With the Rover V8 bored out to 3.9 litres and expertly fiddled with by racer Andy Rouse to extract serious horsepower, TVR’s wedge really staked its claim as a performance car. To prevent it being too much of a handful, the rear axle received a Torsen limited-slip diff, ducts were added for brake cooling, and the aerodynamics were tweaked to keep the wheels in better touch with the tarmac. The result was raved about in the press, but 390SE sales were restricted by it being more expensive than a Lotus Esprit, without the heritage. All models were convertibles.
info from Octane