Circle Track Suspension Tech & Tips

TUNING TIPS

The following template was designed to assist you in breaking down the corner into three main areas. First, establish what handling characteristic your car possesses, then, using the template, determine in what area of the corner you are experiencing the problem. Follow the recommended adjustments in order to optimize your vehicle’s cornering potential.

0 ̊ thru 60 ̊ Corner
Entry Problem: Loose at turn entry

• Increase compression on front or right front
• Decrease rebound in left rear

Problem: Tight at turn entry

• Decrease compression on front or right front
• Increase rebound in left rear

60 ̊ thru 120 ̊ Mid Corner
At most tracks this part of the corner is where the car has taken a set. Your braking is already done, your steering angle is constant and you are getting ready to pick up the throttle. Typically, your car’s handling characteristics are influenced by vehicle geometry and roll centers at this part of the track and less likely affected by shock valving.

120 ̊ thru 180 ̊ Corner Exit
Problem: Loose at turn exit

• Decrease rebound in right front
• Decrease compression in left rear

Problem: Tight at turn exit

• Increase rebound on right front
• Increase compression on rear or right rear only

Always start tuning by concentrating on the problem that happens first in the turn. For example, if you are loose exiting the turn, it is possible that it is happening because you are tight entering the turn. The extra steering input from trying to “drive through the push” could cause the car to seem loose at mid-corner and at exit. Once the “push” entering is fixed, the loose condition exiting the corner could go away.

QUICK TIPS

Suspension Clearance
Always check the clearance on all suspension arms, shocks and springs through the entire range of travel. The extra clearance through the entire range of travel could mean the difference in being competitive after contact with another car or a DNF due to a bent suspension component.

Spacing
In the event that you need to space the shock away from the mounting bracket to gain clearance, then use a small diameter spacer. If you space the shock with a nut or washers, they could hit the shock bearing or loop as it goes through suspension travel.

Bearing Maintenance
The shock bearings that do not have a nylon race should have penetrating oil applied and then worked by hand for regular maintenance. Wipe the excess oil from the bearing when you are finished so that it does not collect dirt.

Binding
Check the entire suspension without springs and shocks for binding or tight rod ends or bushings. If the suspension is tight, the chassis will see it as additional spring rate. Binding and then freeing-up in the typical suspension travel range is an even worse condition. It will be adding spring rate at times and not adding it at others, thereby making the chassis inconsistent.

Stud Mount
Always check for binding when you mount a stock-type stud mount shock. The mount opposite the stud mount should be installed first and tightened. If the stud mount is contacting the side of the mounting hole, then you will need to elongate the hole. The stud should not be hitting any part of the upper mounting hole. This would cause it to bind in the mounting.

Dented Bodies
QA1 twin tube shocks are designed to function even if the body is dented, unless the damage is severe enough to reach the inner tube. Any dented shock should be checked for internal damage. In the “old days”, a sealed shock could not be easily checked for damage, but our design allows you to be certain that the shock is operating at 100% efficiency. First, visually check the inner tube for any signs of damage. Next, work the piston rod into the inner tube to check for any tight spots and/or check the inside diameter with a dial gauge.

General Maintenance
Some QA1 shocks are designed to be repairable, rebuildable and revalveable by the racer, while others are designed to be serviced by QA1 authorized service centers. While QA1 shocks are designed to be run on dirt or asphalt, it is still important to keep dirt and debris out of the shock absorber as much as possible. To do so, wipe down the piston rod regularly and, if needed, cover the shock with tubing (see frequently asked questions). QA1 shocks are also designed to be and will need to be checked and replaced or repaired as needed. Please contact QA1 for parts prices.

Limit Straps
The modern dirt track car relies on large amounts of extension travel on the left side of the car. Using the shock as a travel limiter can be extremely hard on the internal components of the shock. Adding a simple limit strap can significantly reduce the wear and tear on your shock absorbers.

Measuring Ride Height
Compressed and extended mounting lengths are measured from the center of loops and/or shock shaft/stud shoulders. If the measurements are taken from mounting surface to mounting surface, subtract 5/8” for each shaft/stud end. The preferred measurement in most cases is taken with the car sitting on the ground as ready to go. If initially setting up the chassis, simulate the approximate ride height (stance) before measuring.