Autoweb.com.au
Report on the Alfa Romeo 156 Sportwagen
http://autoweb.drive.com.au/cms/A_55360/newsarticle.html
The Alfa Romeo JTS Engine: Delivering the Lean Burn Promise
It has long been known that lean burn technology and direct fuel injection held out the promise of better fuel economy, lower emissions and more power and torque for a given engine capacity. However, until now, the drawbacks of poor high engine speed performance, the requirement for low-sulphur fuel and the requirement for extensive emission equipment to cut the nitrogen oxide emissions (which lead to nitric acid rain) have proven substantial barriers to putting this technology in production.
But for Alfa Romeo, renown for its highly efficient engines - the 2.0 litre Twin Spark engine, with 114 kW was, until the arrival of the JTS, one of the most efficient and highest specific output engines in the world - direct injection and lean burn technology offers a significant step up in efficiency, emissions and performance.
That Alfa Romeo has met its targets is clearly illustrated by the figures. The new JTS engine has exactly the same capacity as the Twin Spark engine it replaces, yet power is up from 114 kW to 121 kW; torque rises from 187 Nm to a remarkable 206 Nm. The new engine meets the ultra tough Euro 4 emission standards and yet, despite the performance gains, fuel consumption stays virtually the same. Of particular importance to Australia, there is no requirement for low sulphur fuel. It also delivers smooth and potent performance to the top of its rev-range.
On the road this translates into providing the Alfa 156 Sportwagon with more tractable performance in all the gears, a smoother torque and power curve delivers more refined performance and, in raw figures, top speed rises from 216 to 220 kmh and the zero to 100 kmh time is cut from 8.6 to 8.2 seconds.
So how has Alfa Romeo managed to achieve what other car makers have been trying to do for decades?
Alfa Romeo's answer is as simple as it is sophisticated. At low engine speeds, which the engine operates for the majority of the time, it operates as a lean burn engine, while at higher engine speeds it progressively switches to a normal fuel air mixture to provide the top end performance so beloved by Alfa Romeo drivers. The later is both enhanced and enabled by the use of direct fuel injection, with the fuel pumped directly into the cylinder head around the sparkplug, boosting volumetric efficiency and performance.
With regard to emissions, the combination of the direct injection and lean burn only at lower engine speeds means that Nox emissions are similar to normal engines. The large Nox catalyst converters that are typically needed and which reduce performance with high back pressures are not required. The absence of these catalysts also means that JTS owners do not have to worry about high sulphur content fuel.
In all, the Alfa Romeo JTS engine is a technical tour de force and is a worthy successor to the array of advanced, high performance engines on which Alfa Romeo has built its reputation.
http://autoweb.drive.com.au/cms/A_55360/newsarticle.html
The Alfa Romeo JTS Engine: Delivering the Lean Burn Promise
It has long been known that lean burn technology and direct fuel injection held out the promise of better fuel economy, lower emissions and more power and torque for a given engine capacity. However, until now, the drawbacks of poor high engine speed performance, the requirement for low-sulphur fuel and the requirement for extensive emission equipment to cut the nitrogen oxide emissions (which lead to nitric acid rain) have proven substantial barriers to putting this technology in production.
But for Alfa Romeo, renown for its highly efficient engines - the 2.0 litre Twin Spark engine, with 114 kW was, until the arrival of the JTS, one of the most efficient and highest specific output engines in the world - direct injection and lean burn technology offers a significant step up in efficiency, emissions and performance.
That Alfa Romeo has met its targets is clearly illustrated by the figures. The new JTS engine has exactly the same capacity as the Twin Spark engine it replaces, yet power is up from 114 kW to 121 kW; torque rises from 187 Nm to a remarkable 206 Nm. The new engine meets the ultra tough Euro 4 emission standards and yet, despite the performance gains, fuel consumption stays virtually the same. Of particular importance to Australia, there is no requirement for low sulphur fuel. It also delivers smooth and potent performance to the top of its rev-range.
On the road this translates into providing the Alfa 156 Sportwagon with more tractable performance in all the gears, a smoother torque and power curve delivers more refined performance and, in raw figures, top speed rises from 216 to 220 kmh and the zero to 100 kmh time is cut from 8.6 to 8.2 seconds.
So how has Alfa Romeo managed to achieve what other car makers have been trying to do for decades?
Alfa Romeo's answer is as simple as it is sophisticated. At low engine speeds, which the engine operates for the majority of the time, it operates as a lean burn engine, while at higher engine speeds it progressively switches to a normal fuel air mixture to provide the top end performance so beloved by Alfa Romeo drivers. The later is both enhanced and enabled by the use of direct fuel injection, with the fuel pumped directly into the cylinder head around the sparkplug, boosting volumetric efficiency and performance.
With regard to emissions, the combination of the direct injection and lean burn only at lower engine speeds means that Nox emissions are similar to normal engines. The large Nox catalyst converters that are typically needed and which reduce performance with high back pressures are not required. The absence of these catalysts also means that JTS owners do not have to worry about high sulphur content fuel.
In all, the Alfa Romeo JTS engine is a technical tour de force and is a worthy successor to the array of advanced, high performance engines on which Alfa Romeo has built its reputation.
- specifications
- completed cars
- construction
---- construction images
---- engine review 1
---- engine review 2
- the story so far
- purchasing
THE
STUNNING 53BARCHETTA HAS BEEN CREATED TO CAPTURE THE PASSION INVOKED BY
THE ORIGINAL CLASSIC MASERATI A6GCS/53.