EPA Friendly Part 3

Upgrading Our Emissions-Equipped LML

August 2017 Build, Duramax, Feature Brady L. Kay

Once you’ve added custom twin turbos and reached the 700hp club in an emissions-equipped Duramax, what possibly could be next? That was the question we proposed to Matt Rosenberg, owner of the 2016 Chevy Silverado LML and we were a little surprised to learn that he’s only getting started with his build. Seriously?

You would think the owner of Rosenberg Automotive & Diesel in southeast Idaho would be content after successfully accomplishing something a lot of people in our industry said couldn’t be done. However, it’s his drive to push the limits that has made Matt’s build what it is today with the help of some key players.

While many diesel owners opt for deletes as a workaround on the restrictions the Environmental Protection Agency (EPA) has placed on our industry, Matt wanted to legally see if 700hp was possible while keeping all his required emissions-equipment. Heading into his build he had more questions than answers, but trusted Wehrli Custom Fabrication in Sycamore, Ill., to get the job done.

Prep Work

Bone stock the truck sat at 347hp with 511 lb/ft of torque when Matt first purchased it and to lay the groundwork before taking his truck to Illinois he added a FASS 150 lift pump, Edge CTS 2 and BDS RECOIL traction bars. Before getting to the engine work, the guys at Wehrli rebuilt the transmission using the SunCoast kit to make sure the truck would be able to hold up to the increased power that was in its near future.  

In the second part of this build series we detailed the steps shop owner Jason Wehrli and his brother Ryan at Wehrli Custom Fabrication took to make it all possible.

“Anyone who looks under the hood might think it would be impossible to add another turbo without removing some of the components, but we made it happen,” recalls Jason.

“Because of room constraints we went down a size to the S300 frame turbocharger, with some special modifications to it. It’s not your typical S475 mainly because of the size and because we had less room to work with and had to go a little smaller.”

For injectors S&S Diesel Motorsport owner Greg Spoolstra recommended the 60 percent over injectors to help the Duramax reach its lofty goals and the shop also installed S&S Diesel’s CP3 10mm conversion stroker pump, which was a must for this project.


From here it was up to Nick Priegnitz, owner of Calibrated Power Solutions and home to Duramaxtuner.com in nearby Marengo, Ill., to build a tune for it.

“The biggest challenge on our end was matching the new air flow situation to the substantially larger, 60 percent over injectors without upsetting the emissions equipment on the truck. There’s a very small window of error; managing those injectors under hard throttle to minimize smoke out was a big challenge.”

The process was extremely successful and at that time the truck was sitting at an impressive 733hp and 1338 lb/ft of torque, proving 700hp is in reach for an emissions-equipped truck with the right team involved. At the Ultimate Callout Challenge back in April the truck took home first place in the Clean Power Hour challenge by reaching 749hp and 1372 lb/ft of torque on the dyno.

Added Lift

As the truck was leaving Illinois, Matt was impressed at how quiet and stock the engine sounded even with that big turbocharger, but wanted to do a few upgrades to the exterior to finish off his build so it wouldn’t be a total sleeper truck. For starters, the Chevy needed a little lift and since the LML owner was impressed with the BDS RECOIL traction bars he had installed earlier, he didn’t hesitate to go back to the suspension company.

The BDS Suspension 2- to 3-inch Coilover Conversion System was exactly what he was looking for. The kit upgrades the factory torsion bar suspension to coilovers and includes FOX 2.5 Factory Series DSC Coilovers. It also comes with heavy-duty upper and lower control arms as well as the next level ride quality and handling.

BDS operates with one guiding premise—to provide true value by engineering and manufacturing the highest quality aftermarket suspension lift kits, leveling kits and accessories and was the right fit for Matt’s build.
Seeing The Vision

Adding the 3-inch lift was just the beginning as Matt next upgraded the tires and wheels. Vision Wheel is one of those manufacturers who offer a great selection to choose from and has been doing so for over 40 years. Of course having so many top choices can be quite a challenge as you attempt to narrow down your choices, but it’s something most of us enjoy doing.   

After much deliberation, it was the 421 CANNIBAL wheels from Vision's Off-Road brand of custom wheels that Matt decided to go with. The 20-inch wheels provide the ideal balance of style for an aggressive and sporty look. 

Fabtech’s Heavy Duty Tie Rod assemblies are designed to resist bending and breakage when running oversized tires. So after adding the Nitto tires on the Vision wheels, the extra large diameter tie rods were a must. Each are forged and are superior in strength to the inherent weak factory tie rods that are known for bending under light off road use. The Fabtech Tie Rod assemblies directly replaced Matt’s factory tie rods without any modification needed to the centerlink or steering knuckles.

A Step Up

It’s easy to see how one upgrade leads to another and after adding the BDS lift with bigger wheels and tires, Bestop’s Powerboard NX with Wi-Fi controllers went from his wish list to his must-have list.

The Wi-Fi modules attach to the door jams and detect when any door opens or closes. They communicate to the wireless controller which then uses programmed logic to operate the boards independently. As far as installation, it was a lot faster and easier since the door panels didn’t need to be removed and Matt didn’t have to tap into the factory color-coded door wires inside the cab.

The biggest advantage is the Bestop electrically powered running board hide stealthily underneath your truck when the doors are closed and extends down about 6 inches to meet your foot when door opens.

PPE Has You Covered

Adding front and rear diff covers, plus a deeper tranny pan from Pacific Performance Engineering (PPE) was on his to-do list from the start, so Matt was glad when found the time to finally get around to adding them. Having larger capacities for your fluids makes all the difference when you tow a lot.

You tend to see a lot of PPE covers on trucks these days and for a good reason. The California-based manufacturer has built a solid reputation for building quality products that you can depend on. Founded in 1985 as a Diesel performance facility, PPE continues to strive in electronic high-performance diesel technologies for all diesel trucks.

While focusing on the underside of his LML, a skid plate for the DEF (Diesel Exhaust Fluid) tank from Fabtech was also added. The tank is located behind the passenger side front tire hanging down below the bottom of the frame. The location hasn’t gained a lot of favor with Duramax owners since it makes the tank vulnerable to impacts from flying rocks and the potential of being crushed from off-road obstacles. Fabtech offers a 3/16-inch thick steel skid plate that protects the plastic DEF tank from these types of hazards ensuring puncture and dent resistance for trouble-free off-road use.


The name says it all as the EZFold tonneau cover from Bestop really is easy to operate. The three-panel folding cover finished off the bed of the truck and when removed it still gives Matt full access to lager cargo. OEM quality, the heavy-duty adjustable clamps secure or release the cover with one-hand operation and the durable leather-grain textured vinyl is stretch and shrink resistant, withstands all climates, mildew and is UV resistant.

Facing Forward

To complete the no-chrome look he had envisioned from the start, Matt painted the bumpers and grille to color-match his truck then added a T-Rex insert that truly finished off the front end.

The T-REX Chevrolet Silverado HD X-METAL Series studded main grille is a two-piece all black design that includes black studs. With almost 20 years of cutting edge development, T-Rex Grilles is very well known for its aftermarket grille design and manufacturing work. Its dedication of American craftsmanship shows in every product that leaves its plant.

Of course at this point, leaving the stock headlights didn’t make a lot of sense—at least that’s what he was able to justify in his own mind—so Matt ordered Anzo headlights, taillights and a third brake light, which put the truck over the top. It’s the headlights specifically from Anzo that truly customized the look of the truck with the projector plank style with a black rim. It you want your truck to look unique, Anzo is always a popular choice.

Road Warrior             

When finished, not only did Matt drive his show truck to the UCC in Indianapolis, Ind., to compete but he also towed another diesel truck as well on the 3,500 mile round trip journey proving this truck truly was built to be used. While Matt plans to do a lot of towing with it, he still enjoys finding a back road out in the country and feeling the horsepower. 

“It’s like the pedal has no end,” says Matt. “I couldn’t be happier with the power this truck has. It will throw you back in your seat, which always puts a smile on my face.”

With the LML successfully back from the UCC after receiving a lot of feedback and positive compliments during the three-day event you’d think Matt would be completely satisfied with his build, but you’d be wrong.

“It’s definitely a step in the right direction but I think there’s still farther places to go with it,” explains Matt. “This was just the graduated steps we took to get it to the next level and where it goes from here I can’t wait to find out. It might just be a matter of looking at the fueling and perfecting what we already have.”

It seems like the greatest trucks are never truly finished, they’re always a work in progress and Matt clearly subscribes to that theory. Where it goes from here is anyone’s guess but you can be sure it will continue to turn heads wherever it goes.  








BDS Suspension



Curt Manufacturing



Duramax Tuner



Edge Products












Nitto Tires


Pacific Performance Engineering



Rosenberg Automotive & Diesel



S&B Filters



S&S Diesel Motorsport



SunCoast Diesel Transmissions



T-REX Grilles



Vision Wheel



Wehrli Custom Fabrication



  • Like what you read?

    Want to know when we have important news, updates or interviews?

  • Join our newsletter today!

    Sign Up
You Might Also Be Interested In...

Send to your friends!



Recapping the Vegas Show

Sneak Peek

Already a subscriber? Please check your email for the latest full issue link.