Let's dive deep into the world of the Nissan Silvia S13 and explore what it takes to handle a whopping 1695 horsepower. Upgrading the gearbox is crucial when you're aiming for such extreme power levels. We'll cover everything from why a stock gearbox won't cut it to the best aftermarket options and what to consider during the installation process. So, buckle up, and let's get started!

Understanding the Limits of the Stock Gearbox

The stock gearbox in a Nissan Silvia S13 is simply not designed to handle the immense power that comes with a 1695hp engine. These gearboxes were originally built for engines producing a fraction of that power, typically around 135-220hp depending on the specific model and engine configuration. When you significantly increase the horsepower, you're also increasing the torque, which puts a tremendous strain on the gearbox components. The gears, shafts, and casings are all susceptible to failure under such extreme conditions.

Common Failure Points:

• Gears: The teeth can shear off, leading to catastrophic failure and rendering the gearbox useless.
• Shafts: These can twist or break under the immense torque, again leading to a complete loss of function.
• Casings: The housing itself can crack or break, especially under repeated stress from high-power applications.
• Synchronizers: These wear out much faster, leading to difficulty in shifting and eventually grinding gears.

Why Upgrading Is Necessary:

If you're planning to push your S13 to 1695hp, upgrading the gearbox isn't just recommended—it's essential. Ignoring this critical upgrade can lead to frequent breakdowns, costly repairs, and potentially dangerous situations on the road or track. Investing in a robust aftermarket gearbox designed for high-horsepower applications will provide the reliability and durability needed to handle the power.

Factors Influencing Gearbox Choice:

• Torque Capacity: Ensure the new gearbox can handle the maximum torque output of your engine.
• Gear Ratios: Choose ratios that suit your specific needs, whether it's for drag racing, drifting, or street driving.
• Material Quality: Look for gearboxes made from high-strength materials like billet steel.
• Cooling: Consider gearboxes with built-in cooling systems to prevent overheating during intense use.

Top Aftermarket Gearbox Options for High-Horsepower S13s

When it comes to upgrading your Nissan Silvia S13 gearbox to handle 1695hp, you have several excellent aftermarket options to choose from. These gearboxes are specifically designed and built to withstand the extreme stresses of high-horsepower applications. Here are some of the top contenders:

1. PPG (Pfitzner Performance Gearboxes)

PPG is renowned for producing high-quality, straight-cut gearsets that are incredibly strong and durable. These gearsets are typically made from billet steel and are designed to handle massive amounts of power. PPG offers complete gearboxes and individual gearsets that can be installed into existing gearbox casings. While they can be noisy due to the straight-cut design, the trade-off is immense strength and reliability.

• Pros: Extremely strong, high torque capacity, proven in racing applications.
• Cons: Noisy operation, higher cost.

2. Quaife Engineering

Quaife Engineering offers a range of sequential gearboxes that are popular among high-performance enthusiasts. These gearboxes provide lightning-fast gear changes, making them ideal for racing and drifting. Quaife gearboxes are known for their precision engineering and high-quality materials, ensuring they can withstand the rigors of high-horsepower applications.

• Pros: Fast gear changes, precise engineering, high-quality materials.
• Cons: Higher cost, requires sequential shifter.

3. Samsonas Motorsport

Samsonas Motorsport is another leading manufacturer of sequential gearboxes. Their gearboxes are designed for extreme performance and are used in various forms of motorsport, including drifting, rally, and circuit racing. Samsonas gearboxes are known for their robustness and ability to handle very high torque levels. They offer various gear ratio options to suit different driving styles and applications.

• Pros: Robust design, high torque capacity, customizable gear ratios.
• Cons: High cost, requires sequential shifter, may require modifications to the transmission tunnel.

4. Tremec T56 Magnum

The Tremec T56 Magnum is a popular choice for high-horsepower builds due to its strength and relatively affordable price. This gearbox is originally designed for American muscle cars but can be adapted to fit the S13 with the appropriate adapter plates and modifications. The T56 Magnum is known for its smooth shifting and ability to handle significant torque.

• Pros: Strong, relatively affordable, smooth shifting.
• Cons: Requires adapter plates and modifications, may require transmission tunnel modifications.

5. Holinger Engineering

Holinger Engineering produces top-of-the-line sequential gearboxes that are used in the highest levels of motorsport, including Formula 1 and V8 Supercars. These gearboxes are incredibly strong, lightweight, and offer the fastest possible gear changes. While they are the most expensive option, they represent the pinnacle of gearbox technology.

• Pros: Incredibly strong and lightweight, fastest gear changes, used in top-level motorsport.
• Cons: Extremely high cost, requires extensive modifications.

Key Considerations During Gearbox Installation

So, you've picked out your dream gearbox! Proper installation is just as crucial as selecting the right gearbox. A poorly installed gearbox can lead to premature failure, even if it's a top-of-the-line unit. Here are some key considerations to keep in mind during the installation process:

1. Professional Installation

Unless you have extensive experience working on gearboxes, it's highly recommended to have the installation performed by a professional mechanic or specialist. Gearbox installation often requires specialized tools and knowledge, and mistakes can be costly.

2. Adapter Plates and Modifications

Depending on the gearbox you choose, you may need adapter plates to mate it to your engine and chassis. Ensure you source high-quality adapter plates that are designed specifically for your application. Additionally, be prepared for potential modifications to the transmission tunnel or other parts of the car to accommodate the new gearbox.

3. Clutch and Flywheel

Your clutch and flywheel also need to be up to the task of handling 1695hp. Upgrade to a high-performance clutch that can handle the increased torque. Consider a lightweight flywheel to improve throttle response and acceleration. Ensure that the clutch and flywheel are properly matched to the gearbox and engine.

4. Driveline Upgrades

With the increased power, your entire driveline will be under more stress. Consider upgrading your driveshaft and axles to handle the additional torque. A stronger driveshaft will prevent twisting or breaking under load, while upgraded axles will ensure that the power is effectively transferred to the wheels.

5. Cooling System

High-horsepower applications generate a lot of heat, and your gearbox is no exception. Consider installing a gearbox cooler to help dissipate heat and prevent overheating. This is especially important for gearboxes that are used in racing or drifting applications.

6. Proper Break-In Procedure

Follow the manufacturer's recommended break-in procedure for your new gearbox. This typically involves driving the car gently for a certain period to allow the gears to mesh properly and the bearings to seat correctly. Avoid harsh acceleration and high RPMs during the break-in period.

Maintaining Your Upgraded Gearbox

Once your gearbox is installed and broken in, regular maintenance is essential to keep it performing at its best. Here are some maintenance tips to keep in mind:

1. Regular Oil Changes

Change the gearbox oil at the intervals recommended by the manufacturer. Use a high-quality synthetic oil that is designed for high-performance gearboxes. Regular oil changes will help to keep the gears lubricated and prevent wear.

2. Inspect for Leaks

Regularly inspect the gearbox for any signs of leaks. Leaks can lead to low oil levels, which can cause damage to the gears and bearings. Address any leaks promptly to prevent further damage.

3. Check Gear Linkage

Ensure that the gear linkage is properly adjusted and lubricated. This will help to ensure smooth and precise shifting. If you notice any difficulty in shifting, have the linkage inspected and adjusted as needed.

4. Monitor Gearbox Temperature

If you have installed a gearbox cooler, monitor the gearbox temperature to ensure that it is operating within the recommended range. Overheating can cause damage to the gears and bearings.

5. Professional Inspections

Have the gearbox professionally inspected at regular intervals. A qualified mechanic can identify potential problems before they become major issues. This will help to ensure that your gearbox remains in good condition and performs reliably.

Conclusion

Upgrading the gearbox in your Nissan Silvia S13 is a critical step when aiming for 1695hp. The stock gearbox simply cannot handle the immense power and torque that comes with such a high-performance engine. By investing in a robust aftermarket gearbox and following proper installation and maintenance procedures, you can ensure that your S13 is capable of reliably putting down all that power. Whether you choose a PPG gearset, a Quaife sequential gearbox, or a Tremec T56 Magnum, the key is to select a gearbox that is designed for high-horsepower applications and to have it installed by a qualified professional. With the right gearbox, your S13 will be a formidable machine on the road or track. Happy building, guys!