The
original
final
drive
ratios
for
the
Q50
&
Q60's
R190
differential
top
out
at
only
3.133:1
(and
that's
on
the
Red
Sport!),
which
is
fine
for
a
commuter
car
with
the
7-speed
automatic,
but
less
ideal
for
aggressive
competition
use,
or
those
with
transmission/motor
swaps.
We
chose
a
50
tooth
ring
gear
and
a
14
tooth
pinion
which
equates
to
a
3.571:1
ratio
for
the
final
drive.
We
originally
designed
this
for
use
in
our
Q60
Red
Sport
Manual
Conversion,
so
we
chose
a
ratio
that
better
aligns
with
both
the
6-speed
MT's
ratios,
as
well
as
the
power
output
of
the
car,
but
it
can
benefit
factory
automatic
cars,
in
the
right
application.
Switching
to
a
higher
final
drive
ratio
will
increase
the
vehicle's
nominal
RPM
(that
is,
it
will
increase
the
engine
speed
across
the
board,
for
any
given
vehicle
speed),
which
will
also
reduce
the
vehicle's
overall
top
speed.
The
trade-off
is
that
a
higher
final
drive
ratio
will
dramatically
improve
torque
to
the
wheels,
providing
faster
acceleration,
making
it
especially
ideal
for
a
car
that
sees
track
duty
or
competition
use.
The
ring
and
pinion
blanks
are
forged
from
20CrMnTi--
a
chromium,
manganese,
titanium,
and
steel
alloy,
which
is
then
machined
to
final
dimensions,
and
finally
heat-treated
for
uniform
strength.
They
are
designed
to
meet
or
exceed
OEM
quality,
fit,
and
finish.
Professional
Installation
Recommended!
How
to
properly
break-in
a
new
gear
set:
Keep
RPMs
low
and
drive
easy
avoiding
highways
if
possible
for
the
first
20
or
so
miles,
then
stop
and
let
the
differential
and
drivetrain
cool.
Repeat
this
step
four
or
five
more
times,
being
sure
to
allow
the
gears
to
fully
cool
between
each
trip
while
also
avoiding
jerky
acceleration
or
high
RPMs
during
this
period.
After
100
to
150
miles
of
easy
driving,
you
can
start
to
enjoy
the
full
RPM
range,
but
still
be
sure
to
avoid
jerky
accelerations
or
fast
gear
changes
when
possible
for
the
first
500
miles.
At
or
very
soon
after
500
miles,
change
the
gear
oil
in
the
diff
and
check
the
old
fluid
for
metal
shavings
or
other
debris
to
make
sure
there
are
no
abnormal
signs
or
wear.
If
all
is
good,
you're
ready
to
rip!