Addressing the fuel side of Duramax performance upgrades with hotter injectors
INCREASED AIR and fueling comprise the short list of contributors to hopping up diesel engines. Of course, limiting performance gains to those two entities is grossly oversimplifying things, but you get the picture. No matter which powerplant is under the hood, its limiting factors are the same: The stock turbocharger can only flow so much air and OEM injectors so much fuel. Once they’re maxed out, it’s time to upgrade.
With our ’02 Chevrolet Silverado 2500HD’s 6.6L Duramax LB7 engine’s air and fueling already upgraded by a Fleece Performance Engineering Cheetah turbocharger and a 42-percent-over CP3 injection pump from Industrial Injection, we know the next step toward our LB7 putting 650 hp on the ground is replacing its original injectors.
For this, we turned to the experts at Dynomite Diesel Products, a company that has been in business for nearly two decades and either builds, modifies, or services fuel injectors for practically all the modern diesel-pickup engines—and even a few less-than-modern units. If you
frequent the diesel drag-race or sled-pull scenes, you’ll recognize the company’s products powering some of the fastest and most powerful trucks on the circuit.
Diesel injectors are rated two ways: in horsepower over stock and percentage of flow over stock. To allow a little wiggle room for future improvements, we opted for the company’s 100hp injector set, which flows 60 percent more fuel. Dynomite claims the squirters will support up to 800 hp, and we should see a 1-mpg increase in fuel economy as well.
Installation is straightforward and follows any normal injector-service protocol. A pyrometer is recommended to keep tabs on exhaust gas temperature using any injector with a flow rate greater than factory. While small nozzle upgrades can be made with no adjustment to tuning, at the level we’re running, it’s suggested that aftermarket tuning be employed.
LB7 injectors are known to be the most troublesome of the entire Duramax family. Fortunately, Bosch has continually improved the injectors’ design and now produces squirters that are far more reliable. Still, even the best LB7 injectors need servicing...
1. Dynomite Diesel Products’ upgraded injectors are nothing short of beautiful. Like kids on Christmas, we enjoyed opening each and every one of the individual boxes, even though we knew what was inside.
2. There’s no mistaking a DDP injector. The company’s logo is laser-etched into the body.
4-5. It’s important to remember to install the two O-rings. One goes on the injector body and the other on the high-pressure fuel inlet. You’ll want to lube the body’s O-ring with clean oil before dropping it into the cup.
3. Everything needed to install the new injectors (O-rings, copper washer) is included.