Damper Components
Components
1. Spherical Bearing Mount
2. Rebound Adjuster
3. Upper Spring Seat
4. Primary Spring
5. Helper Spring
6. Lower Spring Seat
7. Compression Adjuster
8. Threaded Main Body
9. Reservoir
10. Spanner Wrench
11. Spring Seat Hex Wrench
• Your Viper ACR is delivered with the suspension adjusted for optimal street comfort. Below are the adjustment capabilities:
Compression Damping: 14 settings front and rear
Rebound Damping: 19 settings front and rear
Ride Height: +/- 1
14in. (32 mm)
• Any adjustments to the suspension settings should be made in small increments.
CAUTION!
The use of improper tools may severely damage your suspension. The tools included
with your Viper ACR are the only tools that should be used for adjusting the ride
height.
Ride Height Adjustment
• Your ACR is delivered from the factory at a ride height that provides a good balance for
drivability on the street. The adjustable suspension allows for ride height adjustment.
As with all of the suspension adjus tments, caution should be used when changing the
ride height.
• Before any adjustments are made to your ride height, clean threaded area with soapy
water to be sure it is free and clear of debris.
CAUTION!
Only the factory ride heights should be used while operating the vehicle on the street.
Low ride heights can cause damage to the vehicle.
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Adjusting the ride height:
• Raise and support the vehicle. Both left andright side wheels should be lifted off the
ground to allow adjustment of the spring
seats without damage. Never make ride
height adjustments with the suspension
loaded. The helper spring should never be
fully compressed while adjusting ride
heights.
• Remove the wheel and tire assembly.
• Loosen the set screw on the lower spring seat (approx 1 turn).
• To lower the ride height, use the spanner wrench and rotate the lower spring seat counter-clockwise (as viewed fr om below the damper). Use the set screw as a
reference to return to street height.
• To raise the ride height, first turn the seat in the counter-clockwise direction and ensure the threads are clear of debris. Use the spanner wrench and reverse the
direction.
• Tighten the set screw to 22 in-lbs (2.5 N·m). DO NOT over tighten this screw.
• The ride height adjustment sensitivity is as follows: • Front: One turn = 0.104 in. (2.6 mm) height change at frame
• Rear: One turn = 0.134 in. (3.4 mm) height change at frame
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PERFORMANCE/ACR
Compression Adjustment
• The compression adjustment (also calledbump) varies the damping of the upward
travel of the wheel relative to the vehicle.
• The compression adjuster is located on the remote canister fixed to the damper body
and has 14 damping positions. Depending
on vehicle ride height, the car may need to
be raised to gain access to the compression
adjuster. To adjust the compression
damping, turn the finge r knob: clockwise
stiffens; counterclockwise softens when
viewed from the top surface of the finger
knob.
• All settings are referenced from the full stiff (position “0”). The “0” position on
compression is achieved by turning the
finger knob clockwise until you cannot turn
it any further.
CAUTION!
To avoid damage to your dampers DO NOT force the finger knob when it stops turning.
Also, NEVER use any tools to adjust the finger knob.
• From the “0” position, turning the adjuster cou nterclockwise will soften the damping.
Count off the clicks and record your setting. Every “click” is a new damping position
(i.e. two clicks softer from the full stiff position is position “2”).
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Rebound Adjustment
• The rebound adjustment (also called droop)varies the damping of the downward travel
of the wheel relative to the vehicle.
• The rebound adjuster is located on top of the piston rod and has 19 damping
positions. Depending on vehicle ride height,
the car may need to be raised to gain access
to the rebound adjuster. To adjust the
rebound damping, turn the upper finger
knob: clockwise stiffens; counterclockwise
softens when viewed from above.
•
All settings are referenced from the full stiff
(position “0”). The “0” position on rebound
is achieved by turning the finger knob
clockwise until you cannot turn it any further.
CAUTION!
To avoid damage to your dampers DO NOT force the finger knob when it stops turning.
Also, NEVER use any tools to adjust the finger knob.
• From the “0” position, turning the adjuster cou nterclockwise will soften the damping.
Every “click” is a new damping position (i.e. two clicks softer from the full stiff
position is position “2”).
Street Set Up
• Best Comfort is achieved at the following damper settings and should always be used when driving on the street:
Front Compression Position “13”
Front Rebound Position “18”
Rear Compression Position “13”
Rear Rebound Position “17”
Ride Height Adjustment
• The factory ride height of your ACR is approximately: Front: 514in. (132 mm)
Rear: 6 in. (153 mm)
• Measured from the bottom of frame rail to ground at the axle centerline with no passengers, a full tank of fuel and tire pressures set to 29 psi.
• A low ride height setting may not be optimal at all tracks. It will generally be more acceptable to run a lower ride height at a track with smoother surfaces, fewer abrupt
elevation changes and fewer bumps. The optimum set up for your vehicle also varies
with track, driver and ambient conditions. Below is a recommended starting point for
two typical track configurations.
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PERFORMANCE/ACR
Smooth track set up:
Front: 4 in. (102 mm)
Rear: 5 3/8 in. (136 mm)
Rough track set up:
Front: 4.375 in. (111 mm)
Rear: 5 1/2 in. (140 mm)
• The rake of the car (or front to rear ride height difference) may also be changed with your ACR suspension. Changing the rake may be beneficial at some tracks. Use
caution when changing the rake angle.
CAUTION!
Depending on your set up, driving styl e, and track condition, some tire to wheel liner
contact may occur. To avoid excessive wheel liner wear, adjust your ride height
accordingly.
Notes on Tuning
Damper Adjustment
• Adjusting from the street settings should be done only at track events. A
recommended starting position for the tracks is:
Front Compression Position “6”
Front Rebound Position “6”
Rear Compression Position “5”
Rear Rebound Position “5”
• Always start from a known position (full stiff).
• Adjust in small increments (1-2 clicks).
• Record your adjustment settings at all four wheels.
• Continually monitor and record your tire pressures.
• Remember that suspension damping, ride heights, rake angle and aerodynamic
balance all work as a system. As you make changes to one end of the vehicle, it will
affect the balance of the car.
Maintenance and Inspection
• Regularly inspect the splitter rub strips and out board knock-in nut. Regularly inspect
all attachments of the aerodynamic components (see Aerodynamics section).
• Track use will greatly increase wear rates and service intervals on your Viper ACR. Repeated track use requires more frequent fluid changes.
NOTE: Although your vehicle is shipped with 0W40, it is recommended to use Mobil-1
15W50 synthetic motor oil at the track.
• Always run a cool down lap at the end of a track outing. For track outings lasting longer than 25 minutes, an external rear axle cooler is recommended.
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OPENING THE HOOD
• Reach into the lower right grille opening and pull the primary hood latch forward.
• Raise the front of the hood slightly and push the safety catch handle to the right. Thesafety catch handle is located under the front edge of the hood.
• Assist props will ra ise the hood to a normal usage p osition. If greater access is
required, the hood may be pushed up at the front, raising the hood beyond the initial
opening height.
• To close, lower the hood until it is open ap proximately 6 in (15 cm) and then drop it.
This should secure both latches.
WARNING!
Be sure the hood is fully latched before driving your vehicle. If the hood is not fully
latched, it could open when the vehicle is in motion and block your vision. Failure to
follow this warning could result in serious injury or death.
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MAINTAINING YOUR VEHICLE