This week marks the merger of two powerful forces from within the diesel community. For many in the diesel world, this news feels less like a new chapter and more like the natural continuation of a partnership that has already shaped the industry. For over 15 years, Nick Pregnitz, owner of Calibrated Power Solutions and Jason Wehrli, owner of Wehrli Custom Fabrication (WC Fab) have worked side by side, blending their passions for every aspect of diesel performance and partnering together on many builds that have redefined what modern diesel performance could be.

Today that force has become stronger as Jason Wehrli has now acquired Calibrated Power Solutions with Nick Pregnitz continuing to lead and drive the product creation and innovation for the foreseeable future. While allowing the two companies to combine their many years of tuning turbocharger, and transmission expertise with cutting-edge design and fabrication.

A Proven History of Collaboration

From the earliest days, the teams at Calibrated Power and WCFab have shared a vision of pushing diesel performance forward. That collaboration has led to some of the industry’s most ambitious and innovative projects.

One standout is David Schaefer’s 2015 GMC Denali, known as “Time Bomb.” Built with Cold Front Diesel, this emissions-intact LML build made waves by breaking the 700-horsepower mark while maintaining factory-like re-gen intervals. With WCFab’s custom intake and exhaust components paired with DuramaxTuner’s precision calibration, Time Bomb proved that performance and compliance don’t have to be at odds.

“Over the past 15 years I and the Calibrated Power team have worked with Jason and his team on a variety of projects,” said Calibrated Power Founder Nick Priegnitz. “From land speed record attempts, to a big block UCC build, to a custom emissions-equipped compound turbo kit—we’ve pushed limits together every step of the way.”

Beyond Time Bomb, the partnership has also fueled:

• A triple turbo 10.4L Cummins sled pull truck, built for all-out power.

• An LB7-powered land speed record attempt, pushing boundaries on the track.

• Creating the first emissions-on compound turbo kits, proving innovation can be both bold and compliant.

These projects showcase not only the trust between the two companies but also the results that come from aligning engineering, tuning, and fabrication expertise.

What This Means for the Diesel Community

For diesel enthusiasts, the strengthened partnership means more than just new products—it means better solutions delivered faster and with greater reliability.

Here’s what you can expect:

• Faster Innovation – Integrated design, fabrication, calibrations and processes will streamline product development.

• Proven Performance Packages – More complete systems, engineered and tested together, ensuring seamless results on the street and under load.

• Commitment to Emissions-Intact Performance – Builds like Time Bomb prove what’s possible, and the combined teams will continue leading the way in delivering compliant horsepower without compromise.

• Reliability at the Core – Both brands have built reputations around usable, repeatable performance that lasts. This partnership doubles down on that promise.

 

“This partnership exists for the customer,” explained Nick. “Combining the best of our engineering, design, validation, and tuning teams makes for a very exciting future that I fully intend to be a part of.” - Nick P. (Calibrated Power Founder)

 

 

Continuing the Mission

Both Calibrated Power and WCFab will continue operating independently, with their own teams and facilities. What changes is the opportunity to collaborate even more closely—sharing resources, ideas, and validation processes to accelerate the next generation of diesel solutions.

Nick will remain at the helm of technical product development and calibration strategy, ensuring that Calibrated Power’s foundation of innovation and drivability remains as strong as ever.

“We’ve always believed in building for the long term,” added Priegnitz. “That means innovation that’s tested, validated, and reliable. With WCFab, we now have the resources to accelerate that process while keeping our standards higher than ever.” 

Future projects are already underway, including expanded support for the 2024+ L5P Duramax and 2023+ 6.7L Power Stroke, along with continued growth of the Stealth Turbo line, which has become a benchmark for drivability and emissions-compliant power.

About the Companies

Calibrated Power Solutions
Privately owned and operated since 2008, Calibrated Power Solutions is a leader in the diesel aftermarket industry. Based in Woodstock, Illinois, the company delivers custom performance engine calibrations and turbocharger upgrades under its Duramaxtuner and Stealth Turbo brands, focusing on balancing drivability, reliability, and power.

Wehrli Custom Fabrication (WCFab)
Privately owned and operated since 2010, Wehrli Custom Fabrication has grown into a 112,000-square-foot facility in DeKalb, Illinois. The company specializes in precision CNC machining, custom metal fabrication, powder coating, and performance upgrades for Duramax, Cummins, and Power Stroke diesel trucks.

The Road Ahead 

With Calibrated Power and Wehrli Custom Fabrication both standing at on front of innovation in their fields. This strengthened partnership is simply the next logical step in a long journey of working together, solving problems for diesel truck owners, and setting new standards for performance.

The best is yet to come—and we couldn’t be more excited to share it with you!

Learn more about the companies and sign up for their news letters now at:

• Wehrli Custom Fabrication
• Calibrated Power

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