Posted in Industry News
Submitted by Bill Smith on Thu, 15/09/2011 - 10:30
Alfa Romeo, has just introduced two brand new Euro 5-compliant engines for the Alfa 159 range - the 1750 TBi and the 2.0 JTDM. Both theAlfa Brera and Alfa Spider will benefit from these powerplants later in the year.
These two new high technology petrol and diesel engines will complement existing petrol and diesel units in the 159 range and introduce a combination of increased torque and power with lower emissions and greater fuel efficiency.
1750i 200 BHP TURBO PETROL ENGINE
The new Alfa Romeo 159 1750 TBi embodies a long heritage of motoring excellence, taking its name from its successful saloon ancestor, the Alfa 1750 Berlina. Alfa Romeo’s new, lightweight, variable valve timing, direct injection turbocharged engine develops an impressive 200 bhp along with 320 Nm of torque to bring new levels of drivability to the Alfa 159 range.
Perfectly complementing the current engine line-up, the new 16-valve, twin overhead camshaft 1742 cc petrol unit brings keen fuel efficiency to Alfa 159 Saloon and Sportwagon versions, along with lower CO2 emissions, down to 189 g/km – resulting in a six-band drop in company car BIK taxation compared to the older 2.2 JTS engine.
Significantly, through a process known as ‘scavenging’, the maximum torque of Alfa Romeo’s new petrol engine is achieved at just 1400 rpm – a little more than tickover speed – with maximum power reached between 4750 and 5500 rpm.
From a standstill, the 1750 TBi Alfa 159 Saloon can reach the 0 - 62 mph benchmark in 7.7 seconds, before toppinout at 147 mph. However it is the flexibility of the
From a standstill, the 1750 TBi Alfa 159 Saloon can reach the 0 - 62 mph benchmark in 7.7 seconds, before topping out at 147 mph. However it is the flexibility of the in-gear acceleration that sets the engine apart from its competitors; with 25 - 62 mph in fifth gear achievable in 11.5 seconds and 37 – 62 mph in sixth gear reached in just 8.9 seconds – this translates, in real world driving, to a more sporting driver experience consistent with a ‘flat’ torque curve and a constant delivery of power – perfect for confident overtaking and long distance driving.
In addition, the 1750 TBi version includes a mileage extension to 21,000 miles between routine maintenance intervals.
2.0 JTDM 170 BHP DIESEL ENGINE
Given that Alfa Romeo introduced common rail diesel technology more than 10 years ago on the Alfa 156, it should come as little surprise that it has now developed a new diesel unit that brings higher power and torque values, yet, at the same time, increases fuel efficiency and lowers CO2 emissions.
Alfa’s new 2.0 JTDM powerplant develops 170 bhp available at just 4,000 rpm, and its advanced multijet technology means that this new 2.0 JTDM unit delivers its maximum torque of 360 Nm between just 1750 rpm and 2500 rpm.
Significantly, the new 2.0 JTDM powered Alfa 159 covers the 0 – 62 mph sprint in just 8.8 seconds - less than one second off the pace of the more powerful 2.4 JTDM engine, on its way to a top speed of 136 mph.
CO2 emissions have been reduced to just 142 g/km.
NEW TRIM LEVELS FOR ALFA 159 RANGE
To coincide with the launch of these new engines, Alfa Romeo has introduced a new range structure which now features five trim levels – Turismo, Turismo Sport, Elegante, Lusso and TI.
First of the two new trim levels, Turismo Sport offers drivers sporty upgrades including 17” sport alloy wheels, Blue&Me, sports seat cloth, sports leather steering wheel with remote audio controls and gear knob, and sports dials.
The new Elegante trim adds additional style to the already highly specified Turismo equipment, including rear parking sensors, visibility pack and luxury Alfatex® interior.
Each high specification trim level brings added choice in terms of comfort, refinement, technology and aesthetics.
UNDER THE BONNET – TECHNOLOGY IN ACTION
1750 TBi 200BHP PETROL ENGINE
The enhanced performance of this continuously variable valve timing engine is the result of applying ‘scavenging technology’, maximising torque at very low engine speeds.
This is achieved by monitoring and optimising engine parameters such as fuel measurement, injection timing and spark advance. Managed by a new ECU, it is possible to define the angle and times of valve overlap in order to generate airflow from the inlet manifold to the exhaust manifold and therefore activate the turbocharger very quickly.
This new process allows for maximum exploitation of the turbocharger compared to conventional turbocharged petrol engines.
The results are maximum torque at just 1500 rpm – 70% greater than that of a conventional turbo engine – and throttle response times slashed by half.
Direct injection with an advanced double-injection strategy is essential to reduce emissions. Allowing direct control of fuel metering during the scavenging process, it is possible to prevent unburnt fuel ending up in the exhaust, which affects the catalytic converter. The secondary injection system has a new high-pressure pump and new 7-aperture injectors which guarantee perfect vaporisation.
This allows excellent performance to be achieved even in the presence of relatively high compression, and provides low consumption at cruising speeds.
Dual variable valve timing (VVT)
The two continuous phase variators on both inlet and exhaust camshafts optimise the valve timing at all speeds, minimizing consumption and emissions. In addition, by coupling the two variators to the turbocharger, the ‘scavenging’ strategy is accurately controlled.
In response to a sudden torque request from the driver, it is therefore possible to significantly accelerate engine response, even from low RPM.
This engine incorporates a new generation KKK fixed geometry turbocharger connected to an innovative pulse converter-type exhaust manifold which optimises the use of exhaust pressure waves to increment driving torque at low speeds. Both manifold and turbine are made of microcast steel so that they can withstand very high working temperatures (up to a maximum of 1020 °C). This is important for a reduction in fuel consumption while operating at medium/high speed.
Thermal fluid dynamics
The inlet ports have been designed using new technology allowing the optimal level of turbulence to be created. This results in the correct mixing of air and fuel. The combustion chambers have also been optimised by using ‘squish’ areas, minimising the surface-to-volume ratio and therefore benefitting combustion efficiency.
The entire engine has been designed to reduce losses through friction. Pistons have ‘flexible’ rings to limit tangential load and advanced materials have been used to reduce wear. In addition, the aluminium alloy cylinder head design incorporates roller rocker arms that help reduce losses through sliding contact by up to 65 % at 2000 rpm, compared to traditional cylinder heads with hydraulic tappets.
An optimised crankshaft design based on long connecting rods but a comparatively short stroke, has cut to a minimum the high speed vibration normally associated with four-cylinder engines, obviating the need for balancer shafts.
A new engine management system combined with a scavenging strategy has achieved new ‘benchmark’ levels for engine performance.
The specific torque achieved, (185 Nm per litre) is among the highest for modern petrol engines. With 320 Nm of torque available, the power unit offers significant benefits to the driver, including excellent pick-up performance, resulting in fewer gear changes.
As a result of dual injection and high injection pressure, the engine’s emissions values meet the Euro 5 limit with a relatively small catalytic converter and consequent positive effects on performance. With the production of 189 g/km of CO2 the new Alfa 1750 TBi engine sits in VED Band J.
UNDER THE BONNET – TECHNOLOGY IN ACTION
2.0 LITRE 170 BHP DIESEL ENGINE
Alfa’s new 170 bhp 2.0 JTDM diesel engine is an evolution of the hugely successful 1.9 JTDM and delivers clear and measurable benefits to the driver and the environment.
Increased torque and power make the driving experience more relaxed and responsive, while CO2 emissions have been reduced to as low as 136 g/km (on the combined cycle), meeting the Euro 5 standard and placing the model in VED Band E.
Performance is boosted from 150 to 170 bhp by increasing the displacement from 1910 to 1956 cc – achieved through extending the size of the bore from 82 mm to 83 mm - and the use of a new variable geometry turbo.
At the same time, fuel economy has been improved by friction optimisation, and a lowered compression ratio (16.5:1) results in a significant decrease in NOx emissions. Low viscosity oil and new calibrations made possible by using a close-coupled diesel particulate filter and an evolved exhaust gas recirculation system all play their part.
The result is low CO2 emissions in line with the most stringent European benchmarks.
Adding to the driver appeal of the new 170 bhp 2.0 JTDM version, routine maintenance intervals have been extended to 21,000 miles.