TURBOS. My Porsche GT2 had 670 horse out of it 3.6L with very minor modifications on the factory engine. The GTR is of course a twin turbo motor also and the 4.2 R8 is normally aspirated. If you modify a 4.2L with a twin turbo kit (it needs internal engine mods for this kind of power) 700-800 horse maybe lots more should be possible.
3.0 Liter V6 Engine. Among top car manufacturers, Audi is surely hell-bent on setting a new standard for engines. The 3.0-liter engine is considered one of the best engines so far because of 325 lb-ft of torque at 2900 rpm and 333 horsepower at 5500 Rpm. Luxury cars with V8 engines are not in high demand these days. The Audi A6 (C5) 4.2 V8 Quattro has a V 8, Petrol engine with 4172 cm3 / 254.6 cu-in capacity. How many horsepower (hp) does a 1999 Audi A6 (C5) 4.2 V8 Quattro have? The 1999 Audi A6 (C5) 4.2 V8 Quattro has 300 PS / 296 bhp / 221 kW. dPiG.