High Power Density
Jacobs’ High Power Density® (HPD®) technology provides the lightest, most cost-effective, highest power retarding technology available.
Performance benefits of Jacobs’ High Power Density technology
Double the braking power at cruise speeds
The engine brake power is significantly increased at lower engine speeds compared to conventional compression release brakes.
Increased payload for the retarding performance you need
Our integrated, simple design allows for reduced package and mass as compared to other vehicle retarding solutions such as hydraulic driveline retarders. This results in increased payload by providing all the vehicle retarding performance you need from the engine.
Lower total cost of ownership
While providing increased foundation brake life, truck uptime, and higher resale value, Jacobs’ HPD technology comes at a fraction of the cost of comparable driveline retarder devices that offer similar power.
Jacobs HPD: The Evolution of the Engine Brake
The constant evolution of engine, powertrain, and complete vehicle technology requires an engine brake that can answer increased retarding demands. Developed to complement these technology trends and help further future developments, Jacobs’ HPD delivers the retarding power needed to:
- Compensates for decreased aerodynamic drag and decreased rolling resistance of the latest trucks
- Compensates for the trend toward lower engine speed operation and specification of smaller displacement engines
- Operates at the engine speeds you use, so you avoid downshifting during retarding
In addition, HPD control is fully integrated into the engine ECM and is completely compatible with the latest developments in cruise control and safety features.
How Jacobs’ HPD technology works
Jacobs' full 2-Stroke HPD technology realizes up to 1.5 times the available braking performance of a conventional compression release engine brake. This technology can apply not only to smaller displacement engines but will also maximize the performance of your current engine.
Jacobs Modular HPD System
Standard Compression Release
- Standard dedicated cam compression release braking system
- Hardware includes rocker brake, normal exhaust and intake bridges, BGR/CR cam, and brake rocker biasing
- Standard performance based on the air handling and load carrying capability of the engine
1.5 Stroke HPD
- Hardware includes the same standard rocker brake, cylinder deactivation bridge on exhaust main event, cam design with multiple CR/BGR events, and exhaust biasing
- Performance throughout the full RPM range is significantly improved from standard braking-efficient upgrade that does not require significant changes to the overall valvetrain
- Cost-efficient upgrade that does not require significant changes to the overall valvetrain
2 Stroke HPD
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Hardware includes rocker brakes and cylinder deactivation bridges on intake and exhaust, cam design with optimized intake/exhaust events, and full rocker biasingIntake optimization for HPD improves airflow and increases performance, especially at low RPM
- Slightly more complex system to achieve highest performance level possible
- Provides capability for full cylinder deactivation
Natural Gas Engine + HPD Engine Brake
The smaller turbo and smaller compression ratios of natural gas engines negatively impact the brake retarding power by up to 25%. Jacobs' High Power Density Engine Brake makes up for this loss so fleets can still safely haul standard load sizes.
Tech Talk: HPD
Dive deeper into High Power Density engine braking. Watch our HPD Tech Talk to learn more about how the HPD engine brake works, its performance, its benefits, how it compares to a driveline retarder, and how it improves engine braking for natural gas engines.
