| Outstanding automotive engineering
The Alfa Brera is equipped with two JTS direct injection petrol engines with Twin Phaser technology: a 260 bhp 3.2 V6 JTS unit and a 185 bhp 2.2 JTS unit. Combined with new mechanical six-speed gearboxes, with short strokes, precise engagement and low loads, both power units were developed to respect the brief from the Alfa Romeo engineers and represent the brand's interpretation of the direct injection petrol engine, which translates into enjoyable driving and high performance for the customer. Both engines adopt the direct injection JTS (Jet Thrust Stoichiometric) combustion system, which produces brilliant engine performance. Both engines deliver the quality one expects from Alfa Romeo, having been fine tuned on the Balocco test track, while final assembly takes place in the Alfa plant in Pomigliano the JTS engines naturally meet Euro 4 limits.
The new 260 bhp 3.2 V6 JTS V6 engine
The Alfa Romeo 'cuore sportivo' really beats in the new V6 3.2 litre JTS petrol engine, which delivers 260 bhp. It represents a significant departure from Alfa's previous V6 engine, as well as its natural successor. The new JTS engine is capable of a power delivery of 260 bhp (20 bhp or 8% more than the previous 3.2 V6); peak torque of 322 Nm at 4500 rpm (+ 33 Nm, an increase of more than 11%); a specific power of 60 kW/l and specific torque of 100 Nm/l; a significant increase in torque at low speeds to improve the smooth delivery (approximately 30 Nm more than the previous 3.2 V6 engine, starting from 1500 rpm); maximum revs of 6,200 rpm; minimal maintenance (hydraulic tappets and timing gear with chain drive); low weight (aluminium cylinder head and crankcase); and Euro 4 exhaust emissions limits. With this equipment, the Alfa Brera can reach a top speed of 240 km/h and accelerate from 0 to 100 km/h in 6.8 seconds.
Main technical features
The new 6-cylinder engine fitted to the Alfa Brera continues the strategy begun with the 4-cylinder engines, and adopts the JTS (Jet Thrust Stoichiometric) direct injection system. This is an original Alfa Romeo concept that injects the fuel directly into the combustion chamber with a stoichiometric mixture optimised to enhance performance, but also guarantees low consumption and respect for the Euro 4 emissions limits.
Numerous important components have been designed from scratch and are exclusive to the Alfa Romeo V6 engine. To start with, the cylinder head is aluminium and has 4 valves per cylinder, 2 camshafts per bank with the 'Twin Phaser' continuous variable valve timing (intake and exhaust) already adopted on Alfa Romeo 4-cylinder engines and now applied on a 6-cylinder engine for the first time. Variable valve timing allows the phase angle on both cams to be varied by 50 degrees, maximising performance on one hand, because the best phase can be chosen at all engine speeds, and reducing consumption and emissions with partial loads on the other.
At the same time it is possible to optimise the volumetric efficiency of the engine over the whole operating range, exploiting the degrees of freedom offered by variable valve timing: this means a very favourable torque curve, with 90% of peak torque available from 1800 rpm (290 Nm) and maintained over a broad range (from 1800 rpm to 6250 rpm). The valves are controlled by a roller finger system, with low mechanical dissipation, and hydraulic uptake of tappet play.
Another peculiar feature is the camshaft drive system which uses a primary chain that transmits the drive to the heads via two secondary chains. Tension is provided by automatic hydraulic tensioners, which need no maintenance at all during the life of the engine.
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