Jeep grand cherokee 2017 User Manual page 170

• Tire pressure:
– 40 psi (276 kpa) hot, recommend
32 psi (221 kpa) front, 30 psi (207 kpa)
rear cold
NOTE:
It is recommended that you target 40 psi
(276 kpa) Hot Tire Pressure at the conclusion
of each track session. Starting at 32 psi
(221 kpa) Front & 30 psi (207 kpa) Rear
Cold and adjusting based on ambient & track
conditions is recommended. Tire pressure
can be monitored via the instrument cluster
display and can assist with adjustments.
Track burnishing your brakes:
To avoid "green lining fade" during track use,
the brake pads and rotors must have a ther-
mal burnish for factory installed components
or when new brake friction components are
installed:
1. Use one track session to burnish brakes
by driving at 75% speed. Brake at ap-
proximately 0.60-0.80g max without ABS
intervention.
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2. Lap the track in this manner until you
start smelling the brakes. Continue for
another ½ lap at speed, then do a two lap
cool down with minimal brake applies.
Make sure the brakes are not smoking. If
they are, do another cool down lap.
3. Do not continue for more than 1 full
burnishing lap after you start smelling the
brakes. Do not get them smoking heavily.
This will get them too hot and affect their
life negatively in future track use.
4. Allow vehicle to sit and cool in the pad-
dock for at least 30 min. If an infrared
thermal gun is available, allow rotors to
cool to 200°F (93.3°C) before going back
out.
5. There should be a thin, ash layer when
inspecting the pads installed in the cali-
per. Having the ash layer go more than
half the thickness of the pad material
indicates too aggressive of a burnish.
6. Sometimes, a second burnish session is
required. If the pads start smelling in the
next track session, reduce speed and
braking decel to burnish targets and fol-
low step 2-4.
7. New pads installed on old rotors still need
to be burnished. New rotors installed with
old pads should be burnished at the track
or street driven for 300 city miles to
develop an adequate lining transfer layer
on the rotor surface prior to track use.
8. Rotors that pulsate during track use
should be replaced. Resurfacing of the
rotors is not recommended, as it removes
mass from the rotor, reducing its thermal
capacity. Resurfacing also thins the rotor
cheek, making it less robust and increas-
ing the likelihood of pulsation in further
track use.