07/01/2019
Should You Upgrade Your Audi A4 Quattro Suspension?
Modifications to the Audi A4 Quattro are immensely popular among car enthusiasts. While chasing more horsepower is a common goal, it's crucial to remember that a balanced approach to performance is key. Before you even think about adding more power, ensuring your vehicle can handle that power effectively is paramount. A well-sorted suspension system is the foundation of any high-performance vehicle, allowing you to harness increased power and enjoy a more engaging driving experience. If you're looking to unlock your Audi A4 Quattro's true potential, focusing on suspension upgrades should be a top priority. This article will delve into the essential aspects of upgrading your Quattro's suspension, covering everything from the basics of coilovers to the benefits of enhanced braking systems.
The Importance of a Superior Suspension Set Up
As the saying goes, "You should always make the suspension faster than the engine." This adage holds significant weight in the automotive world. Being able to turn and stop effectively is fundamentally more important than simply being able to accelerate quickly. A well-tuned suspension system on your Audi A4 Quattro can dramatically improve your car's handling, allowing you to out-corner the competition and achieve better lap times, especially in spirited driving or track day scenarios. If your Quattro came from the factory with softer, comfort-oriented suspension, it will likely feel less responsive and exhibit more body roll during aggressive manoeuvres. Upgrading to a performance suspension setup, such as a set of high-quality coilovers, is one of the most impactful modifications you can make. Even if your car's suspension isn't factory-spec, old and worn-out components will severely compromise handling and should be replaced, particularly if you engage in any form of enthusiastic driving where precise control is essential.
Understanding Coilover Basics
Coilovers are a popular and effective solution for upgrading your Audi A4 Quattro's suspension. They are essentially integrated shock absorber and spring units that allow for precise adjustment of both ride height and damping characteristics. By lowering your vehicle's centre of gravity, coilovers significantly reduce body roll during cornering, leading to improved stability and control. Furthermore, a stiffer chassis, a common benefit of performance coilovers, translates directly into a more connected feel between the driver and the road. Beyond the performance gains, many enthusiasts also appreciate the aesthetic improvement coilovers provide, allowing for a sportier, more aggressive stance. This transformation isn't just about looks; it's a critical step in allowing your Audi A4 Quattro to truly become a performance machine, ensuring that any power modifications are translated into tangible improvements in acceleration and handling.
Key Features to Consider When Buying Coilovers:
The market for coilovers is vast, with numerous brands and types available, which can make the selection process seem daunting. To help you make an informed decision, here are four key aspects to scrutinize when choosing coilovers for your Audi A4 Quattro:
- Spring Rates: Springs are the backbone of any suspension system. They dictate how your vehicle absorbs bumps, manages weight transfer during acceleration, braking, and cornering, and ultimately control the amount of body roll. Higher spring rates require more force to compress, which, in turn, reduces suspension travel and limits body movement. By minimizing excessive body movement, your car's handling becomes more predictable, and the cornering load is distributed more evenly across all four tyres, leading to enhanced grip. Most aftermarket coilovers feature significantly stiffer springs than their OEM counterparts, providing a more direct connection to the road and improving driver feedback, especially during spirited driving.
Comparison of Spring Rates:
Spring Rate (kg/mm) Typical Application Effect on Handling 1-4 OEM / Comfort Focused Softer ride, more body roll 5-8 Enthusiast Street / Light Track Reduced body roll, improved responsiveness 9+ Dedicated Track / Race Minimal body roll, maximum grip, requires stiffer damping - Spring and Valving Adjustability: One of the primary reasons enthusiasts opt for coilovers is the ability to adjust the ride height, allowing for a lower centre of gravity and reduced body roll. However, high-quality coilovers offer more than just ride height adjustability. The ability to adjust spring preload and damping is equally crucial for fine-tuning your vehicle's handling characteristics and achieving the perfect stance for your specific application. Furthermore, the option to replace springs with different rates is a valuable feature, especially for those who plan to use their Audi A4 Quattro for track days. Track cars typically require much higher spring rates to maximise grip and minimise body roll. It's important to note that when you change spring rates, you must also match them with appropriate damping settings to avoid a harsh or bouncy ride, which can ultimately be detrimental to handling performance.
- Top Mount: The top mount is the component that secures the top of the coilover assembly to the vehicle's chassis. Between the mount and the strut assembly, you'll typically find either rubber bushings or pillowball (spherical) bearings. Original Equipment Manufacturers (OEM) commonly use rubber bushings because they offer excellent NVH (Noise, Vibration, and Harshness) isolation, contributing to a more comfortable ride. However, this compliance also means that rubber bushings can deflect significantly under cornering loads, leading to a less precise suspension feel and potentially compromising handling precision. While stiffer rubber bushings can improve longevity and reduce deflection compared to softer OEM bushings, pillowball mounts offer the ultimate in precision. These are metallic spherical joints that, unlike rubber bushings, do not deflect under cornering forces. This lack of deflection translates into a far more direct and communicative connection between the suspension and the steering wheel, providing a more precise feel for what the car is doing.
- Monotube Design: Inside most dampers, you'll encounter one of two primary designs: monotube or twin-tube. A twin-tube damper features an inner tube that houses the piston shaft, valves, and damping fluid, while an outer tube contains damping fluid and pressurised nitrogen gas. When the suspension compresses, the piston forces fluid from the inner tube into the outer tube via its valves. As the piston retracts, fluid is drawn back into the inner tube. Most OEM suspension systems utilise the twin-tube design as it generally allows for a longer suspension stroke and contributes to a more comfortable ride quality. In contrast, a monotube damper consolidates the gas and shock absorber fluid within a single tube, with a floating piston separating the two. This design forces the damper piston to push the fluid through precisely calibrated valves within the piston itself. This arrangement allows the gas to be compressed more effectively, resulting in quicker and more consistent damping response. Monotube dampers can also be mounted in any orientation, unlike many twin-tube designs. Compared to twin-tube dampers, monotube designs generally hold more fluid, offer superior heat dissipation, and provide a more responsive damping action. For drivers seeking the best possible performance on both the street and the track, the monotube design represents a significant upgrade over the traditional twin-tube setup.
Considering Air Suspension
If your primary focus isn't dedicated track use, but rather a blend of street performance and aesthetic appeal, air suspension presents an excellent alternative to traditional coilovers. While often associated with show cars, many modern air suspension kits are robust enough to handle light track use. The debate between coilovers and air suspension can be passionate, but the unparalleled adjustability of ride height offered by air suspension makes it a compelling option for many Audi A4 Quattro owners. The ability to instantly raise or lower your vehicle provides a unique level of versatility, allowing you to navigate speed bumps with ease or achieve a slammed stance for car shows.
The Role of Sway Bars
When modifying your Audi A4 Quattro, don't overlook the importance of sway bars (also known as anti-roll bars). Most factory cars are tuned with an inherent understeer bias, which is designed to make them safer and more predictable at their limits. For instance, a stock Mitsubishi EVO 8, an all-wheel-drive turbocharged performance car, typically comes with a front sway bar that is stiffer than the rear. While the EVO might require other upgrades, modifying the rear sway bar is often one of the first and most effective steps to counteract understeer and achieve a more neutral handling balance. On a project EVO 8, upgrading the rear bar to a slightly thicker diameter was found to nearly eliminate the car's natural understeer tendencies. The size and stiffness of a sway bar can make a profound difference in how your car handles. It's important to remember that lowering your vehicle can alter your suspension geometry, potentially preloading the sway bars incorrectly and leading to unpredictable handling or even component damage. To avoid this, it's advisable to use adjustable endlinks to properly set the preload on your sway bars after lowering your car.
Don't Forget About Brakes!
While increasing your Audi A4 Quattro's speed is exhilarating, the ability to slow down effectively is equally, if not more, critical. Whether you're building a dedicated race car or a capable street machine, your braking system's performance and endurance will significantly impact your driving experience. Big brake kits typically consist of larger calipers, which house more pistons to apply greater and more even pressure to larger brake pads. These larger pads make more contact with the brake rotor, requiring less pedal travel to achieve a complete stop. This not only improves stopping power but also helps to mitigate brake fade. Brake fade is a dangerous phenomenon caused by the buildup of heat during prolonged braking, leading to a reduction in braking performance. Larger calipers also aid in dissipating heat away from the braking system, further reducing the likelihood of fade. The ability to brake efficiently, safely, and with a touch of style makes a Big Brake Kit a vital component for any performance-oriented Audi A4 Quattro build.
In Summary
The possibilities for modifying your Audi A4 Quattro are virtually limitless. However, by focusing on these core suspension and braking upgrades, you'll be well on your way to transforming your vehicle into a more capable and engaging machine. Upgrading your suspension is not just about aesthetics; it's about unlocking the true performance potential of your car, ensuring it can handle the power you throw at it and provide an exhilarating driving experience. For further insights into performance upgrades, including exhaust systems and ECU tuning, we encourage you to explore our comprehensive blog.
Frequently Asked Questions:
Q1: Will upgrading my suspension make my Audi A4 Quattro uncomfortable?
While performance suspension setups are generally stiffer than OEM components, the level of comfort can vary greatly depending on the specific product and its adjustability. Many coilovers offer adjustable damping, allowing you to fine-tune the ride for a balance between performance and comfort. Air suspension also provides excellent comfort and adjustability.
Q2: Do I need to upgrade my brakes if I upgrade my suspension?
It's not strictly necessary, but it's highly recommended. As your suspension improves, you'll likely be able to carry more speed through corners, meaning you'll need a braking system that can reliably slow you down. Upgrading brakes is a crucial part of a balanced performance build.
Q3: Can I install coilovers myself?
While some experienced DIYers can tackle coilover installation, it's a complex job that requires specific tools and knowledge of suspension geometry. Improper installation can lead to poor handling and safety issues. If you're not confident, it's best to have them installed by a professional mechanic.
Q4: What is the difference between coilovers and lowering springs?
Lowering springs are a direct replacement for your factory springs and are designed to lower the car. They work with your existing shock absorbers. Coilovers, on the other hand, are complete integrated units of spring and shock absorber, offering adjustability in ride height and damping, providing a more comprehensive performance upgrade.
Q5: How does AWD affect suspension upgrades on my Audi A4 Quattro?
The Quattro all-wheel-drive system is a significant advantage for handling. When upgrading your suspension, you'll want components that complement the AWD system, ensuring balanced grip and stability. Coilovers and proper alignment are key to maximising the benefits of your Quattro system.
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