More Mazda Roadster MPS Details

by Bob Hall

Another reveal at the Tokyo Motor Show was the Japanese debut of the MPS version of the Mazda Roadster (what the Miata is called in Japan). Though seen at the Frankfurt Motor Show in September, Mazda released more technical information on the Mazdaspeed-modified, 200hp/147kW version of the world's best selling two seat sports car. Unlike the turbocharged 200hp/147kW Mazda MX-5 SP announced in early October by Mazda Australia, Japan's Roadster MPS is normally-aspirated.

Core of the new model is a heavily modified version of the BP 1.8 litre four fitted to the Miata in most markets. Designated BP-VE, the MPS engine has displacement of 2.0 litres, a notable increase from the standard BP's 1839cc. Neither Mazda nor Mazdaspeed has revealed the actual displacement of the BP-VE, though word from internal sources indicates the car is the recipient of an increase in both bore and stroke. Peak power is 200hp/147kW at 7000rpm, with peak torque of 145lb-ft/196Nm generated at a peaky 6000rpm.

The BP-VE has a dedicated throttle body for each intake port, and Mazda's using a set of high-lift cams. Mazda reports a piston speed of 19.8 metre/second for the BP-VE, an interesting figure though of questionable value without a similar rating from the standard BP. The engine works through the six-speed manual transmission available with the normal 1.8litre BP-powered car.

Mazdaspeed and Mazda's internal chassis development people have made some notable modifications to the chassis and braking system of the MPS. Height adjustable mono-tube shock absorbers and coil springs replace the more prosaic items fitted to other Mazda Roadsters/Miatas/MX-5s (including the turbocharged MX-5 SP). Lower suspension mounting points have been reinforced with an aluminum ladder underbody reinforcement to improve chassis rigidity.

The Roadster MPS rides on 7-inch wide 17-inch alloys shod with 215/40 17 tires (Michelin Pilots on the display car at Tokyo). Brake diameter for the MPS is 12.4in/314mm at both the front and rear, though the front discs are ventilated while the rears are solid. With the different wheel and tire package the front track is increased by 2.0in/50mm with the rear track 2.4in/60mm wider than the car with the 16in wheel and tire package. Front and rear fenders of the MPS have been flared to accommodate the car's meaner rubber. The front and rear bumper skins are also different to the standard NB8B and set of quad circular lamps replace the composite headlamps units of the standard car.

Interior modifications are pretty minor and conservative, with buckskin and Alcantara (a very good simulated suede) covered resculptured buckets seats and a few metallic-finish interior components scattered about. Thankfully fake carbon fiber is nowhere to be seen.

The Roadster MPS is a limited production model (with a rumored production figure 200 cars) for the Japanese market only and won't be available in export although some of the components may be offered by Mazdaspeed later in the year. Prices haven't been announced, but wags in Japan have been mooting figures in the 3,500,000 to 4,500,000 Yen range, which equates to an approximate range of US$28,525 to US$36,700. Ouch!

Bob Hall