HISTORY
In conjunction with transmission technology
partner Borg Warner, Nissan developed their own special transmission
fluid for the R35 GTR. It is costs around $100 US per litre (gearbox
holds 10 litres), and needs to be changed often (every 1800 miles if
the vehicle has had track day use). Many owners are finding this to be
overly expensive and has gained the GTR a reputation as being extremely
resource hungry when driven hard or in a competition environment. The
Willall Racing plan was to develop a superior longer lasting lubricant
that would slow gearbox wear to a near standstill and allow more
conventional servicing schedules.
ANALYSIS
Nissan
were correct in advising of regular changes, as samples we took from
our test vehicle at the 1800 mile mark showed that (under Filtergram
testing conditions) fine particles of metal, some as big as 200 microns
existed within the transmission. The problem here is that small bits of
metal, make more bits of metal, and the whole process results in
spiralling and accelerated wear rates. Laboratory testing proved the
factory GR6 fluid to provide very little high temperature lubrication,
allowing metal to metal contact on the gear faces, creating premature
wear conditions, and giving limited 'cushion' to first gear when Launch
Control is activated.
DEVELOPMENT OF WR35TM
Blending and then testing a
suitable high quality gear oil solution required a two pronged attack.
Protecting the gears against wear and metal/metal contact was already
well researched, but making this fluid then work correctly with the
Borg Warner wet clutches and deliver factory feel through the driveline
was the challenge. The perfect balance was achieved after extensive
testing, with WR35TM delivering stock clutch feel, reduced gearbox
noise, and lower operating temperatures. The best news though is that
the wear rate of the gearbox was slowed over 150 times by reducing the
metal/metal contact of the gears.
WR35TM -
Transmission takes 7 litres, with either cooler the 10L is enough. Factory
Service Interval = 3000km when tracking the car, WR35TM can be used for 6000km
of track work (a full year of track days and normal driving) without a change.
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