Rocket 4 Manual

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4. Ride Height and Car Weight
The ride height is the distance between the track and the bottom of the chassis. For most loose dirt tracks the normal
ride height should be 18mm in the rear and 17mm in the front. A little more ride height in the rear is usually good
because the rear of the car will squat under acceleration. Ride height is adjusted with the various shock mounting holes
provided on the car and fine-tuned using the threaded collars on the springs. Ride height can be lowered for extremely
smooth high bite tracks, and can be raised if the chassis is bottoming out.
Weight in the form of brass or lead can be added to the car to make the car easier to drive on low bite or bumpy tracks.
The added weight helps keep the tires pushed into the track. However adding weight will directly affect ride height by
lowering the chassis, which is NOT what you want in this situation. So when adding weight, make sure you re-adjust the
ride height.
5. Camber Links and Roll Centers
The hinge pin and camber link positions described in the kit instructions provide the standard roll center locations for this
car. Both front and rear camber links can be shortened by using optional holes included. Shortening the camber links
will cause the car to react quicker at the expense of stability. Front and rear can be adjusted independently to achieve
the proper chassis balance for a given track condition.
Lowering the inner camber link location will raise the roll center and cause the chassis to roll less in corners. Less roll is
generally better for conditions where traction is very high. Also be aware that lowering and/or shortening the camber
links will increase camber gain as the suspension compresses.
6. Cross-weight
Cross-weight which is sometimes referred to as “wedge” can help tighten or loosen the car. Since oval racing consists
only of left turns, there is less need to keep the weight of the car equally balanced between the left and right side tires.
Increasing the spring tension on the left rear and right front shocks will add weight to those corners and make the car
tighter. Doing the opposite will make it looser. Be careful not to go too far, excessive cross-weight can upset the ride
height and not allow the suspension to work properly. A set of scales is required to measure cross-weight and should be
measured on a level surface with the car as “ready to race” as possible.
7. Rear steer
Rear steer is created with the use of the adjustable rear arms. Because the car spends a great amount of time turning
left, it is more efficient to have the rear tires help with the steering. The amount of rear steer needed largely depends on
the track. Tighter turns require more rear steer. The most common setting is 4 degrees in on the left rear and 1 degree
in on the right rear. To help the car turn more, try 6 degrees in on the left and 1 degree out on the right. To make the
car drive straighter try 3 degrees in on the left rear and 2 degrees in on the right rear. This is also a very easy
adjustment to make before a race to quickly adapt to a changing track surface.
8. Spoiler adjustment
Adjusting the spoiler angle on a late model body or adding a vertical wicker bill to the top of the spoiler can have a
dramatic effect on how the car drives. More angle or adding a wicker bill will plant the rear of the car and help keep it
from spinning out. Less angle usually works better on high grip tracks where aerodynamic downforce is less needed.
Experiment to determine how much angle feels good at a particular track.
9. Droop
Droop is the distance the tires can drop before they lose contact with the track when the chassis is lifted. Droop can be
limited by the use the different shock mounting holes or with spacers inside the shocks. Limiting the droop in the front
suspension will give the car more steering and limiting rear droop can provide more rear side bite. However a car with
little or no droop will not handle the bumps in the track as well and can cause a car to be erratic. More droop works
better on a low grip track and less droop works better on a high grip track.
10. Other adjustments
The adjustments above account for most of the changes needed to dial the car into a given track. Other adjustments are
included in the car such as camber, Ackermann, wheelbase, front track, shock angle, etc. Even more option parts are
available such as sway bars, optional caster blocks and front suspension mounts.