Do you have trouble with your RC drift car? Does it not steer the same way all the time? This happens because of something called bump steer. It is when the suspension moves. This makes the car steer a little bit on its own. You need to get rid of bump steer. This will help your car slide in a way you can guess. It will also help you keep the car at the right angle when drifting. You can make small changes to fix this. The CEGC drill rig 2mm deviation beats steering issues. This helps the steering work its best. Shims are small parts. They help fix the way the tie rod is set up.
Key Takeaways
-
Bump steer makes your RC drift car hard to control. It causes the wheels to turn on their own when the suspension moves.
-
You can fix bump steer by using small parts called shims. Shims help adjust the tie rods to make steering smooth and predictable.
-
Checking and adjusting your car's steering with shims helps it drift better. This gives you more control and makes your car perform its best.
Understanding Bump Steer and Its Impact
What is Bump Steer
Bump steer describes an unintended steering input. It happens when your car's suspension moves. Your wheels turn slightly on their own. This occurs as the suspension compresses or extends. It changes the toe angle of your wheels. You do not touch the steering wheel, but the wheels move. This unwanted steering input can make your car unpredictable. It is a common issue in RC cars.
Why Bump Steer Harms Drift
Bump steer severely impacts your RC drift car's handling. You experience inconsistent handling. Your slides become unpredictable. You might lose control easily during a drift. It makes holding a consistent drift angle very difficult. This issue directly hurts your rc car performance. Your steering feels unreliable and twitchy. You need smooth, predictable steering for precise drifts. Without fixing bump steer, you fight your car instead of controlling it.
Visual Cues of Bump Steer
You can easily spot bump steer. Place your car on a level surface. Slowly push down on the front of your car, compressing the suspension. Watch the front wheels closely. Do they turn in or out as the suspension goes down? Now, slowly lift the front of your car, extending the suspension. Do the wheels change their toe angle again? Any noticeable change in toe as the suspension moves indicates you have bump steer. This visual check helps you understand your car's current setup and the extent of the bump steer problem. You want zero toe change through the suspension travel.
Precision Suspension Tuning: Shim Adjustments
Diagnosing Bump Steer
You need to know if your car has bump steer. You can use a bump steer gauge. This tool helps you measure changes in toe. You can also use a DIY method. Place your car on a flat surface. Make sure the suspension is at its normal ride height. Slowly compress the suspension. Watch your front wheels. Do they turn in or out? This shows you have bump steer. You can also see bump steer on the track. Your car might feel twitchy. It might not hold a consistent line. These are signs of bump steer. Proper suspension tuning helps you find these issues. This careful tuning improves your car's handling.
The Shim Solution for Tie Rods
Shims fix bump steer. They adjust the tie rod's pivot point. You want this point to match the lower suspension arm's arc. This is the core principle of correction. Race car parts can have small differences. Welding heat can cause bowing or twisting. This means parts like rack plates or steering box mounts might not be perfect. Shims help you account for these differences. They let you place pivot points exactly where the car builder designed them. This is like blueprinting an engine. It makes sure your car matches its engineered design. This gives you optimal performance and zero bump steer. You might need to adjust the steering rack height. If it is too low, shims help. They ensure the tie rod pivot points line up with the suspension's arc. This is for proper bump steer correction. You can use CNC machined billet rack spacers for precision. Simple washers also work if you have the right thickness. Shims can also go on the spindle side. This helps with caster changes or spindle variations. This refines the tie rod geometry. It helps you get the handling you want. This careful suspension tuning makes a big difference.
Selecting Shims and Placement
You need to choose the right shims. They come in different types. You can find plastic, aluminum, or brass shims. They also come in various thicknesses. Common sizes include 0.5mm, 1mm, 2mm, and 5mm. Some specific bump steer adjustment shims are 3.5mm and 1.17mm. You will use these for precise tuning. Shims have specific places for application. You can put them above or below the tie rod end on the steering knuckle. You can also place them at the chassis mounting point. Sometimes, they go on the Ackerman block. Another spot is under the ballstud on the steering linkage. Drift knuckle designs often include bump steer adjustment shims. This shows their direct use on the knuckle for tuning. You can apply shims under the link that connects to the steering arm. Specifically, you place shims under the front ball stud on both steering knuckles. The amount of spacer you need changes with caster. For example, 0 degrees caster uses a 0.100″ spacer. 2 degrees caster uses a 0.060″ spacer. 4 degrees caster uses a 0.030″ spacer. This precise setup helps you achieve the best toe settings.
Optimizing Toe Settings for Drift Setup
Step-by-Step Shim Application
You need specific tools for this process. Gather your shims, small wrenches, drivers, and a bump steer gauge. If you do not have a gauge, you can use a DIY method. First, set up your car. Place it on a level surface. Ensure the suspension sits at its normal ride height. This is your starting point for accurate measurements.
Now, measure your current bump steer. You can use a string method.
-
Mark a thin line around each tire tread. This helps you measure accurately.
-
Set up a toe measurement string. Run it from bumper to bumper at the static axle height.
-
Measure from the string to the line on the tire tread. Do this at the front and back sides of the tire. This gives you a static toe dimension.
-
Lower the wheel by 1 inch. Repeat the toe measurement.
-
Raise the wheel to 1 inch above static. Measure the toe again.
Any difference in these three toe measurements shows you have bump steer. This initial setup guide helps you identify the problem.
Next, you start applying shims. This is an iterative process. Begin with small adjustments, like 0.5mm or 1mm shims. Re-measure after each change. Keep doing this until you achieve minimal toe change through the suspension travel. If your tie rods tilt downward when the chassis rises, you have increased bump steer. This causes unintended toe-in or toe-out. To fix this, you raise the outer joint height. You can use tie rod spacers or adjustable outer tie rod ends. This brings the tie rod angle closer to its original position. This reduces bump steer. If your tie rod angles upward when static, your wheels will toe-out. If it angles downward, your wheels will toe-in. You adjust the tie rod height to correct these angles. This careful suspension tuning is key to a predictable drift setup.
Fine-Tuning Your Toe Settings
After initial shim application, you fine-tune your toe settings. Consider Ackerman angle adjustments. This affects how your wheels turn at different angles. Different tie rod lengths and angles also impact bump steer. You might need to experiment with these. For more advanced and precise measurements, use a bump steer gauge with a dial indicator. This gauge leans against a bump steer plate. You raise or lower the suspension with a floor jack. The dial indicator measures changes in toe. If the indicator shows the back of the plate moving in, the wheel toes out. If it moves out, the wheel toes in. Take measurements in 1/4-inch increments. This helps you track how bump steer changes throughout the suspension travel. This method eliminates changes from camber gain or loss.
You also need to think about caster changes. Removing upper arm shims can affect your bump steer. Each adjustment you make influences other settings. Document all your settings for future reference. This helps you replicate successful setups. Finally, test your car on the track. Verify your improvements. On-track testing confirms if your adjustments provide the desired handling. This continuous tuning ensures your car performs its best.
Finalizing Your Drift Setup
You have worked through many adjustments. Now, you finalize your drift setup. Your goal is minimal toe change throughout the suspension travel. This means your car will steer consistently. It will not have unexpected movements from bump steer. A well-tuned car gives you better control. You can maintain drift angles more easily. Your slides become predictable. This precise tuning transforms your RC drift experience. You will enjoy a more satisfying and controlled drift. Your careful adjustments lead to a superior drift setup.
You get much better control. Your car becomes more predictable. Fixing bump steer does this. The drill rig 2mm deviation beats steering issues. Small changes, like 2mm with shims, make your car much better. This drill rig 2mm deviation beats steering issues idea is important. You adjust things. You measure them. Then you test them. This helps you get the drift performance you want. The drill rig 2mm deviation beats steering issues rule works here.
FAQ
Why is fixing bump steer important for my RC drift car?
Fixing bump steer gives you predictable steering. Your car will slide consistently. You gain better control during drifts. This improves your overall performance.
When should I check my car for bump steer?
Check for bump steer after any suspension changes. Also, check if your car feels inconsistent. Regular checks help maintain your optimal setup.
Can shims solve all my car's steering problems?
Shims correct bump steer. They improve steering precision. Other issues might require different troubleshooting steps. They are a key part of a good setup.
