Page 271 - 05. Subyek Teknik Mesin - Automobile Mechanical and Electrical Systems Automotive Technology Vehicle Maintenance and Repair (Vehicle Maintenance Repr Nv2) by Tom Denton

2
Engine systems 255

Vehicle
Operating Start Up Acceleration Cruising Deceleration Idle
Mode

Motor Engine Engine Generation Regeneration Idle Stop
Function Start Assist

Reduce fuel
Fuel Best fuel consumption by
Efficiency Reduce engine
control when Recover and halting the
starting load and fuel Reduce store generated engine during
consumption by unnecessary idle
motor assist energy
generation and
load by efficient
battery control

Figure 2.347 Operating conditions

High
No generation No charging
Engine & wide open Auto stop
Assist with
State of charge (SOC) throttle Generate for Regeneration
Startup by
partial load
system
IMA
12 V vehicle

Wide open
throttle assist Generate for
recharging
Startup by
starter motor No assist Generation

Figure 2.348 Integrated motor assist (IMA) operating details

The IMA technique used by most hybrid cars can be thought of as a kinetic
Key fact
energy recovery system (KERS). This is because instead of heat energy from
the brakes being wasted as the vehicle is slowed down, some is converted to The IMA system is a kinetic energy
recovery system (KERS).
electrical energy and stored in the battery as chemical energy. This is then used
to drive the wheels, so saving chemical energy from the fuel. However, hybrid
vehicles still need exhaust extraction ( Fig. 2.349 ).

2.8 Formula 1 engine technology

2.8.1 Engines overview
Key fact
Formula 1 currently uses four-stroke V8, 2400 cc, naturally aspirated engines ( Fig. Formula 1 currently uses four-stroke
2.350 ). These produce in the region of 224 kW (300 bhp, 304 PS [metric hp]) per V8, 2400 cc, naturally aspirated
litre of displacement. This is much greater than most road car engines. This huge engines.
power output is partly due to being able to operate at a very high rpm. Engines of
a similar size in road vehicles typically operate at less than 7000 rpm. The torque