valvetronic engine technology - IFET College of Engineering
valvetronic engine technology - IFET College of Engineering
valvetronic engine technology - IFET College of Engineering
- No tags were found...
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
actual process <strong>of</strong> using energy mustreach a higher standard <strong>of</strong> efficiency.Despite modern <strong>engine</strong> <strong>technology</strong>, theprocess <strong>of</strong> on-going development has notyet come to an end. Looking at theoverall concept <strong>of</strong> a vehicle, thedevelopment <strong>engine</strong>er must thereforeoptimize the efficiency chain formed byall <strong>of</strong> the car’s individual components.For example, a car with a state-<strong>of</strong>-the-artspark-ignition <strong>engine</strong> uses only about20% <strong>of</strong> the energy consumed to actuallygenerate driving power and mobility inthe EU test cycle. This alonedemonstrates the remaining potentialEvolution <strong>of</strong> Valvetronic• the charge cycle;• friction; and• thermal losses through the walls.Optimisation in these areas indriving cycles with low loads and <strong>engine</strong>speeds provides the greatestimprovements in fuel economy. Quitegenerally, steps taken to reduce thethrottle effect have a greater potential forsaving fuel than the reduction <strong>of</strong> frictionin the drivetrain (see Figure 2.1).Precisely with this in mind, BMW haseveloped a fully variable valve drivereferred to as Valvetronic, a system<strong>of</strong>fering improvement in fuelconsumption comparable in virtually alldriving cycles to the latest spark-ignition<strong>engine</strong>s with direct fuel injection (DFI)and leanburn operation.The losses that are capable <strong>of</strong>being influenced are composed primarily<strong>of</strong> the following:• a combustion process not yet ideal;A number <strong>of</strong> other importantitems were also included in the list <strong>of</strong>objectives: • achieving dynamicperformance, fuel economy, noisemanagement and quality typical <strong>of</strong>BMW;• having a flexible concept capable <strong>of</strong>fulfilling future emissions standards;• creating a benchmark product in terms<strong>of</strong> its package, weight and cost <strong>of</strong>ownership;