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ACTION
EFFECT
Off-power Action
Off-power the Active Diff works the same way as standard front
differential, so adjustment is made by using different viscosities
of silicone oil to get the desired off power steering. The softer
the oil, the more off-power steering but the car will be more
aggressive.
On-power Action
The main advantage of the Active Diff is readily apparent when on-
power. The diff becomes harder and more locked when throttle is
applied, giving a lot of forward traction and stability to the car.
GEAR
WHEN TO USE
Standard / Larger
Gear
Standard / larger gear recommended for tracks with good grip
Optional / Smaller
Gear
Optional / smaller gear recommended for slippery tracks.
Increases stability but introduces slight amount of on-power
understeer
GEARING
2.2
Proper gearing is one of the most essential
tuning options required to maximize the
performance potential of your car.
PRIMARY DRIVE RATIO
2.2.1
Most modern off-road cars & truggies (including the XRAY XB808) feature a single-speed
transmission, so gearing is adjusted by changing the pinion gear (on the clutchbell)
and the spur gear (on the central differential)… also known as the “primary drive ratio
(PDR).” It is very important to establish the best gear ratio for each track environment,
engine/chassis setup and driving style.
•
Smaller pinion / larger spur
= high gearing (long/tall) = faster acceleration but
lower top speed
•
Larger pinion / smaller spur
= low gearing (short) = slower acceleration but higher
top speed
GEAR MESH ADJUSTMENT
2.2.2
DETAIL
Proper gear mesh between the center diff spur gear and the clutchbell pinion gear is vitally
important to obtain optimal drivetrain operation, smoothness, and effi ciency. Improper
gear mesh can result in a binding drivetrain, overstressed clutch/diff components, and
chipped or broken gear teeth.
WHEELS, TIRES, AND INSERTS
2.3
Wheels, tires and inserts — and how they are set up — have a tremendous impact on
the overall performance and drivability of the car.
Before you start making changes on the chassis setup, take a movement to observe a
few of the fastest cars at the track and what type of tires and inserts they are running.
Changing to the best tire combination for the particular track may have a huge impact on
handling, performance and signifi cantly reduce your lap times.
