Interim Tier 4 and Tier 4 Technologies
In 2012, the Federal Interim Tier 4 (iT4) emission regulations will only affect compact equipment using 75.1 to 174.3hp engines.
The Bobcat® machines affected are the seven compact loader models offered in the 700 and 800 platforms. This represents 15% of Bobcat's total product offering, while 85% of Bobcat machines are unaffected by emission regulations in 2012.
Electronic Control Unit
The Electronic Control Unit (ECU) is new to iT4-compliant 700 and 800 platform machines. It reduces emissions, noise and operating costs while improving performance. The ECU offers several benefits:
Better Productivity: With electronic capabilities of the iT4 ECU, engine RPM recovery is faster when transitioning between torque and horsepower demands. Operators will experience shorter cycle times and better productivity when performing tasks like digging, grading or lifting materials.
Increased Travel Speed: The ECU enables horsepower management (a feature included with Selectable Joystick Controls) to control the loader's drive system based on engine torque. This minimizes engine stalling and provides up to 150% more travel speed at low- to mid-range engine RPM.
Lower Operating Costs & Reduced Noise: The ECU allows an auto idle function with SJC-equipped machines, providing quieter operation and reducing fuel consumption. This feature can be set to auto-activate, lowering engine RPM to idle if the loader's functions are not used for 5 seconds.
Reduced Emissions: The ECU controls the clean diesel technologies incorporated into the iT4 700/800 platform loaders resulting in cleaner exhaust.
Diesel Oxidation Catalysts (DOC) and Diesel Particulate Filters (DPF)
DOC/DPF systems are highly effective at removing particulate matter from exhaust and are incorporated into Bobcat 700 and 800 platform loaders.
High Pressure Common Rail Fuel System (HPCR)
The fuel injection system is a major area of focus for advancement towards clean operating diesel engines. HPCR, a system used in the iT4 compliant 700 and 800 platform loaders, is an advanced fuel injection design that regulates fuel pressure and injection timing.
- The pump applies high pressure to fuel (22,000 – 34,000 psi)
- The common rail stores pressurized fuel
- The injectors deliver fuel to the engine
The electronic control unit (ECU) precisely controls injectors to allow multiple fuel injections during each combustion cycle.
High pressure transforms fuel into extremely fine mist as it leaves the injectors. Fuel mist combusts (burns) more thoroughly.
- Cleaner Exhaust: More thorough combustion leaves less leftover fuel in the exhaust. The result is cleaner exhaust.
When fuel is injected multiple times during each combustion cycle, the combustion lasts longer to create more energy and lower peak engine cylinder pressure.
- Better Performance: Creating more energy during combustion results in more torque output from the engine.
- More Operator Comfort: Lower peak engine cylinder pressure reduces engine noise levels.