Unsung heroes: Nissan March Super Turbo

For the month of March, what could be more appropriate than a car called March? Everyone must know the Nissan Micra (or March as it's named in Japan) and it's definitely not an obscure car, but I must admit to being totally unaware of this particular version and have my friend Matt to thank for telling me about it. As soon as he mentioned what was under the bonnet, something you really wouldn't expect from such a car, I knew it was worthy of inclusion in the unsung heroes series, so here's the story.

It may look like a barried up Micra but there's something very unusual under the bonnet (image: Nissan)

The Volkswagen Group may be making headlines with their twincharged TSI engine range featuring both a turbocharger and a supercharger and claiming this to be a 21st century innovation, but this technology's first use in a production car was actually three decades ago in a limited-run and largely unknown high-performance version of the Nissan March. Here in the UK the Micra has an unglamorous reputation as the car of choice for pensioners, driving instructors and pizza delivery boys, so the Super Turbo will make you look at it in a more exciting way, but sadly it was sold only on the Japanese domestic market and is virtually unheard of in Europe.

Turbocharger on one side, supercharger on the other - a rare combination (image: Nissan)

I'm sure many readers have driven a turbocharged car without giving much thought to how it works, so to understand the benefits of twincharging it is first necessary to explain the differences between turbochargers and superchargers. Without getting too technical, both are compressors that increase the pressure of the air entering the engine, resulting in better combustion and more power, but the drive method differs. The turbines in a turbocharger are driven by the exhaust gases, whereas those in a supercharger are engine-driven, usually via a belt or chain from the crankshaft. When fully operational, the turbocharger is more efficient as it is driven by the otherwise wasted exhaust gases and doesn't use any engine power, but suffers from 'turbo lag' while the exhaust gas pressure builds up enough to spin the turbines. On the other hand, the supercharger is generally less efficient as some of the extra power it produces is used to drive the compressor itself, but this means it gets up to speed immediately with no lag and provides a better response at low engine revs.

The Super Turbo badge and twin exhausts aren't just for show
(image: marchdan on RetroRides.com)

The idea behind twincharging is for each blower to compensate for the weakness of the other and provide extra power under all conditions, so the supercharger gives a boost straightaway while the turbocharger spools up, and once up to full pressure the more efficient turbocharger takes over to deliver more power at high revs. Although it has its benefits, twincharging is a rare practice due to the cost and complexity of fitting two forced induction systems and making them work together. The principle was initially adopted by Lancia for their Group B rally cars in 1985, but the March Super Turbo was its first application in an affordable volume production car. The reason for its existence is the same reason that gave birth to so many other strange and exotic performance models: homologation for motorsport. It was introduced in 1987 for use in its own one-make race series, the March Little Dynamite Cup, but to make it eligible for wider competition Nissan were required to build no less than 10,000 roadgoing examples for sale to the public, and that's exactly what they did so they could take it rallying.

The Little Dynamite Cup had a whole grid of Super Turbos (image: Nissan) 

Nissan's twincharger system is rather clever, being controlled by a magnetic clutch, and was designed to only activate under hard driving, so when pottering around town neither blower is active and it feels just like a run-of-the-mill Micra. Put your foot down though and the magic starts to happen, as the supercharger first cuts in to deliver an immediate 10psi of boost up to about 4000rpm. At that point the turbocharger is up to speed, so it takes over to give 14psi all the way to the red line and the supercharger disengages. This makes it a parallel twincharger, in which each blower is used separately, unlike the simpler and more common series arrangement used in the Volkswagen TSI, where the output from the supercharger is connected directly to the input of the turbocharger and both run together. That's a very sophisticated bit of technology to find under the bonnet of a humble Nissan Micra.

The March R was the stripped-out version, basically a road-legal racer (image: Nissan)

Very little has been written about the Super Turbo in English so information is hard to come by and its record as a competition machine is unknown. There seem to have been two different versions though. The 1989 Super Turbo was a civilised road car with a proper interior and a unique bodykit, and appears to have been the homologation special, while the earlier March R of 1988 had the same engine in a stripped-out road-legal racer featuring full-harness belts and a roll cage seemingly as a replica of the Cup cars. Its power output is impressive even by today's standards at 110bhp from just 930cc, more than double the mere 52bhp developed by the larger 987cc unit used in the basic Micra; even now 100bhp per litre is nothing to be ashamed of so to considerably exceed this 30 years ago was quite something.

R for Rally, presumably (image: Nissan)

Even in fully-trimmed roadgoing spec the car weighed in at just 770kg, giving an incredible power-to-weight ratio of around 140bhp per tonne that makes it a real little pocket rocket more than capable of embarrassing drivers of bigger cars. The Super Turbo is still the fastest production Micra ever made and its top speed is quoted as 112mph, which isn't that fast but it was all about acceleration rather than outright speed: 60 could be achieved in less than eight seconds and the power delivery was instant with no turbo lag thanks to the supercharger. A limited-slip differential went some way to controlling all that power, but even at fairly low revs the boost from the supercharger would make the front wheels spin and it was unsurprisingly prone to understeer. The all-aluminium engine was coded MA09ERT but better known as PLASMA, one of those wonderful contrived Japanese acronyms that apparently stands for 'Powerful & Economic, Light, Accurate, Silent, Mighty, Advanced'.

This must be one of very few Super Turbos in the UK. It was for sale on Retro Rides in 2009.
(image: marchdan on RetroRides.com)

All 10,000 of the Super Turbos were sold in Japan and survival rates are unknown but probably quite low due to the general Japanese dislike of old cars, although they do have a cult following. A handful made it to Europe as grey imports, and there appears to be at least one in the UK and one in Ireland. You've got to love the Japanese for their ability to extract crazy amounts of power from tiny engines, and the March Super Turbo is a particularly fascinating example with its pioneering use of a rare and exotic technology. The strange thing is that Nissan never used twincharging on any other car, and the idea seemed to die out for many years before being picked up again in the 21st century. Next time you see Volkswagen making a fuss about their innovative twincharged engines, just remember it had actually been done quietly some 30 years ago in an unassuming little Nissan Micra of all things!

The archetypal British image of the Micra, parked in a disabled space and probably owned by an OAP who really wouldn't like the Super Turbo!