BBR GTi Mazda MX-5 1.5 2018 first drive

For a subset of car lovers, BBR GTi will be a familiar name. Performance-chasing owners of the R53 Mini and fans of celebrated Ford rockets such as the Sierra Cosworth will likely know of the place, which now sits in the literal shadow of Mercedes’ Brackley-based Formula 1 HQ. This is an outfit best known, however, for turbocharging a car normally praised for its free-spirited naturally aspirated engine: Mazda’s purer-than-pure Mazda MX-5.

BBR sells around 100 MX-5 turbo kits a year, almost half of which end up in America though there have also been recent dispatches to customers in places as far afield as Bahrain and Taiwan. The firm’s dealings with the big-selling Japanese roadster go back to the first-generation car, and the 1.5-litre model tested here represents its latest and arguably most finessed effort yet.

Despite figures that suggest this kit comprehensively remedies the somewhat lacklustre 129bhp shove of the standard car, aside from the natty decals you’d never know it was anything other than a garden-spec 1.5-litre Mazda MX-5. We like that. Even if you stood next to it at idle, you’d still be none the wiser. 

In fact, it would only be when you attempted to keep this car’s backside in sight along a twisting B-road that the game would be up, because under the bonnet is a neatly installed Stage 1 turbocharger upgrade that yields 210bhp and 197lb ft. With a negligible six-kilogram weight penalty on top of the factory model’s 1050kg, the resulting power-to-weight ratio is roughly what you’d find in an Audi TTS Roadster.

Initially at least, the BBR’s reasonably subtle aesthetic is mirrored in the driving experience, and it’s apparent this conversion is no heavy-handed boost-fest. There’s a gentle coo from the turbocharger atop a slightly industrial four-cylinder rasp and throttle response is dulled very slightly, but otherwise the experience is some way from the tuner fanfare you might expect (BBR GTi can, however, also do that rather well). The clutch is factory-spec, the electronic aids remain unaltered, and there’s nothing inside the cabin to suggest the car has been tickled really quite vigorously.

BBR’s original intention was to develop a naturally aspirated kit for the zingy SkyActiv 1.5, but it found Mazda had developed this powertrain to such a high degree that even substantial modifications made few gains. Remapping the ECU for more power is, of course, largely fruitless unless forced induction is involved and so turbocharging it was. That brought with it not only a need to comprehensively reprogram the car’s ECU, but also complexities owning to the engine’s very high compression ratio and the vast amount of camshaft advance that gives the 1.5 its free-revving character.