lmm s400 Kit: Complete Guide to the High Performance Duramax Turbo Upgrade

Introducing the lmm s400 Kit: A Powerful Duramax Upgrade

Diesel truck enthusiasts are always looking for ways to get more power and performance out of their rigs. One popular upgrade for Duramax-powered trucks is the lmm s400 kit. This kit is designed specifically for 2006-2010 GM trucks equipped with the 6.6L Duramax LMM diesel engine. In this article, we’ll take an in-depth look at what the lmm s400 kit is, who it’s for, and the benefits it offers for your truck.

What is the lmm s400 Kit?

The lmm s400 kit is an all-in-one package that takes the LMM Duramax to the next level. It includes a larger s400 turbocharger, upgraded fueling components, and all the necessary gaskets, tubing, and hardware for a complete install. The star of the show is the massive 64mm compressor wheel within the Schwitzer s400 turbo. This swallows huge mouthfuls of air and delivers increased boost pressure to the engine. Combined with the included fueling upgrades, the lmm s400 kit can safely support over 800 horsepower.

Who is the lmm s400 Kit Designed For?

This kit was created with Duramax enthusiasts and power-adders in mind. It’s intended for use on 2006 to 2010 model year trucks equipped with the 6.6L LMM Duramax engine. That includes Chevy Silverado 2500/3500 HD models, as well as GMC Sierra 2500/3500 HD versions. Whether you’re looking to tow or haul heavier loads, blaze through the quarter mile, or simply want the ultimate performance diesel, the lmm s400 kit delivers.

Benefits of Adding the lmm s400 Kit

Installing the lmm s400 upgrade kit brings some major benefits, including:

• Increased Horsepower & Torque
• Greater Towing Capacity
• Improved Fuel Efficiency
• Lower Exhaust Gas Temperatures
• Better Driving Experience

The 64mm compressor wheel flows a massive amount of air compared to the factory LMM turbo. This supports increased boost levels to unleash a lot more power. Expect gains of 200-300 horsepower or more at the rear wheels after tuning.

In addition to power gains, the larger s400 turbo drives exhaust gasses more efficiently. This keeps exhaust gas temps lower at high engine loads for improved engine life. And with the ability to wring more power from less fuel, you’ll enjoy enhanced fuel mileage when cruising the highway.

s400 Turbocharger - The Heart of the Kit

The Schwitzer s400 turbo sits at the core of this kit. It bolts up to the factory LMM exhaust manifold using supplied hardware. A 4” downpipe with flex section routes spent gasses rearwards. The s400’s 64mm billet compressor wheel flows nearly 40% more air than the factory LMM turbo. This feeds the engine a denser air charge, supporting higher boost levels without sacrificing response. The dual ball bearing center section ensures smooth and efficient operation even at high RPMs.

Fueling Upgrades Keep Things Safe

Bolting a much larger turbo onto the engine requires fueling upgrades to support the extra flow. The lmm s400 kit includes a CP3 high pressure fuel pump to supply the increased fuel demand. It also comes with 100% over injectors that bolster fuel delivery. To control the injection events, a smart Fuel Pressure Relief Valve is added. This regulates fuel rail pressure based on load and duty cycle. All of these upgrades work together to provide robust fueling for big power.

Installation Requirements

While the lmm s400 kit includes all the main components, there are some requirements for completing the install:

• Aftermarket Tuner - Required to take full advantage of the upgrades
• Exhaust System Modifications - Usually mandrel bent piping with muffler
• Boost/Pyro/EGT Gauges - Monitoring capability for engine vitals
• Transmission Upgrades - Often needed for trucks over 650hp

Professional dyno tuning is a must with an upgraded turbo kit. This allows the tuner to dial in the ideal fuel maps and timing for maximum power gains and engine longevity. Some minor exhaust modifications are also needed to accommodate the new 4” downpipe. And gauges help keep tabs on safe boost, EGT, and pyro levels while towing or racing. For trucks pushing past 650hp, built transmission upgrades help get all the power to the pavement.

Installation Overview

Here is a general overview of installing the lmm s400 kit:

1. Remove factory turbo, fuel pumps, and injectors
2. Install new fuel pumps, lines, and injectors per instructions
3. Mount new s400 turbo and connect oil/coolant lines
4. Fabricate new downpipe and intake tube
5. Install all sensors and connect turbo outlets
6. Modify exhaust and intake systems as needed
7. Get professional dyno tuning

The whole process takes around 20 hours for someone with diesel mechanic experience. Proper planning is crucial, along with having all the required tools, fluids, and equipment on hand. Taking time to do things right will ensure optimal performance and longevity from the upgrades.

Maintaining the s400 Turbocharger

Like any forced induction system, the s400 needs proper care and maintenance. Here are some tips for keeping your turbo healthy:

• Allow proper warm up and cool down time
• Use thick 10w-40 or 15w-40 engine oil
• Change oil at 5,000 mile intervals or less
• Install an oil catch can to reduce deposits
• Only use manufacturer approved turbosmart oil
• Check and replace turbo gaskets if any oil leaks develop

With proper care, the Schwitzer s400 turbo can support well over 800hp reliably. But neglecting maintenance will quickly lead to premature wear or even total failure.

Expert Tuning is Key

Having a well-executed custom dyno tune is absolutely vital when upgrading to an s400 turbo kit. Here are some reasons why professional tuning is so important:

• Prevents engine damage from too much fuel or boost
• Optimizes power output across the RPM range
• Improves throttle response and drivability
• Maximizes fuel economy when cruising
• Allows adjusting parameters for towing or performance
• Diagnosing and correcting any issues after install

With hundreds of parameters to tweak, expert tuning knowledge is required to dial in these kits. Investing in a proper dyno tune will ensure maximum performance and engine longevity when running big boost.

Dyno Proven Duramax Power

The lmm s400 turbo kit is dyno proven to support some mammoth power numbers. With supporting fuel and transmission upgrades, trucks make 750+ horsepower to the wheels. The larger 64mm compressor flows substantial air to help unlock the LMM's potential. While not for the faint of heart, this kit provides Duramax engines with race-inspired capability.

Conclusion

For those seeking ultimate diesel performance, the lmm s400 turbo kit delivers in spades. With supporting fuel system upgrades, this turbo swallows huge gulps of air to support 800+ horsepower. Drivability improves both towing and unloaded thanks to the wide powerband. And properly installed with expert tuning, this upgrade unlocks the LMM Duramax's massive potential. Just be prepared for stunned faces at the diesel drag strip!

FAQs

What vehicles is the lmm s400 kit compatible with?

The lmm s400 kit is only compatible with 2006-2010 GM trucks equipped with the 6.6L LMM Duramax diesel engine. This includes Silverado 2500/3500 HD and Sierra 2500/3500 HD models.

What kind of power gains can I expect from the lmm s400 kit?

With proper supporting mods and custom tuning, the 64mm s400 turbo can support over 800hp at the wheels. Typical gains are in the 200-300hp range over stock.

Do I need to upgrade my transmission with this kit?

For trucks making over 650hp, a built transmission is highly recommended. The extra power can quickly overwhelm the stock components leading to failure.

What tuner is required to run this turbo kit?

Aftermarket tuners like EFI Live, H&S Mini Maxx, or Smarty are recommended. Expert dyno tuning is crucial to dial in the power gains safely.

Will the s400 turbo work with my stock LMM turbo manifold?

Yes, the s400 turbo is a direct bolt-on replacement for the factory turbo/manifold. No manifold modifications are required for installation.