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The updated 850 Series Holset turbocharger offers a new compressor stage that provides more-efficient and aerodynamically focused performance. (Cummins) 

Cummins spools up new turbo tech

Cummins’ latest generation of Holset turbochargers offer increased efficiency and output for on- and off-highway applications.

Cummins Inc. and Holset Turbocharger announced several technical revisions to their Series 850 turbocharger. The Series 850 turbo is intended for customers with high-horsepower engines ranging from 15-L to 95-L (15L to 25L per turbocharger). The series 850 is manufactured in Huddersfield, UK and is intended for a wide range of off-highway applications including power generation, agricultural, mining, oil and gas, rail, construction and marine. 

The latest 850 reportedly offers a new compressor stage that makes for a more efficient and aerodynamically focused product. Like its predecessor, the Series 850 includes Cummins’ advanced High Pressure Ratio Compressor (HPRC) technology. This technology was first released in 2020. According to Cummins, this design increases turbo flow range capability by up to 25%. 

This increase in flow reportedly has allowed customers to uprate engines by as much as 25-40% without the need to move to a 2-stage architecture. Cummins also states that this technology enabled additional altitude capability for many applications. The HPRC technology reportedly improves overall efficiency at a 4.5:1 pressure ratio, which during simulated tests has resulted in 5% to 7% brake-specific fuel consumption (BSFC) improvements for existing applications. 

The latest Series 850 also features a new inverse impeller design that has been optimized to provide higher performance with improved durability. The 850 is available with either a vaned or vaneless diffuser. The vaneless design offers enhanced map width at higher pressure ratios, whereas vaned design offers efficient higher pressure ratio capability with flexibility to improve usability by altering vane designs. The latest 850 turbos also feature a thin wall stainless steel compressor cover which reduces component weight compared to cast iron designs. 

"Our Holset Turbochargers are continuously incorporating new technology to improve our products and exceed performance expectations for on-and off-highway customers,” said Lalitkumar Suryawanshi, director, high horsepower products. “With additional altitude capacity, improved product efficiency and higher power density, the Series 850 is designed to meet emission requirements and drive value for customers.”  

A new generation 
In addition to launching the new Series 850, Cummins is also preparing to introduce the 8th generation series 400 Holset variable geometry turbocharger. Scheduled to launch in 2024, the HE400VGT is intended for the 10- to 15-liter heavy-duty truck market and reportedly features significant improvements in performance. 

Cummins states that the 8th-gen 400VGT is five percent more efficient than the outgoing version and offers improved transient response, enhanced compressor side oil leak robustness and dual sourcing on key components for supply chain flexibility. 

Other technical highlights of the HE400VGT include a new bearing system and near-zero clearances to enhance overall performance. According to Cummins, these enhancements are achieved by tighter clearances on the compressor stage, lower radial movement on the turbine stage, improved surface finish and new aero designs. The 400VGT also incorporates a smart electric actuator and speed sensor. 

“Cummins has incorporated exciting new technologies in our latest HE400VGT to help engine customers meet strict emissions requirements and reduce their total cost of ownership,” said Matthew Franklin, director – product management & marketing. As customers establish their strategies for upcoming emission regulations, CTT continues to build on the success of previous turbocharger launches to deliver innovative products that meet the challenges of our customers’ engine development needs without compromising on performance.” 

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