Pan Car Setup and Troubleshooting Problems can come up in the midst of competition. Either the car is not handling properly on the track or there are problems with equipment. Troubleshooting problems should be performed in a methodical manner. Work patiently and always make a single change at a time and observe the result(s) of that change. Also take good notes of the changes and the resulting effects. Over time, you will develop enough experience and knowledge to readily recognise the root cause of a problem and correct it. Description of Problem Possible Cause of Problem Car is oversteering Rear tire compound is too hard. Front tire compound is too soft. Front tire diameter is too large. Front suspension springs are too soft. Rear pod movement is too tight. Grease on the rear friction damper plates is too thick. Spring tension on the coil damper or rear shock absorber is too high. Spring tension on the friction damper plates is too high. Viscosity of oil in rear shock absorber is too high. Ball differential setting is too tight. Ball differential setting is too loose. Ball differential is damaged. Thrust bearing in the ball differential is not slipping properly. Corrective Measure Change to softer rear tire compound. Change to harder front tire compound. Reduce the front tire diameter. Remember to re-adjust the ride height. Change to stiffer front springs. Loosen the rear pod (T-bar to main chassis) screws to increase rear pod travel without excessive side to side movement. For even better rear pod movement and control, you can switch to an optional ball mount suspension set. Apply thinner grease on the rear friction damper plates to increase movement of the rear pod. For even smoother response, you can switch to Teflon friction damper plates. Decrease the spring tension by removing spacers or switch to a softer spring to transfer the driving load to the rear end. Also, lightly grease the coil damper shaft for smoother movement. Switch to softer springs to decrease the amount of compression applied to the friction damper plates. For smoother response and easier adjustments, switch to using an adjustable friction damper post assembly. Change to a lower viscosity oil in rear shock absorber. Re-adjust the ball differential to the proper setting. Adjust the rear right axle nut to tighten the ball differential setting and decrease slippage on acceleration. Replace damaged ball differential parts. Replace thrust bearing assembly with a properly oiled one piece thrust bearing for smoother cornering response.
Car is understeering Rear center of gravity is too high. Rear wing down force is too low. Front wing down force is too high. Lower the rear end center of gravity using an adjustable ride height gear case to raise the rear axle ride height. Change to a rear wing with three wings (instead of two for increased wing surface area) and/or a higher wing angle. For improved rear wing down force, a rear diffuser set will improve the airflow over the rear wing for higher down force. Change to a smaller front wing with a lower angle. Toe-out angle of front tires is too large. Toe-in front wheels and increase toe-in angle as Front tires experience "edge bite" on hard cornering. Steering servo is too fast in response. Front tire compound is too hard. Front tire diameter is too small. Rear tire compound is too soft. Front suspension springs are too stiff. Chassis flexes too much. Rear pod movement is too loose. Grease on the rear friction damper plates is too thin. Spring tension on the coil spring damper or rear shock absorber is too low. Viscosity of oil in rear shock absorber is too low. Ball differential setting is too tight. Front end ride height is higher than rear end ride height. Weight distribution is lighter at the front end. Round the shoulder of the front tires. Trim steering response if possible. Change to softer front tire compound. Change the front tires to a larger diameter tire set or reduce the diameter of the rear tires. Change to harder rear tire compound. Change to softer front springs. Increase chassis stiffness by changing from the stock chassis plate to a hard carbon-type chassis plate or add the optional FRP upper chassis set (Tamiya Part No. 53186). Tighten the rear pod (T-bar to main chassis) screws to limit rear pod travel. Apply thicker grease on the rear friction damper plates to slow movement of the rear pod. Increase the spring tension with additional spacers to transfer the driving load to the front end. Change to a higher viscosity oil in rear shock absorber. Adjust the rear right axle nut to loosen the ball differential setting and slightly increase slippage on acceleration. Increase rear end ride height using an adjustable ride height gear case to increase front end steering. Reduce weight of rear end and/or move weight distribution forward. You can also switch to a different chassis that allows repositioning of the batteries for better weight distribution.
Car does not turn in either direction evenly. Car steering is unstable on straight-aways Front wing down force is low. Toe-in angle of front wheels is too large. Steering servo is too slow in response. Chassis is tweaked. Servo horn neutral position is not set properly. Steering trim for neutral position of the radio transmitter is not properly set. Change to a larger front wing with a higher angle. Toe-out front wheels and decrease toein angle as A slight toe-out may be necessary. Change to a faster steering servo. Adjust suspension settings to remove chassis tweak. Set the servo horn in neutral position with equal steering arm length. Adjust steering trim with radio transmitter steering in neutral position. whichever needs adjustment. Servo is not firmly secured to the Servo saver is worn or loose. Bent steering Uneven tire wear. Uneven bearing wear. Secure the servo to the chassis with glass tape and servo tape. Tighten the servo saver to the servo or replace servo saver Replace and/or true tries to even diameters on each side, both front and rear as Replace worn bearings. whichever needs adjustment. Tires are not glued properly. Front tires are in toe-out condition. Inadequate toe-in angle. Wheel is not firmly secured with lock nut. Servo is not firmly secured to the Glue the tires securely. Adjust front tires for toe-in condition. Increase toe-in angle. Tighten the lock nut to hold the wheel in position. Secure the servo to the chassis with
Uneven tire wear Servo saver is worn or loose. Steering trim for neutral position of the radio transmitter is not properly set. Steering blocks are creating oversensitive steering response. Uneven tire wear. Uneven bearing wear. Bent steering Too much play in front end Uneven front spring tension or length. T-bar mounting screws are loose. Countersunk T-bar mounting holes are damaged. Radio interference is causing the steering servo to glitch. Uneven front spring tension or length. Unbalanced wheels. glass tape and servo tape. Tighten the servo saver to the servo or replace servo saver Adjust steering trim with radio transmitter steering in neutral position. Change to offset steering blocks. Replace and/or true tires to even diameters on each side, both front and rear as Replace worn bearings. Replace excessively worn components as Either replace the shorter spring or place a greater preload on it with spacers. Tighten T-bar mounting screws as Replace the T-bar and mounting screws. Identify and eliminate source of radio interference (also see "Radio transmitter is not working." Either replace the shorter spring or place a greater preload on it with spacers. Balance the wheels using lead tape used for balancing golf clubs.
whichever needs adjustment. Car ride is very bumpy Bent steering Rear axle intermittently seizes. Unbalanced wheels. Wheel is not firmly secured with lock nut. Tires are rubbing against other Both front and rear tire compounds are too hard. Spring on damper unit is too stiff. Damper fluid is too viscous. Friction damper plate grease is too viscous. Too much play in front end Clean and lubricate rear axle assembly and replace bearings as Balance the wheels using lead tape used for balancing golf clubs. Tighten the lock nut to hold the wheel in position. Increase tire clearance for free movement. Change to softer tire compounds for the front and rear. Replace damper spring with a softer spring. Replace damper fluid with a lower viscosity fluid. Replace friction damper plate grease with a thinner grease. Replace excessively worn components as Too much play in rear end Replace excessively worn components as Worn spur or pinion gear teeth. Worn motor armature. Replace worn gear and properly set gear mesh. Replace any worn armature components as