{"id":25876,"date":"2022-07-01T00:04:18","date_gmt":"2022-07-01T04:04:18","guid":{"rendered":"https:\/\/autosector.com\/?p=25876"},"modified":"2022-07-01T00:04:18","modified_gmt":"2022-07-01T04:04:18","slug":"1136347_bmw-secretly-made-a-convertible-e34-m5-and-z3-roadster-powered-by-a-v-12","status":"publish","type":"post","link":"http:\/\/autosector.com\/?p=25876","title":{"rendered":"BMW secretly made a convertible E34 M5 and Z3 Roadster powered by a V-12"},"content":{"rendered":"

To celebrate 50 years of the M division, BMW has been showing off once-secret prototypes in a series of videos, but the two shown in the latest video released Wednesday are among the most unusual yet. Once upon a time, BMW built an E34 M5 convertible and a Z3 M Roadster prototypes with V-12 engines. Both cars are now part of an M 50th anniversary exhibit at the BMW Museum.<\/p>\n

It’s unclear why BMW M built a convertible version of a four-door sedan, but it did a thorough job. With no roof pillars to attach the seatbelts to, engineers relocated them to the seats themselves. The car’s top mechanism was also designed to preserve trunk space.<\/p>\n

\"BMW<\/p>\n

BMW M’s mysterious V-12 powered Z3 roadster, as posted to Facebook <\/p>\n<\/div>\n

The E34 M5 was powered by a 3.8-liter inline-6, which sent 340 hp and 295 lb-ft of torque to the rear wheels through a 6-speed manual transmission. An open-air experience of that powertrain does sound appealing. This wasn’t the only oddball E34 BMW’s skunkworks built; it also installed the 6.1-liter V-12 from a McLaren F1 in an E34 M5 wagon<\/a>.<\/p>\n

In comparison, the V-12 Z3 M Roadster seems almost conventional. The prototype first broke cover in 2012<\/a>, and is powered by what is likely an M73 engine; the 5.4-liter V-12 was used in the 7 Series when the Z3 was in production. It produces 321 hp, a big step up from the stock M Roadster’s 240 hp.<\/p>\n

Fitting the V-12 into the Z3’s engine bay was easier than it might seem. While the car itself is tiny, the engine is roughly the same length as the stock M Roadster’s inline-6. It’s just that there are two banks of cylinders instead of one. The heavier V-12 likely affected the car’s weight distribution as well.\u00a0<\/p>\n