turbo

[edit] 1968–1993 The modern (1968–1993) straight-6 was used in the largest Opel and Vauxhall cars from General Motors. It was displaced by the Opel-designed 54° V6 in the mid 1990s. These engines began as pushrod-operated overhead valve units with carburetors in the 1960s, gaining fuel injection and a single overhead camshaft in 1986. A special Lotus version had dual overhead camshafts and 24 valves for 1990's Lotus Omega/Carlton. [edit] 2.5 The modern Opel straight-6 line began in 1968 with the 2.5 L (2490 cc) unit used in the Opel Commodore. Still a 12-valve engine, it had a very oversquare 87.0 mm (3.4 in) bore and 69.8 mm (2.7 in) stroke. 9.5:1 compression and a single carburettor produced 117 PS (115 hp/86 kW) and 174 N·m (128 ft·lbf), while 9.0:1 compression and dual carbs produced 132 PS (130 hp/97 kW) and 186 N·m (137 ft·lbf). This same engine reappeared in 1977 in the Opel Monza, now with Bosch fuel injection producing 140 PS (138 hp/103 kW) and the same 186 N·m (137 ft·lbf). The carburetted version was still produced for the Commodore as well. An SOHC version of the 2.5 was used in the 1987 Opel Senator 2.5i. Bosch injection gave 142 PS (140 hp/104 kW) and 205 N·m (151 ft·lbf). [edit] 3.0 The 3.0 L (2969 cc) version was introduced in 1977 alongside the fuel-injected 2.5. Also fitted with Bosch LE-Jetronic injection, the 3.0 produced 181 PS (178 hp/132 kW) and 248 N·m (183 ft·lbf) in the Opel Monza GSE and Opel Senator 3.0E. Bore was up to 95.0 mm (3.7 in), but stroke remained at 69.8 mm (2.7 in). The 1986 Opel Omega 3000 GSi introduced the SOHC version of the 3.0. The injected engine produced 180 PS (177 hp/132 kW) and 240 N·m (177 ft·lbf). It was later used in the Senator and Omega 3.0i. [edit] Lotus The Lotus Omega/Carlton introduced a stroked (to 85.0 mm (3.3 in) version of the engine displacing 3615 cc. Lotus used twin Garrett T25 turbochargers and an air-to-water intercooler along with 8.2:1 compression and custom fuel injection. The turbos were arranged in parallel, each fed by and feeding three cylinders. The company reportedly experimented with a variety of forced induction schemes, including paired supercharging and turbocharging and sequential turbos, before settling on two small turbos for quick spool-up. The Lotus engine produced 382 PS (377 hp/281 kW) at 5200 rpm and 568 N·m (419 ft·lbf) at 4200 rpm. hopefully this will benefit your interests