How to Corner-Balance Coilover Suspension for Optimal Handling and Performance

Understanding Corner Balancing: The Foundation of Optimal Handling

Corner balancing, sometimes referred to as “corner weighting,” “weight jacking,” or “scaling,” involves adjusting the spring perches of a car to get a balanced diagonal weight on the tires. This process is one of the most critical yet frequently overlooked steps when installing coilover suspension. All too often, car owners skip the essential step of corner balancing their vehicle but wonder why the handling got worse after installing a new set of coilover suspension.

The effectiveness of the tires at any point is largely determined by the weight balance of the car. Think of your suspension like a four-legged table. If one leg is shorter than the others, the table wobbles and doesn’t sit flat. Picture a wobbly chair or table, a minor difference in leg height results in some legs doing all of the support work while others sit idly above the ground. On any car, weight that presses down on a corner improves the grip of that tire. In turn, if one end of the car is lighter than the other, those tires on the light end will have less traction.

When you install coilovers without proper corner balancing, you’re essentially creating an unstable platform. If the front left and right rear corners are heavier than the other corners, you’ll experience to a lesser effect the teetering that an unbalanced chair or table does. If the front left and right rear are sitting heavy, you might find that the car feels more responsive turning right than it does left. But once you’ve started turning right, the car is more prone to oversteer because of the lighter weight left rear corner. The car could also feel sluggish when starting a left turn, but more controllable after the turn is initiated.

What Is Cross Weight and Why Does It Matter?

Cross-weight percentage compares the diagonal weight totals to the car’s total weight. To calculate cross-weight percentage, add the RF weight to the LR weight and divide the sum by the total weight of the car. This diagonal weight distribution is the key metric you’re trying to optimize during corner balancing.

Cross-weight is also called wedge: If the percentage is over 50 percent, the car has wedge; if below 50 percent, the car has reverse wedge. More wedge means that the car will likely understeer more in a left turn. The advantage to wedge is that the left rear tire carries more load, so the car drives off the turns better. For most street and road racing applications, you want to target as close to 50% cross weight as possible for balanced handling in both left and right turns.

50% Cross Weight: Neutral handling balance where the vehicle has equal grip in left and right turns. Greater than 50% (Positive Wedge): Promotes oversteer, where the rear of the vehicle tends to step out during cornering. Less than 50% (Negative Wedge): Promotes understeer, where the vehicle tends to push toward the outside of the turn. Understanding this relationship helps you diagnose handling issues and make informed adjustments.

Corner balancing and static weight distribution are different things. Corner balancing can only adjust weight on the diagonal corners. You cannot change the overall front-to-rear or left-to-right weight distribution through corner balancing alone—that requires physically moving components or adding ballast. What corner balancing does is optimize the diagonal weight distribution within your existing weight distribution constraints.

Essential Equipment for Corner Balancing

Wheel Scales: Your Most Important Tool

Corner weight scales, also known as racing scales or balance scales, are a type of automotive equipment used to measure the weight distribution across a vehicle’s four corners. They consist of four individual scales, one for each wheel of the vehicle. By placing each wheel on a scale, you can get a precise measurement of how much weight is being borne by each corner of the car.

You need accurate automotive-grade scales—not bathroom scales. Each weigh pad has multiple load sensors delivering highly precise weighing results with an accuracy of 0.1%. Additionally, weight pads exhibit a deflection of 0,53 mm or less at 500 kg. Modern digital scales often include wireless connectivity and built-in calculators that automatically compute cross weight, left/right percentages, and front/rear distribution.

Popular brands include Intercomp, Longacre, and LABA7. Intercomp’s RFX® Wireless Racing Scales are the choice of championship-caliber racers around the world. The system provides reliable and secure communication between scale pads and a wireless indicator or a PC using our field-proven, encrypted wireless technology. Utilizing this robust, field-proven technology simplifies the corner balancing process for racecars and other racing vehicles. The cable-free system allows the user to walk around the vehicle to check or adjust suspension settings at each corner and see the results of those changes, instantly.

Additional Tools You’ll Need

• Coilover wrenches or spanner keys: These specialized tools fit the locking collars on your coilovers for height and preload adjustments
• Floor jack and jack stands: Essential for safely lifting the vehicle to make adjustments
• Laser level or bubble level: When setting up your scales, you will want to make sure all four pads are perfectly level with each other. Starting off on a relatively level surface helps. Using a laser level with targets is the most accurate way to do this, but a long bubble level works too.
• Measuring tape: For recording ride height measurements at consistent reference points
• Notebook or spreadsheet: To track measurements and adjustments throughout the process

Some enthusiasts also invest in hub stands, which allow you to make suspension adjustments without removing wheels each time. We have been considering Hubstands because of the ease in setting the weights. You can easily get to the suspension without having to unbolt the wheel every time you need to make a change, then bolt it back on to see if you changed it enough.

Preparing Your Vehicle for Corner Balancing

Setting Initial Ride Height

It’s important to note that you should also set your coilovers to your preferred ride height and align the car before starting a corner balance. The adjustments of corner balancing will usually be close enough that a few millimeters of adjustment won’t alter your alignment enough to be noticeable. Start with the ride height you actually plan to use, whether for street driving or track use.

For this reason it’s best to set the ride height where you want it, align the car and then corner balance it last. Usually, you’ll be close enough that a few mm won’t affect the alignment enough to measure. This sequence—ride height, alignment, then corner balance—minimizes the need for repeated adjustments.

Understanding Spring Preload

In simple words, preload is nothing more than the pressure that’s applied to the spring before the load of your car compresses it. When adjusting preload, you are simply adding (or removing) weight to (or from) a fully extended shock for optimum suspension travel. It’s important to understand that with linear-rate springs (which most coilovers use), spring height’s been adjusted roughly one inch, introducing more preload (top), but since it’s a linear-rate spring, it won’t affect handling or ride quality—just ride height.

Spring preload should be set before the coilovers go on the car, then position the spring perches to roughly where you want the car ride height to sit, set your wheel alignments, and then finally corner balance the car. Most manufacturers recommend 3-5mm of preload. Some manufacturers still recommend a very small amount of preload to be used just to stop the springs sliding on the pans and making noise; BC Racing for example suggests 5mm of spring preload.

Critical Preparation Steps

Before placing your car on scales, complete these essential preparation steps:

1. Set tire pressures: Set your tire pressures as they would be HOT on the track. Use your target operating pressures, not cold pressures.
2. Add driver weight: Static weight distribution is the weight resting on each tire contact patch with the car at rest, exactly the way it will be raced. This means the driver should be in the car, all fluids topped up, and the fuel load should be such that the car makes your minimum weight rule at the designated time-usually after a race. Use ballast bags or sandbags positioned in the driver’s seat to simulate your weight.
3. Fuel level: Make sure all the fluids are topped off and the fuel level is where you want it. Fuel levels will slightly change your corner balance depending on where your fuel tank is. You can strategize whether you want the car perfectly balanced in the beginning, middle, or end of a race.
4. Disconnect sway bars: Sway bars are disconnected (if there are adjustable endlinks), otherwise, leave the bars connected. Lastly, you also need to make sure the sway bars don’t have preload in them-that can also skew the results. If your sway bar endlinks are adjustable, it’s an easy fix. If not, as long as the car is at the same ride height left to right, you should be OK.
5. Wheels straight: The front wheels must also be straight because the caster of the front wheels alters the corner balance as the wheels turn.

The Corner Balancing Process: Step-by-Step

Step 1: Level Your Scales

Place your four scales on a flat surface. When setting up your scales, you will want to make sure all four pads are perfectly level with each other. Starting off on a relatively level surface helps. Using a laser level with targets is the most accurate way to do this, but a long bubble level works too. If you don’t have adjustable levels for your scales, you can use pieces of sheet metal or something similar to shim the scales. This step is absolutely critical—uneven scales will give you false readings and make proper corner balancing impossible.

Step 2: Position the Vehicle

When performing a corner balance, the vehicle is driven onto an alignment rack or a known perfectly flat surface and the weight scales are placed under each wheel/tire. Drive the car onto the scales carefully, ensuring each wheel is centered on its respective scale pad. You will want to make sure the car is fully settled when taking your weight measurements, otherwise you will get inconsistent readings. There are a couple of ways to do this: Drive directly onto the scales with ramps to avoid unloading the suspension.

Rolling the car back and fourth many times is required without long roll-off ramps to ensure there’s no preload in the system. Bounce the car by hand and roll it on and off the scales to remove suspension binding. This settling process ensures you’re measuring the true static weight distribution without any binding in the suspension components.

Step 3: Record Initial Measurements

With the car settled on the scales, record the weight at each corner:

• LF (Left Front)
• RF (Right Front)
• LR (Left Rear)
• RR (Right Rear)

With the car on the scales make note of the current mass distribution. It will show individual mass at each wheel but it will more importantly show the percentage difference side to side, front to rear and something called the cross weight percentage. The cross weight percentage is khown on the screen below as “CR” and is the difference between the diagonal mass sums of the car (LR+RF and RR+LF).

Calculate your cross weight percentage: (RF + LR) ÷ Total Weight × 100. Your goal is to get this number as close to 50% as possible for neutral handling. A perfect balance is very rarely possible, but if you can get to within .01-.1% of a perfect cross weight, that is ideal.

Step 4: Make Adjustments

Adding load to a corner is done by raising the ride height of that corner. On a car, this is typically done via coilovers, and can be accomplished by adding preload to the springs. It can also be accomplished using coilovers that are adjustable via shock length. The key principle to remember: raising a corner increases the corner weight on that corner and its diagonal opposite, and decreases the weight on the other two corners. We aren’t changing the mass of the car; that must remain constant.

Here’s how adjustments affect corner weights:

• RAISING any one corner will INCREASE the weight on that corner and slightly affect all other corners.
• That load (weight) you are adding to the lengthened corners is being alleviated from the opposite diagonal corners. As an example, raising (adding weight to) the Front Right corner will take weight off the Front Left and Rear Right.
• It is important to note that if we increase the weight supported by one tire, say the LR, we also increase the weight supported by the diagonal corner of the car, in this case, the RF tire. As we make that change, the opposite change takes place at the other diagonal because those tires (the LF and RR) experience a decrease in the amount of weight they will support.

Make small adjustments at a time. The stiffer your spring rates, the more sensitive it will be to changes. Start with just one or two turns of the adjustment collar. Important point – always adjust two wheels (usually diagonally opposite) a little – and we’re talking perhaps a 20 degree turn on a ‘HiLo’ adjuster here – rather than one a lot. This will avoid tantrums when getting one corner right, but throwing two others off, and doing weird things to your ride heights!

Step 5: Settle and Remeasure

After each adjustment, you must settle the suspension again. For consistency, make sure the suspension is fully settled each time you record the weights. This is probably the most important and tedious part of the job. Even with slip plates, we still like to jounce the suspension a few times just to make sure. Every time you make a change, rock the car back and forth to help the suspension settle back into place. Also roll the car back and forth a few times to help further. Skipping this step will change the results and send you chasing problems endlessly.

Record your new corner weights and recalculate the cross weight percentage. Compare the results to your previous measurements to understand how much effect your adjustment had. It’s also a good practice to note how much each change affected the weights, in order to give you a reference to more quickly make changes in the future.

Step 6: Iterate Until Balanced

The process is to measure wheel weights and plug them into the Corner Balance Equation. In the real world the equation will never be in perfect balance. If the imbalance is outside acceptable range you will adjust one or more spring heights, re-measure the wheel weights and do another trial of the Corner Balance Equation. Repeat until the imbalance is brought to an acceptably low value.

Corner balancing without hub-stands is a tedious process – so you want to learn the patterns and try to make good guesses to only need a couple of adjustments! With experience, you’ll develop an intuition for how much adjustment is needed. How much you should adjust the perches depends on springs rates, but you can start off with one turn at a time to gauge how much of a difference it makes. Even for someone who does corner weighting all the time, it took multiple adjustments to get this car perfect.

Post-Balancing Adjustments and Fine-Tuning

Reconnecting Sway Bars

Once the corner balance is done, you will want to reinstall your sway bar end links. Ideally, you will have adjustable end links so they can be reconnected without any preload. Your suspension will need to be fully loaded and settled when you reconnect them. With all the ride heights set and the target mass distributions achieved the coilovers can now be locked off and the adjustable drop links can be adjusted in length so that the anti-roll bar re-connects with the suspension with ease meaning that no strain is being put in the roll bar when the car is sat stationary.

Alignment Check

Your alignment may have changed from the spring perch adjustments during the corner balance process. With the corner weighting now complete, it is likely that the alignment will have been affected considerably. Even though you aligned the car before corner balancing, the small ride height changes made during the process can alter camber, caster, and toe settings.

It’s best to have the car aligned before scaling. Changes to things like caster can jack weight and will affect corner weights. If possible, it’s a good idea to touch up alignment settings after corner balancing as well. A post-balance alignment check ensures your suspension geometry is optimized for the new corner weight distribution.

Sway Bar Tuning

With your corner weights balanced, you can now fine-tune handling characteristics using sway bar adjustments. Sway bars control body roll and affect the balance between understeer and oversteer. If your car understeers (pushes wide in corners), stiffen the rear sway bar or soften the front. If it oversteers (rear end steps out), do the opposite.

There are other related items that come into play when you’re getting serious about car setup, like fine tuning the damping characteristics and making sway bar adjustments. Make small changes and test drive between adjustments. Keep detailed notes of what works and what doesn’t for your specific vehicle and driving style.

How Corner Balancing Improves Performance

Enhanced Grip and Traction

By evenly distributing the vehicle’s weight across all four corners, you can achieve improved grip, reduced tire wear, and enhanced predictability, allowing you to push your vehicle to its limits with confidence. When each tire carries its fair share of the vehicle’s weight, all four contact patches work at optimal efficiency.

Improved Handling: By ensuring that your vehicle’s weight is evenly distributed, you can improve its handling and stability, especially during high-speed turns. Better Traction: Proper weight distribution can also enhance traction, reducing the likelihood of wheel spin and improving acceleration and braking performance. Optimized Suspension: Corner weight scales allow you to fine-tune your suspension settings, ensuring that each wheel is carrying its fair share of the load.

Predictable Handling Characteristics

A properly corner balanced car will handle evenly in left and right turns. When a car has a proper corner balance performed, the car will feel more “balanced” and/or neutral. Turning, braking, as well as acceleration can all be improved after a corner balance procedure. The car responds consistently regardless of which direction you’re turning, giving you confidence to push harder.

Moving from an unbalanced setup to a properly corner balanced setup is one of those things that most people can’t appreciate until they’ve experienced it themselves. Suspension, however, is too often ignored but can change your car’s handling characteristics from a sloppy mess to a vehicle that darts into corners on demand and with confidence.

Improved Braking Performance

Proper corner balancing affects more than just cornering. When weight distribution is optimized, braking performance becomes more consistent and predictable. The car stops in a straight line without pulling to one side, and brake bias is more evenly distributed across all four corners. This reduces the likelihood of premature brake fade and improves overall stopping distances.

Reduced Tire Wear

Uneven corner weights lead to uneven tire wear patterns. When one corner carries more weight than it should, that tire wears faster and may develop irregular wear patterns like cupping or feathering. Improper corner weights can make the most accurate suspension alignment worthless. Unequal cross weights can destroy a road racing car’s handling and sap driver confidence. Proper corner balancing helps all four tires wear evenly, extending their lifespan and maintaining consistent grip throughout their service life.

Common Mistakes and How to Avoid Them

Skipping the Settling Process

The most common mistake is failing to properly settle the suspension between measurements. Note that a car with a lot of friction or binding in the suspension components will not deliver repeatable corner weights. The friction will resist all suspension movement preventing the corner weights from measuring true (also creates erratic handling). Fix any friction and binding before you corner balance. Always bounce the car and roll it back and forth several times before taking readings.

Making Large Adjustments

Resist the temptation to make big changes all at once. Small, incremental adjustments allow you to understand how your specific car responds and prevent overshooting your target. One or two turns of the adjustment collar at a time is usually sufficient. With stiffer springs, even smaller adjustments may be necessary.

Forgetting About Suspension Geometry

It’s also important to note that actual weight distribution in the vehicle will always be the most important aspect of a vehicle’s balance – the act of corner balancing is meant to optimize your setup. Corner balancing cannot fix fundamental weight distribution problems. If your car has a heavy engine offset to one side or the driver sits far from the centerline, corner balancing helps but cannot completely eliminate the imbalance.

Additionally, extreme ride height changes during corner balancing can negatively affect suspension geometry. If you are unable to achieve the correct mass balance by adjusting the ride heights within reason (within 30mm of damper length of each other) then it might be a better solution to add ballast mass in the vehicle. Ballast masses are plates that you can bolt into the car at different locations which will make that point heavier and will change the mass distribution of the car. The only downside to this is that the overall mass of the car will increase, which will ultimately reduce the top speed and acceleration slightly.

Not Recording Data

When corner balancing, always write down your weight and height next to each other as shown below, along with your changes to ride height to help you keep track of the changes you’ve made and the results for each step. Create a spreadsheet or notebook system to track every measurement and adjustment. This data becomes invaluable for future setup changes and helps you understand patterns in how your car responds.

Advanced Considerations for Different Applications

Street vs. Track Setup

Street Cars: 50-52% cross weight, balanced left-right distribution, and front-rear distribution as designed by the manufacturer. For street use, aim for neutral balance with cross weight as close to 50% as possible. This provides predictable handling in all conditions and even tire wear.

For track use, you might deviate slightly from perfect 50% cross weight depending on the specific track layout and your driving style. Circuit Racing: Near 50% cross weight for balanced left and right turn performance. However, Oval Track Racing: Typically 52-58% cross weight to help the car turn left more effectively. Circle track racing requires specialized setups that favor one direction.

Adjusting for Different Vehicles

Different chassis designs respond differently to corner balancing. Mid-engine cars like the Porsche Cayman require special attention to front-to-rear balance due to their unique weight distribution. Front-engine, rear-drive cars typically have more weight on the front axle, which affects how you approach corner balancing.

Front-Wheel Drive Race Cars: 52-54% cross weight, slightly front-biased weight distribution (55-58% front). Rear-Wheel Drive Race Cars: 49-52% cross weight, rear-biased weight distribution for better traction (48-50% front). These guidelines provide starting points, but always test and adjust based on actual handling characteristics.

Spring Rate Considerations

Spring rates significantly affect how your car responds to corner balancing adjustments. Stiffer springs require smaller adjustments to achieve the same weight change compared to softer springs. When you change spring rates, you must re-corner balance the car, as the new springs will distribute weight differently even if ride height appears the same.

Remember that changes in stagger, tire pressures and springs will change the ride height and alter the cross-weight percentage. Any time you change springs, tires, or tire pressures, plan to recheck your corner weights and make adjustments as needed.

Long-Term Maintenance and Monitoring

When to Recheck Corner Weights

Corner balancing isn’t a one-time procedure. You should recheck corner weights whenever you:

• Change spring rates or springs
• Adjust ride height significantly
• Replace suspension components
• Notice handling changes or uneven tire wear
• Add or remove weight from the vehicle (audio equipment, roll cage, etc.)
• At the beginning of each racing season

How often should I check cross weight? Before every major race or after making suspension changes. For serious track use, checking corner weights before each event ensures you’re starting with optimal setup.

Monitoring Tire Wear Patterns

Tire wear patterns tell you a lot about your corner balance. If one tire wears significantly faster than its diagonal opposite, your cross weight may have drifted. Even wear across all four tires indicates good corner balance. Uneven wear on one side of a tire suggests alignment issues rather than corner weight problems, though the two are related.

Check tire tread depth regularly at multiple points across each tire. Keep records of tire wear rates to identify trends. If you notice one corner wearing faster, it’s time to put the car back on scales and verify your corner weights haven’t changed.

Documenting Your Setup

Always record the cross-weights and ride heights for reference at the race track in case changes are needed. Create a comprehensive setup sheet for your vehicle that includes:

• Corner weights at each position
• Cross weight percentage
• Ride height measurements at consistent reference points
• Spring perch positions (count threads showing)
• Alignment specifications
• Tire pressures (cold and hot)
• Sway bar settings
• Damper settings
• Date and conditions when measured

This documentation allows you to return to a known good setup if experiments don’t work out, and helps you understand what changes produce what results over time.

Testing and Validation

On-Track Evaluation

The real test of corner balancing comes when you drive the car. We treat each vehicle setup as a custom-tailored suit, paying close attention to your feedback, goals, and experience. Understanding how your car behaves on the track — whether it tends to oversteer (rear wheels losing grip), understeer (front wheels losing grip), or exhibits other handling characteristics — is vital to our customization process. Your inputs help us decipher your vehicle’s current behavior, allowing us to tailor adjustments that align with your preferences and driving style. For instance, some drivers might prefer a neutral handling car that’s stable through corners, while others might prefer a more responsive car that leans towards oversteering.

Pay attention to how the car feels in both left and right turns. A properly corner-balanced car should feel equally responsive and predictable in both directions. Note any differences in how the car enters, holds, and exits corners. Does it feel planted and confident, or does one end feel lighter than the other?

Making Track-Based Adjustments

Make small changes at the track, and make only one change at a time. If you need to make adjustments at the track, change only one variable and test again. This methodical approach helps you understand cause and effect rather than chasing multiple variables simultaneously.

If the car understeers or oversteers in only one direction, check the cross-weight percentage. Directional handling imbalance often indicates cross weight issues. If the car understeers in left turns but oversteers in right turns (or vice versa), your cross weight percentage is likely off target.

Data Logging and Analysis

For serious track use, data logging systems provide objective feedback about how setup changes affect performance. Lap times, sector times, and telemetry data showing speed through specific corners help you quantify improvements. Compare data before and after corner balancing to see the real-world impact.

Tire temperature measurements across the tread surface also provide valuable feedback. Ideally, temperatures should be relatively even across the tire, indicating good contact patch and proper camber. Significant temperature differences between diagonal corners may indicate corner weight imbalance.

Professional vs. DIY Corner Balancing

When to Seek Professional Help

Corner balancing can be a complex and time-consuming process, requiring specialized equipment and expertise. It’s highly recommended to seek professional assistance from a reputable performance shop or suspension specialist to ensure accurate and precise results. Professional shops have experience with various chassis types and can often achieve optimal results more quickly than a first-time DIY attempt.

Consider professional corner balancing if you:

• Don’t have access to quality scales
• Are preparing for serious competition
• Have a complex or unusual chassis
• Want to learn the process from experienced professionals
• Need alignment services at the same time

DIY Corner Balancing Benefits

That said, corner balancing is absolutely achievable for dedicated enthusiasts. The process is actually not too difficult, but it does require the proper tools and know-how to do it right. The truth is – its very simple to do, either through purchase of a basic gauge for a modest sum or self-manufacture for very little outlay. Your patience and time is the biggest input. As a task, setting corner weights is easier than caster, camber, and tracking setting.

DIY corner balancing offers several advantages:

• Deeper understanding of your vehicle’s setup
• Ability to make adjustments at the track
• Cost savings over repeated professional services
• Flexibility to experiment with different setups
• Satisfaction of optimizing your own vehicle

If you choose the DIY route, invest in quality scales and take your time learning the process. Start with your street car before attempting to corner balance a dedicated race car. Join online forums and communities where experienced enthusiasts share knowledge and troubleshooting tips.

Conclusion: The Foundation of Handling Performance

Corner balancing represents one of the most cost-effective performance improvements you can make to a vehicle with coilover suspension. This is probably one of the most cost-effective methods of tuning the handling of your car. While it requires patience, attention to detail, and proper equipment, the results speak for themselves in improved handling, tire wear, and driver confidence.

One of the most important aspects of racing is having a good handling balance. Setting static weight distribution and adjusting cross-weight percentage is one way to assure good handling. Whether you’re building a dedicated track car, improving your weekend autocross competitor, or simply want your street car to handle its best, proper corner balancing unlocks the full potential of your coilover suspension investment.

Remember that corner balancing is part of a comprehensive suspension setup process. When setting up a new set of coilovers, there are actually a few elements to pay mind to: alignment, spring preload, ride height, and corner weights. There are other related items that come into play when you’re getting serious about car setup, like fine tuning the damping characteristics and making sway bar adjustments. But the former list comprises the essential items when first setting up your car. Spring preload should be set before the coilovers go on the car, then position the spring perches to roughly where you want the car ride height to sit, set your wheel alignments, and then finally corner balance the car.

Take the time to do it right, document your results, and test thoroughly. The difference between a properly corner-balanced car and one that’s simply been lowered is dramatic. Your tires, your lap times, and your confidence behind the wheel will all benefit from this essential but often overlooked aspect of suspension tuning.

For more information on suspension setup and performance tuning, consult resources from organizations like the Sports Car Club of America, National Auto Sport Association, and suspension manufacturers’ technical documentation. These authoritative sources provide detailed specifications and best practices for various vehicle platforms and racing applications.