Turbocharged and Supercharged
American MX-5 tuning specialist, Flyin’ Miata, has been kicking its way into the headlines with the announcement of a possible ‘twincharger’ conversion for the 2.0-litre engine in the mk4. Twincharging involves sticking both a turbocharger and a supercharger under the same bonnet.
Those of you with long memories may recall that the most famous exponent of this forced induction double-act was Lancia, which fitted both systems to its stunning 037 Group B rally car – the fact that the mid-engined monster won the 1983 WRC manufacturer’s title for Lancia rather validated the potential of the technology. More recently, Volkswagen has used twincharging on very small engines to provide decent performance combined with good economy and emissions.
Flyin’ Miata’s intention for the twincharger setup is purely performance, but there’s a way to go yet before we learn precisely how much power it might make. However, it should be north of what the company’s turbocharger conversion – supplied by British specialist, BBR – on its own achieves, which is in the region of
250bhp. The twin stumbling blocks to announcing something more definitive on the power front, according to Flyin’ Miata’s Keith Tanner, is that the car’s existing fuelling arrangements can’t keep pace with the hungry demands of the twincharger system, and that the engine’s internals are likely not strong enough and need more robust replacements.
The creation of the twincharger conversion came about by accident. Flyin’ Miata’s turbocharged RF demonstrator arrived in the workshop to have its turbo replaced by an Edelbrock supercharger. But then someone suggested leaving the turbo in place, just to see if installing a supercharger as well could be done. It could.
Forced induction duties are initially handled by the turbocharger, which feeds air through an air-to-air intercooler; the air’s then introduced to the supercharger before passing through an airto-water intercooler and into the engine. Finding room in the nose for both intercoolers was one of the key packaging challenges.
We look forward to seeing the completed machine.