BMW ( VALVETRONIC)

2014 BMW I8.

ENGINE MODEL i8

Behind the bodywork and aluminum frame is both a BMW Twin Power in-line three-cylinder combustion engine that powers the rear wheels and a hybrid synchronous motor that powers the front wheels. The all-wheel drive hybrid claims a top speed of 155mph (expect a later unrestricted M variant). Even more impressive is the 94mpg and CO2 rating of 59 g/km. The gasoline four-valve in-line three-cylinder alone generates 231hp and 236 lb-ft of torque to the rear wheels through a six-speed automatic transmission. The BMW eDrive hybrid synchronous motor produces 131hp and 184 lb-ft of torque to the front wheels through a two-stage automatic transmission. Together the total output equates to 362hp and 420 lb-ft of torque. For those interested in charge time, it will take 3.5 hours for a full charge if connected to a 110v power outlet but if you spring for the BMW i Charging Station the process takes only 1.5 hours. Along with torque distribution designed to optimize efficiency is a five-mode Driving Experience Control switch. Comfort mode balances performance and fuel efficiency with unrestricted access to all features. Eco Pro mode promotes optimal mpg and lowers the electrical draw of features like AC, seat heating and heated mirrors. According to BMW, in an everyday driving scenario on a full charge and tank of gas the i8 can travel over 310 miles in Comfort mode. The lithium-ion battery pack (liquid-cooled), combustion engine, electric motor, power electronics, chassis components, and structural components all fall within the Drive module. Helping improve performance and stability, the i8 has a low center of gravity of under 18in - lower than any other current BMW model - combined with near 50:50 weight distribution.

DRIVE TRAIN.

1.  The BMW i8 embodies a revolutionary, future-focused interpretation of driving pleasure for which BMW is renowned. It was purpose-designed as a plug-in-hybrid sports car offering agile performance, near 50:50 weight distribution and outstanding efficiency. An exceptionally lightweight and aerodynamically optimised body – including a passenger cell made from CFRP – plus advanced BMW eDrive drive system technology, a compact, highly turbocharged 1.5-litre petrol engine with BMW TwinPower Turbo technology and intelligent energy management all come together to create an overall concept that represents a new landmark in the EfficientDynamics development strategy.
2. first BMW production model to be powered by a three-cylinder petrol engine. This highly turbocharged unit is equipped with latest-generation BMW TwinPower Turbo technology with high-precision injectors positioned between the valves, along with VALVETRONIC.  The low roll torque is further reduced by a balancer shaft, while a multi-stage damper integrated in the automatic transmission ensures very smooth and refined running at low rpm. This three-cylinder combustion engine in the BMW i8 develops 231hp and drives the rear wheels, while a maximum torque of 320Nm is available from 3,700rpm.
3. The car’s second power source is a 96 kW/131hp hybrid synchronous electric motor which sends its power to the front axle.  The motor develops 250Nm torque from a standstill.  As well as providing a power boost to assist the petrol engine during acceleration, the electric motor can also power the vehicle by itself with a range in everyday driving of up to 22 miles and a top speed of 75mph on electric power alone, drawing its energy from a lithium-ion battery.  Developed by BMW Group, the high-voltage battery has a liquid cooling system, offers a maximum usable capacity of five kilowatt hours and can be recharged from a conventional household power socket, at a BMW i Wallbox or at a public charging station.
4. The rear wheels of the BMW i8 are driven by the petrol engine via a six-speed automatic transmission, while the front wheels receive their power from the electric motor via a two-stage automatic transmission. Combined maximum output of 362hp and combined peak torque of 570Nm provide all-wheel-drive performance which is as dynamic as it is efficient.

ADVANTAGES OF i8 ENGINES.

• One of the basic advantage of the BMW i8 car is its extraordinary design combined with a similar fuel efficiency almost akin to that of a small car.
• Can use either petrol or electric engine or using both motor.
• On entering the corner, the power split is biased towards the rear wheels to improve turning precision. For more vigorous acceleration out of the corner, the powertrain controller returns to the default split as soon as the steering angle becomes smaller again.

VALVETRONIC

This highly advanced technology replaces the conventional throttle butterfly with a electrical mechanism that controls the amount of lift of the individual intake valves on each cylinder. Your engine is able to breathe freely, delivering better performance while using less fuel.

The performance of the engine is more efficient and immediate, thanks to the elimination of the pumping losses and air-flow disturbance caused by a conventional throttle butterfly. Instead, air can flow through the intake manifold freely, and Valvetronic precisely regulates the quantity of air entering the cylinders.

Valvetronic uses a stepper motor to control a secondary eccentric shaft fitted with a series of intermediate rocker arms, which in turn control the degree of valve lift. The throttle butterfly is no longer needed as a means of controlling the air supply - though for safety reasons it is still fitted as an emergency back-up.

By optimising the fuel/air mix process, Valvetronic produces fuel savings of up to 10 percent (based on the ECE driving cycle). In addition, Valvetronic improves cold start behaviour, lowers exhaust emissions and provides smoother, more immediate power.

      Additional Links, feel free to check them out!      ツ

• Valvetronic
• US auto parts (Valvetronic) 
• BMW forums (Valvetronic)
• http://www.europeancarweb.com/news/1309_bmw_i8_coupe_specs_announced/ 
• http://en.wikipedia.org/wiki/BMW_i8
• https://www.press.bmwgroup.com/pressclub/p/gb/pressDetail.html?title=the-new-bmw-i8-%E2%80%93-the-future-supercar-now&outputChannelId=8&id=T0145575EN_GB&left_menu_item=node__6728