It is a familiar trick that buyers of exotic sports cars seem happy to accept: take your already fast and expensive machine, simplify the interior, improve the aerodynamics, stiffen the suspension and add a little more power.

You can then sell the result as a new “racing version”, describe it in vague but enticing language such as “more focused”, and finally give a significant boost to the price tag.

The Maserati GranSport apparently fits this pattern, established by the Ferrari 360 Challenge Stradale and Porsche 911 GT3. There is, after all, a Maserati Trofeo series for gentleman racers (and gentlewomen, including Driving contributor Jodie Kidd). But Maserati is emphatic: the £66,600 GranSport —— £9,350 more than the Coupé on which it is based — is not a road-legal race car.

Ironically, it was my session driving it on a race circuit — Varano de’Melegari, near Parma in northern Italy — that proved the point. The GranSport was fast in a straight line, stopped well and swept through the bends with confidence, but it lacked the sharpness of a proper track car.

Out on the roads, however, twisting through the gentle hills of Lombardy, this car felt just right: tauter than a regular Maserati Coupé but still reasonably comfortable over bumps, more responsive but not overly aggressive.

In short this is the best yet of this generation of Maseratis. The GranSport is in the same price range and has the same performance as the latest Porsche 911 Carrera S. You could say it was designed for people who don’t like Porsches, a more dramatic and exciting Italian alternative to the efficient, reliable and now perfected German sports car.

The starting point for the GranSport is the Coupé Cambiocorsa. That name means “racing change” and refers to the semi-automatic six-speed gearbox used in both cars and operated, Formula One-style, by paddles behind the steering wheel. There is no clutch pedal. It is the same system as used by Ferrari — which owns Maserati — in the F1 variants of the 360 Modena and the new F430.

The GranSport’s engine is built with specially selected components to finer tolerances than the standard Coupé Cambiocorsa. The result is a power increase of 10bhp to 400bhp. And, taking a tip from Ferrari, the exhaust system has a valve to reduce back pressure and make a gloriously rich sound when it starts up and, later, when you press the “sport” button on the dashboard.

Thanks to improvements in its computer control, gearchanges are 35% faster than the Coupé’s but still not as brutal as the Ferrari’s. The GranSport has a higher top gear ratio which, according to Maserati, enables a 180mph maximum speed. The 0-62mph time of 4.85sec is a 0.05sec improvement on the standard car’s. Of course, you don’t notice that.

The keen driver is more likely to appreciate the difference made by lowering the car, fitting 19in wheels with special Pirelli tyres, and the Sky Hook active dampers that act 10 times faster than conventional adaptive damper systems.

Maserati is proud of the aerodynamic improvements that have accompanied styling changes to give the GranSport a lower look and a more muscular stance: a larger chrome mesh grille and under-bumper air intakes, and sill extensions below the doors that are almost big enough to act as running boards. They ought to have a “no step” label, as on aircraft wings.

Despite its extra appendages, I think the GranSport looks good. It scores over its coupé rivals by having four usable seats. The interior decor tries very hard to be modern-sporty instead of leather-bound traditional like the standard Coupé.

Perhaps it tries too hard. The neat carbon fibre moulding forming a narrow centre console is fine but I am not so sure about the soft trim material. Frank Stephenson, the Ferrari and Maserati design chief, found some metallic-looking fabric at an Italian fashion show, in silver, silver and black, and pale blue, that was developed for high-tech sports clothing. It is applied all over the GranSport’s cockpit — across the fascia, on the door panels, the centres of the excellently shaped sports seats, and even the headlining. In silver, arguably the best of the three options, climbing into the car is like getting into a fireman’s protective suit.

The GranSport retains the electric seat adjustment and all the other features and equipment of the Coupé, save for the full-colour display screen that can’t fit in the slimmed-down fascia centre. This does, however, position close to hand the important driving controls, such as the engine starter, the sport button that alters the damper characteristics, the speed of the gearchange, accelerator response and the intervention of stability controls, and the switch that turns off the traction control.

There is no need to delete this electronic helper. With sport mode selected the traction control has a high threshold of operation that allows the enthusiastic driver to slide the tail a little before it safely reins him in. It is a good compromise for road use and that is what the Maserati GranSport is for. This is not a road-legal race car — and it is all the better for that.