FOR RELEASE: March 17, 2003
Jeff Kuhlman, Cadillac Communications
Kelly Cusinato, Cadillac Communications
David Caldwell, GM Product Communications
GM Powertrain has taken the Northstar 4.6-liter, dual-overhead-camshaft (DOHC) V-8 to a higher level of performance and refinement by developing a next-generation version of the highly regarded engine for the 2004 Cadillac XLR. The next-generation Northstar is the first adaptation to rear-wheel-drive (RWD) and all-wheel-drive (AWD) configurations.
"The next-generation Northstar was extensively re-engineered to provide drivers with a sophisticated, technologically advanced powerplant that will establish a new benchmark for luxury vehicles in performance, refinement and the total driving experience," said John Zinser, GM Powertrain Northstar chief engineer.
"This new Northstar does just that with smooth, refined performance throughout its entire operating range. It is quiet, yet tuned to give the driver feedback from the environment. It operates even more cleanly and efficiently than its predecessors with excellent reliability and durability."
While refined operating characteristics were a priority in developing the new Northstar, the overall goal was exceptional performance.
The Northstar delivers a higher output across the entire operating range with targeted output of 320 horsepower (239 kW) at 6400 rpm and 310 lbs.-ft. (420 Nm) of torque at 4400 rpm. In addition to these peak values, new four-cam continuously variable timing has freed the engine from the traditional constraints of fixed-cams that can only provide either high horsepower or high torque.
The Northstar also has an increased 10.5:1 compression ratio; while premium fuel is recommended for maximum performance, it can be operated on regular unleaded fuel.
New technology and design features
The Northstar V-8 is a 90-degree, DOHC, four-valves-per-cylinder engine featuring an aluminum block and cylinder heads, and a valvetrain configuration with roller finger followers. While maintaining these basic features, the new RWD version provides a host of Northstar "firsts," new technologies and design features to position it as a segment leader:
New Hydra-Matic five-speed automatic transmission
The Hydra-Matic 5L50-E five-speed automatic transmission, developed to manage the high torque and horsepower of the Northstar 4.6 liter DOHC V-8 in the XLR, is one of the most technologically advanced transmissions on any highway or autobahn in the industry.
The 5L50-E transmission is a modification of the Hydra-Matic 5L40-E transmission used in Cadillac CTS.
"The 5L50-E was designed specifically to manage the high torque and horsepower of the next generation Northstar 4.6 liter DOHC, while combining the convenience of an automatic transmission with the feel of a high-performance manual transmission," said Rich Mardeusz, GM Powertrain Hydra-Matic 5L50-E assistant chief engineer. "And it does it in the same size package as the 5L40-E."
To meet the performance demands of the new Northstar, the 5L50-E was designed to manage at least a 25 percent increase in horsepower and torque over the existing 5L40-E. Among its host of performance features, the 5L50-E gives drivers the ability to partially override the normal automatic gear selection for greater control when more aggressive driving performance is desired.
Key features of the new 5L50-E include:
The advanced performance capabilities of the powertrain in the Cadillac XLR is enabled by a sophisticated control system that performs functions beyond the scope of virtually any controller outside of NASA.
This control system gives the next-generation Northstar 4.6-liter DOHC V-8 unprecedented levels of power, performance and refinement, and provides the Hydra-Matic 5L50-E transmission with a host of capabilities, including the ability to switch from fully automatic to the characteristics of a clutchless high-performance five-speed manual.
The system is based on two new, extremely powerful controllers - the ECM and TCM are linked via an ultra-high-speed area network, the GM LAN protocol. The network also links them to all of the other critical vehicle performance functions, including ride, handling and brake control.
The ECM is a 16-bit, 24 MHz microprocessor, high memory control unit designed to integrate the engine’s unique VVT system for both intake and exhaust valve trains, ETC, and closed coupled catalysts for meeting emission requirements without secondary emission control systems.
In a sense, the TCM also has been integrated with the ECM since the functions of the two controllers are so closely attuned. The ECM also serves as the gateway between the GM LAN high-speed bus and the Class II functions via the body control module (BCM), which include chassis controls like anti-lock braking, traction control and adaptive suspension control.
Focus on quality
The meticulous attention paid to engineering detail in developing the new Northstar V-8 and Hydra-Matic 5L50-E is duplicated in its production at GM’s engine plant in Livonia, Mich., and transmission plant in Strasbourg, France.
In a major commitment to Northstar engine quality, GM has installed state-of-the-art equipment and machinery and adopted a new manufacturing strategy and innovative processes to produce Northstar engines.
Highlights of GM’s quality drive at Livonia include brand new engine assembly and cylinder head subassembly lines, upgraded machining operations, major increases in error proofing using new state-of-the-art technology and significant refinements and upgrades in the state-of-art cold test equipment used for final inspection.
The Hydra-Matic 5L50-E transmission facility in Strasbourg is also known for its painstaking approach to quality and the excellent warranty record of its products.
This commitment to quality is reflected in its assembly environment: transmissions produced at Strasbourg are hand assembled in a clean room. This approach alone has a positive impact on quality and warranty issues.
The chances of foreign matter being introduced into the transmission are minimized because assembly takes place in a clean room atmosphere. Only assemblers are allowed in the clean room and care is taken to be sure they don’t track in dirt or dust. Components are delivered through sliding Plexiglas windows without the handlers ever entering the area.
A heritage of innovation
The RWD Northstar continues the tradition of innovation. With 16 patents when first introduced in 1992 and several in subsequent years, the FWD Northstar set new standards for luxury-car power, refinement and durability.
Continuous improvements in subsequent years were followed by a major upgrade in the 2000 model year. Highlights of the upgrade included adoption of a low friction valve train with roller finger followers for better economy and a low restriction intake manifold for quieter operation and emissions improvements. The FWD version of the Northstar will continue to be available for selected Cadillac applications in 2004.
Article ID: 33
Created: December 20, 2016
Last Updated: December 20, 2016
Author: Rob Loszewski
Online URL: https://www.xlr-net.com/knowledgebase/article/march-17-2003-next-generation-northstar-sets-new-standard-in-performance-and-refinement-for-2004-cadillac-xlr-33.html