[PTA SC] Audi A2 1.6 FSI @ 992kg

De OP
The application of gasoline-direct-injection technology is steadily gaining momentum in production cars, and the first Audi to receive it is the aluminum-bodied, spaceframe A2. Designated FSI (Audi says the initials do not stand for anything specific), its possible arrival in a production car was signaled in 1997 when the A12 concept was shown at the Frankfurt Motor Show with a three-cylinder direct-injection gasoline engine. Also, direct injection was used for Audi's 2001 Le Mans-winning R8 racecar.

One of the benefits the technology brings to long-distance competition cars is improved fuel consumption, and hence, fewer refueling stops. Audi cites potential fuel consumption reduction of up to 15% in production cars. The company lists the core elements of the technology as a common-rail fuel-injection system with high-pressure injection pump; a four-valve cylinder head with laterally located injector and intake port divided by a tumble plate; two-position tumble control; an external exhaust gas recirculation (EGR) system; optimized emissions treatment system with NOx-storage catalytic converter and NOx sensor; and two-line exhaust gas cooling with radiation cooler.

According to Audi, the greatest challenge apart from exhaust gas treatment was the implementation of the necessary software in the engine control unit (ECU) because of the many maps and the transitions between the operating states, calling for a computing capacity more than twice the norm. Advanced computer simulation techniques were applied to achieve a match of the 3-D maps. Injection pressures are up to 11,000 kPa (1600 psi).

Audi's new gasoline-direct-injection engine for the A2 1.6 FSI features an external exhaust gas recirculation system and a common-rail injection system with a high-pressure injection pump.

The Audi engine has a two-position tumble flap in the intake port. When open it allows air unobstructed ingress. In its second position it moves against a tumble plate shielding the lower part of the intake port to channel intake air via a controlled path into the combustion chamber. Audi claims that this feature makes two operating modes possible, which are the fundamental requirements for the versatility of the FSI principle: homogeneous- and stratified-charge operation. Depending on load status and accelerator position, the engine electronics always switch to the optimum mode without the driver noticing. The FSI engine has a 12.1:1 compression ratio.

A problem with direct-injection-gasoline technology has traditionally concerned NOx emissions, with excess air in the combustion process making it difficult to reduce NOx to nitrogen gas completely by using a conventional catalytic converter. Audi says it has used a "series of measures" to solve this problem. EGR is one of these measures, resulting in untreated NOx emissions being reduced by some 70% during stratified lean-burn operation.

The debut of the 1.6 FSI broadens Audi's A2 range to four, which includes two 1.4-L versions (one gasoline, one diesel) and a 1.2-L diesel.

Another measure is the engine being equipped with two catalytic converters, one of the regular three-way type positioned behind the manifold, and the other a NOx "storage-type" converter located beneath the floorpan and specifically developed for a direct-injection-gasoline engine. It has a barium coating with which the oxides of nitrogen combine and is controlled via mapping and temperature. When the converter is saturated, the engine's mixture is briefly made richer, raising the temperature of the slightly rich exhaust gas. The barium molecules in the converter release the oxides of nitrogen, which are then reduced to nitrogen, explains Audi. A NOx sensor is positioned at the discharge end. NOx-storage converters operate most efficiently between 250 and 500°C (482 and 932°F), therefore this range is the prerequisite for the lean-burn operation of the gasoline-direct-injection engine since NOx emissions are particularly high in this mode. To ensure that exhaust gas temperatures remain within this range, the A2's exhaust system is fitted with an exhaust gas cooler positioned ahead of the NOx-storage converter. To improve cooling efficiency particularly when exhaust gas temperatures are high, the heat sink is designed as a radiation cooler.

The A2 1.6-L FSI engine has an output of 81 kW (109 hp) at 5800 rpm and a maximum torque of 155 N•m (114 lb•ft) at 4500 rpm. Engine management is via a Bosch Motronic MED7. The engine is mated to a five-speed manual transmission. Suspension is similar to that of other A2 versions, with MacPherson struts and lower wishbones at the front, torsion beam at the rear. Performance includes 0-100 km/h (62 mph) acceleration in 9.8 s, top speed of 202 km/h (125 mph), and fuel consumption of 5.9 L/100 km (40 mpg). Unladen mass of the car is 992 kg (2187 lb). The fuel-tank capacity on all A2s has been upped from 34 to 42 L (9 to 11 gal).






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quote:

Op woensdag 3 mei 2006 11:31 schreef Hugster het volgende:
[afbeelding]

@ 992 lb-ft

Ik wilde hem net maken

[afbeelding]

992 lb-ft is 1345 Nm en dat heeft is 95 Nm te veel

%$#^%$&!*(&^%(*&!!!!!! Postbank

BoJo, Sjoewe

Hugster