David Schaefer’s 2015 GMC 2500HD Denali, known as "Time Bomb," is a remarkable achievement in the world of diesel performance. With a stunning 700 horsepower while maintaining full emissions compliance, this truck is a testament to what can be accomplished with thoughtful engineering and high-quality components. Let’s break down this comprehensive build, exploring the features that make it special and how they come together to create a never before achieved driving experience. 

The Vision Behind Time Bomb

David purchased the Time Bomb in 2018, initially bone stock, intending to explore performance while keeping the emissions system intact. As diesel regulations tightened, he recognized the importance of understanding and working with the emissions systems rather than against them. This proactive approach would allow him to maximize performance without sacrificing compliance, making his truck a forward-thinking build in an ever-evolving industry.

The Previous Setup

In the early stages, David's truck featured only tuning from DuramaxTuner and a FASS 165 lift pump. This foundational setup provided a taste of performance but was limited to low to mid-600 horsepower. While satisfactory, David envisioned a truck that would stand out both visually and in power.

Current Engine Build

The goal for this build was clear: achieve over 700 horsepower while maintaining factory-like regen intervals. The strategy involved optimizing fuel and air systems to ensure every component worked synergistically.

Under The Hood

Turbocharger: The upgrade to an S372SXE turbo allowed for increased airflow, enhancing both responsiveness and overall power. This turbo is crucial for reaching the truck’s performance goals while keeping emissions intact.

Injectors: Exergy 20% over injectors were selected to provide adequate fuel flow without compromising emissions control. Coupled with a 10mm CP4 pump, this combination delivers the necessary power while minimizing soot production.

Custom Air Intake: The WCFab custom intake kit, specifically designed for the L5P hood swap, is a one-of-a-kind feature of this build. It improves airflow and aesthetics, integrating seamlessly into the engine bay.

Exhaust Flow: High-flow exhaust manifolds and custom WCFab twin turbo high-flow up pipes with EGR leg were installed to maximize exhaust flow and turbo response. These components work together to reduce back pressure, facilitating quicker spool-up and improved efficiency.

Tuning

With the hardware in place, Calibrated Power worked to fine-tune the engine, resulting in dyno numbers exceeding 700hp and 1200ft-lbs of torque. This tuning is critical for balancing power with emissions compliance, ensuring lambda values remain within an acceptable range.

Exhaust System

The exhaust features a Banks Monster Exhaust System, known for its ability to enhance exhaust flow and sound. This upgrade not only contributes to performance but also ensures a throaty, aggressive tone that complements the truck’s power.

Supporting Modifications

During the engine build, David addressed several other critical components of the truck to enhance performance and reliability:

Transmission: The factory transmission was upgraded to a Cold Front Diesel-built unit with a 750HP capacity. This included new clutches, steels, and a Goerend X Stall torque converter, ensuring it could handle the increased power without issues.

Suspension: A SuspensionMaxx leveling kit, paired with King 2.5 reservoir shocks, was installed to improve ride quality and handling. The Kryptonite Ultimate Front End Kit and Kryptonite Upper Control Arms enhance durability and steering precision, making the truck capable of tackling tough terrains.

Wheels and Tires: David upgraded to Liberty Forged LBTY21 wheels (22x12 polished) wrapped in Michelin Defender LTX tires. This combination offers a smooth ride and excellent traction, proving that high performance can coexist with comfort.

Frame and Body: Stiffening up the frame of this build is a set of WCFab traction bars. The factory undercoating was also removed, imperfections smoothed out, and the frame was repainted. This attention to detail adds longevity to the truck while enhancing its overall appearance.

Lighting: Custom Diode Dynamics rock lights were installed throughout the chassis, providing functional lighting and a unique aesthetic touch. The wiring was meticulously organized to maintain a clean look.

Unique Features and Innovations

Time Bomb isn’t just about raw power; it showcases unique features that set it apart from the crowd:

One-of-a-Kind Components: The custom intake setup and high-flow up-pipes with EGR leg are unique to this build, showcasing the craftsmanship of WCFab. This level of customization ensures optimal performance and an aesthetically pleasing engine bay.

Innovative Use of Technology: David’s decision to utilize the stock L5P hood while retaining its ram air function demonstrates forward-thinking engineering. This decision came with its own set of challenges, but the results speak for themselves.

Efficient Emissions Control: David has successfully maintained impressive regen intervals—660 to 724 miles—while towing heavy loads with minimal DEF usage. This balance of power and efficiency highlights the effectiveness of the emissions system.

Performance in Action

Since the build’s completion, David has extensively used the Time Bomb for towing a 32’ tri-axle gooseneck trailer, fully testing its capabilities. The truck has so far undergone three regen cycles with intervals of 660, 724, and 692 miles, showcasing its ability to balance power with emissions compliance effectively.

A Testament To Emissions On Performance

David Schaefer’s Time Bomb is a remarkable example of what can be achieved when passion, knowledge, and quality parts come together in a diesel truck build. By prioritizing emissions compliance and performance, this truck stands as a model for enthusiasts who want to push boundaries without sacrificing responsibility.

With the expert tuning and components from Calibrated Power and Duramax Tuner, David has created a truck that not only performs but also protects him from any legal ramifications in the future. The Time Bomb build is not just another powerful vehicle; it’s a testament to innovation in the diesel community, paving the way for future builds that embrace both performance and compliance.