product development and quality control.
The four-ball system consists of three fixed balls of the same size (stationary balls) and one rotating ball (load ball). The lubricant being tested is then poured over the stationary balls until they are completely covered. Using a lever device and a staged regulation of the test weights, different loads are generated and the corresponding characteristic values for abrasion, friction and welding are determined.
- The higher the welding force or the lower the wear values of an oil or grease, the better its wear protection when subjected to pressure load.
RAVENOL AWD-TOR fluid delivers 10,87 % higher performance than the original oil VW G055145A2.
▶ VKA EP WELD-LOAD
DIN EN ISO 20623:2018-04
Four ball test – Extreme pressure
This process is particularly used for lubricants that have to withstand high loads and pressures. Contained EP additives enable high pressures in the mixed friction area. The four-ball value is given in N (Newtons).
RAVENOL AWD-TOR fluid withstands 5% more strain than the original oil VW G055145A2.
▶ SHEAR STABILITY, KRL, LOSS OF VISCOSITY
TAPERED ROLLER BEARING TEST 20-HOUR
KRL test to determine viscosity changes in multigrade oils, usually gear or axle. The viscosity improver in these oils can be severely sheared during operation. As a result, the oil becomes thinner over time. The KRL test uses the four-ball device to measure the change in viscosity associated with the decrease in viscosity index (VI) improver. Instead of the four balls, this test is carried out with a tapered roller bearing with about 40 ml of oil. With the splash lubrication method, the oil is sheared with the rotating tapered roller bearing at a temperature of 60 ° C, a constant load of 5,000 N and usually over a period of 20 hours. The resulting relative viscosity drop at 100 ° C is given as a percentage.
- Less better
RAVENOL AWD-TOR Fluid is 26,47 % better than the original oil.
▶ COPPER STRIP TEST: EFFECT OF CORROSION ON COPPER
ASTM D130: 2012
Test duration 3 hr
Temperature: 121 °C
The procedure determines the corrosive effects of lubricating oils and greases on copper. Corrosion to metal is based on factors including but not limited to active sulphur compounds in the oil. The level of corrosion at the end of the experiment is ascertained by comparing the copper strip with a colour scale. The result is placed in one of four main categories (1-4) and, within these, two to five sub-categories (a-e).
- Lighter better