SEMA eNews, Vol. 9, No. 25, June 21, 2006

NEW ENGINE COMBINES TURBO AND SUPERCHARGER

Volkswagen’s new TSI 1.4L DOHC I-4 is a gasoline engine that combines turbocharging with supercharging. The “beefed-up version” of the existing 1.4L DOHC I-4 has 170 hp at 6,000 rpm and a maximum torque of 170 lb-ft between 1,750 and 4,500 rpm, according to an article written by David Scott of WardsAuto.com.

A belt-driven mechanical Root’s-type unit provides the supercharging by boosting pressure at low engine speeds. As the engine revolutions increase to about 2,400 rpm, an exhaust-driven turbocharger takes over. Charge air at 36 psi passes through the intercooler, and the supercharger then decouples from the crankshaft drive pulley via a magnetically actuated clutch while a control flap closes its channel to the inlet manifold. Basically, the two boosting components are installed in series.

When compared to the naturally aspirated version of the TSI, the advantage of the turbocharged/supercharged engine is evident. The standard TSI 1.4L available in the VW Polo is rated at 75 hp at 5,000 rpm, with a peak torque output of 93 lb-ft. In order to handle more than double the combustion pressure and more than double the power output, “engineers specified the TSI cylinder block and head to be cast in vermicular graphite iron, Volkswagen’s name for compacted graphite iron, or CGI”.

The biggest advantage of this motor is its ability to create so much horsepower and torque in a compact size. A TSI-equipped Golf in Europe has achieved 38 mpg on the highway, compared to 35 mpg in the standard Golf, and emits CO2 emissions of 178 g/km, compared to 192 g/km. Volkswagen has not yet confirmed whether the TSI will be used in North America. Some sources suggest that VW will introduce a subcompact model smaller than the Golf in the future, which will be equipped with the TSI.

Source: David Scott, “Impressive Power, Economy From VW Twin-Charged Engine," www. Wardsauto.com.

 

that's awesome.....the supercharger gives the low rpm burst of torque and then the high end is all turbo

 

sweet find very interesting.

 

i really didn't have to find it, SEMA sends me newsletters all the time

i just post for those interested