Project LBZ Part 2

Fuel Injectors & Manifolds

Fuel injectors are one of the key choke points that can have a radical affect on the performance of the engine. With the impending compound turbo we planned to install during the engine rebuild, changing out the stock injectors is a must. Working together on Project LBZ, we contacted Dynomite Diesel Products for a set of custom fuel injectors to overcome this limitation.

Dynomite Diesel Products offers customized aftermarket parts as well as a drive-in repair and installation facility. DDP supplies a wide range of fuel related parts for Cummins, Duramax and Power Stroke engines. These injectors are some of the most popular because of their high-quality precision that delivers clean power at a consistent flow.

“We start with new OEM based injectors,” says Brian Bailey, injector sales and support at Dynomite Diesel. “Even brand new injectors right out of the box may have a five to eight percent variation in fuel delivery from injector to injector at wide open throttle on the test stand. After we install our custom honed nozzles and balance the injectors, they typically flow within one to two percent of each other at wide open throttle.”

Project LBZ’s fuel injectors are a custom set equipped with nozzles honed to 19 liters per minute. On the test stand these injectors flowed 78.2cc to 80.3cc at wide open throttle. “Now compare this to a stock LBZ injector which has a 17 liter per minute nozzle and typically flows around 70cc on the same test stand,” continues Bailey. “It may not sound like a huge difference in flow, but the performance at the end of the day is undeniable.”

At Dynomite Diesel they have many different size injectors from stock to all out competition-only injectors. In our case we had initially planned on larger injectors, but after consulting with them it was decided we would be best suited with a custom injector.  These injectors have a smaller nozzle to keep smoke and EGTs down, yet still deliver the top-end performance we’re after.

With the increased fuel injection, half of the performance equation was tackled. Moving outward, we next replaced the stock manifolds with parts from ATS Diesel Performance.

The stock manifolds of the LBZ showed little signs of age; however, they create turbulence from the configuration and design which reduces proper airflow and negatively affects performance. Not wanting equipment restrictions to plague our truck once finished, we looked to ATS to help fix our looming airflow choke point.

A well-established diesel performance shop located near Denver, Colo., with a large, in-shop machine fabrication plant, ATS is a model for self-sufficiency, preferring to control nearly all aspects of its production in house, rather than having to outsource their work and parts. Their manifolds offer 30 percent increased air flow, accomplished through an increased diameter of the manifold. This forces more air through, as well as the exit angle of manifold, eliminating the turbulence created by the design of the stock manifolds. Further, ATS uses a high silica molly, adhering to the same metallurgical mix of the heads to ensure that the parts shrink and expand the same as stock parts under the stress of pressure, compression and temperature of the engine.