27/12/2014
Keeping Your Porsche 928 Stopping Power Optimal
The Porsche 928, a true icon of German engineering, is renowned for its performance and distinctive styling. However, like any high-performance vehicle, maintaining its braking system is paramount for both safety and driving enjoyment. If you're a proud owner of a 928, you'll know that while these cars offer exhilarating acceleration, ensuring they can stop just as effectively is crucial. This guide delves into sourcing essential brake parts for your classic 928 and explores popular modifications to enhance your car's stopping capabilities.
Where to Find Porsche 928 Brake Parts
When it comes to sourcing parts for a classic like the Porsche 928, finding a specialist supplier is key. For owners in the UK and beyond, Heritage Parts Centre stands out as a comprehensive resource. They offer a dedicated selection of brake components specifically for the Porsche 928, covering everything from essential replacements to performance enhancements. Their inventory includes:
- Brake Discs (Rotors): Crucial for dissipating heat and providing the friction surface for your brake pads.
- Backing Plates: These protect surrounding components from brake dust and heat.
- Replacement Brake Pads: Available in various compounds to suit different driving styles.
- Calipers: The hydraulic cylinders that clamp the brake pads onto the discs.
Heritage Parts Centre positions itself as a one-stop shop for Porsche 928 parts and accessories, continually expanding its range of spares for classic Porsche models. Whether you're performing routine maintenance or embarking on a restoration, they are a valuable point of contact.
Understanding Porsche 928 Brake Rotors: Cost and Considerations
The cost of a Porsche 928 brake rotor can vary significantly depending on the material, manufacturer, and whether it's a standard replacement or a performance upgrade. While a precise figure for every rotor is difficult to pinpoint without specific part numbers and suppliers, general estimates can be made. For a pair of high-quality replacement rotors, you might expect to pay in the region of £800 - £1000, as suggested by some DIY cost estimates. It's always advisable to get a direct quote from your chosen supplier.
Key considerations for brake rotors include:
- Material: Cast iron is standard, but performance rotors may use different alloys for better heat management.
- Design: Slotted or drilled rotors can help dissipate heat and gas, but can also wear pads faster.
- Weight: Lighter rotors, often referred to as "floating" rotors, reduce unsprung weight, which can positively impact handling and performance.
Enhancing Your 928's Braking System: Popular Modifications
Porsches are built for speed, and the 928 is no exception. However, many owners find that the stock braking system, while adequate for its era, can be significantly improved to match the car's potent engine and driving dynamics. Enhancing your braking system is not just about performance; it's a critical safety upgrade. The 1979-1995 Porsche 928 can benefit greatly from strategic brake modifications.
1. Calipers and Brake Pads: Increased Stopping Power
Upgrading your calipers and brake pads is one of the most effective ways to boost stopping power. Modern performance calipers, often featuring more pistons, provide greater clamping force and more even pressure distribution onto the brake rotor.
DIY Cost Estimate for Caliper Upgrade:
| Component | Estimated Cost (DIY) |
|---|---|
| Front & Rear Caliper Set | ~ $845 |
| Motiv Power Bleeder | ~ $45 |
| Brake Fluid | ~ $30 |
| Total DIY Component Cost | ~ $920 |
Professional Installation: Typically requires 2-4 hours of labour, excluding parts. The skill level for this job is moderately difficult, involving the removal and reinstallation of brake components, and crucially, the successful bleeding of the brake system to remove all air.
Benefits of Upgraded Calipers:
- Increased Stopping Power: More pistons mean more force applied to the pads.
- Weight Savings: Performance calipers can be significantly lighter than stock, reducing unsprung mass.
- Wheel Clearance: Larger calipers, such as 4-piston or 6-piston units, can accommodate larger brake rotors and may offer better wheel fitment options. However, be mindful that very large calipers (e.g., 6-piston) can sometimes present clearance issues with certain wheel designs.
Forum-Shared Part Numbers for Reference:
- GTS Big Black Left Front Caliper: 928.351.423.03
- GTS Big Black Right Front Caliper: 928.351.424.03
- S4/GT/GTS Black Left Rear Caliper: 928.352.421.03
- S4/GT/GTS Black Right Rear Caliper: 928.352.422.03
- Hawk Front HPS Pad Set: HB184F.650
- Hawk Rear HPS Pad Set: HB170F.650
Choosing the right brake pads is equally important. High-performance street (HPS) pads offer a good balance of stopping power, responsiveness, and everyday usability.
2. Performance Rotors: Lighter and More Effective
Upgrading your brake rotors can also yield significant improvements. Performance rotors are often designed to be lighter and incorporate features like ventilation slots or cross-drilling to manage heat more effectively.
DIY Cost Estimate for Rotor Upgrade:
| Component | Estimated Cost (DIY) |
|---|---|
| Pair of Performance Rotors | ~ $994 |
| Motiv Power Bleeder | ~ $45 |
| Brake Fluid | ~ $30 |
| Total DIY Component Cost | ~ $1069 |
Professional Installation: Similar to caliper upgrades, expect 2-4 hours of labour. The skill level is moderately difficult, requiring brake system disassembly and proper bleeding. The benefit of lighter, "floating" rotors is a reduction in unsprung weight, which can noticeably improve the car's handling and overall performance feel.
3. Braided Stainless Steel Brake Lines: Improved Pedal Feel
Original rubber brake lines can degrade over time and expand under pressure, leading to a spongy brake pedal feel. Replacing them with braided stainless steel lines offers a more direct and consistent pedal response.
DIY Cost Estimate for Brake Line Upgrade:
| Component | Estimated Cost (DIY) |
|---|---|
| Brake Line Kit | ~ $130 |
| Motiv Power Bleeder | ~ $45 |
| Brake Fluid | ~ $30 |
| Total DIY Component Cost | ~ $205 |
Professional Installation: Typically 1-2 hours of labour. This is generally considered a moderate difficulty task, often easier than removing calipers or rotors, but still requires careful attention to detail, especially during the brake bleeding process.
Why Upgrade Brake Lines?
- Reduced Expansion: Stainless steel braiding prevents the lines from swelling under pressure, providing a firmer pedal.
- Durability: They are more resistant to abrasion and damage, especially crucial if you track your car.
- Improved Feel: Offers a more immediate and precise connection between your foot and the braking system.
These lines are often included in comprehensive brake upgrade kits and can be conveniently replaced when undertaking other brake work, such as changing rotors and calipers.
The Holistic Approach: A Full Brake System Overhaul
While upgrading individual components can provide benefits, for the most significant improvement in your Porsche 928's braking performance and safety, a comprehensive overhaul is highly recommended. This involves upgrading all key elements simultaneously: pads, rotors, calipers, and brake lines.
Pro Tip: Consider the synergy between all components. For instance, larger calipers and rotors might require different spindles for proper fitment. This is particularly true for certain 928 models within specific production years, where VIN-specific spindle conversions may be necessary to accommodate significantly larger brake setups. Researching these compatibility issues thoroughly, perhaps through owner forums and specialist advice, is crucial before purchasing parts.
A complete system upgrade ensures that all parts work harmoniously, delivering the ultimate in stopping power, feel, and reliability for your cherished Porsche 928.
Frequently Asked Questions (FAQ)
Q1: How often should I replace my Porsche 928 brake pads?
A: Brake pad life varies greatly depending on driving style, conditions, and the type of pads used. A visual inspection is the best way to determine wear. As a general guideline, check them every 5,000-10,000 miles, or if you notice any changes in braking performance or hear unusual noises.
Q2: Can I fit larger brake rotors from a different Porsche model to my 928?
A: While it might be technically possible with significant customisation, it's generally not recommended unless you are using a kit specifically designed for the 928 that incorporates components from other models. Direct fitment usually requires matching the bolt pattern, offset, and caliper mounting points precisely. Specialist suppliers often offer kits that achieve this.
Q3: What is "unsprung weight" and why is it important for brakes?
A: Unsprung weight refers to the mass of the vehicle not supported by the suspension, such as wheels, tyres, brakes, and hubs. Reducing unsprung weight allows the suspension to react more quickly to road imperfections, improving ride comfort and crucially, tyre contact with the road. Lighter brake components (rotors, calipers) contribute to this reduction, enhancing both handling and braking effectiveness.
Q4: What is the difference between drilled and slotted rotors?
A: Drilled rotors have holes drilled through them to help dissipate heat and expel gases and dust from the pad surface, which can prevent "brake fade." Slotted rotors have grooves machined into the surface to serve a similar purpose, scraping the pad surface clean and helping to vent gases and dust. Both can improve braking performance, but drilled rotors can sometimes be more prone to cracking under extreme stress, and both can increase pad wear compared to plain rotors.
Q5: Is bleeding the brake system really that difficult?
A: Brake bleeding is a critical step after replacing components like calipers, lines, or even just the fluid. While not overly complex, it requires precision. Air in the brake lines will result in a spongy pedal and significantly reduced braking efficiency. Using a pressure bleeder (like the Motiv Power Bleeder mentioned) simplifies the process considerably compared to traditional two-person methods, making it a more achievable DIY task.
Conclusion
Maintaining and enhancing the braking system of your Porsche 928 is a rewarding investment. Whether you're sourcing standard replacement parts from specialists like Heritage Parts Centre or opting for performance upgrades to unlock your car's full potential, prioritizing your brakes ensures a safer and more exhilarating driving experience. Always consult with reputable suppliers and consider the overall system when making modifications.
If you want to read more articles similar to Porsche 928 Brake Parts & Upgrades, you can visit the Automotive category.