The History and Future of Forced Induction Motorcycles

In just a few weeks, the first forced induction motorcycle to be produced since 1985, the Kawasaki Ninja H2, will hit showrooms – a hiatus of 30 years for a technology used in not only performance cars but increasingly in family sedans and hatchbacks. So why have there been so few forced induction motorcycles and is the Ninja H2R just a gimmick or a sign of things to come? Let’s take a look at the past and possible future of forced induction motorcycles.

The Past

While Kawasaki sold a turbocharged Z1R-TC made by the Turbo Cycle Corporation in the late 70’s, the first true production forced induction motorcycle was released by Honda.

The Honda CX500 Turbo was released in 1982 and based upon the technologically advanced (at the time) CX500. In addition to its turbocharger, it also featured computer controlled fuel injection, ignition and turbo control. The base CX500 featured the first V-twin ever built by Honda and it became the perfect base for its turbocharging experiment. According to Motorcycle Classics, air was routed from the front of the CX through an oiled foam air filter and then into the compressor part of the turbocharger. From the turbo mounted in front of the engine, air traveled to a plastic box (called a surge tank), and then through reed valves and intake tubes into the cylinder head. Fuel passed through a fuel filter before being pushed under pressure by an electric fuel pump, where it was fed to fuel injectors that released a precisely calibrated flow of fuel to the intake tubes.

Reactions to the CX500 Turbo was mixed. Most journalists either loved or loathed the turbo sensation. Detractors stated that the bike became too hard to control when the boost came on, especially in the corners. The following year Honda bumped the capacity of the engine up to 674cc and increased the compression ratio to 7.2:1 which increased power to 97 hp, but it was short lived. The turbocharged model was discontinued by the end of the year.

Soon following Honda’s release of the CX500 Turbo was Yamaha’s response – the XJ650LJ Seca which had the distinction of featuring in the Bond film Never Say Never Again. It featured a four stroke transverse four cylinder turbocharged DOHC, 2 valves per cylinder engine with a capacity of 653 cc. Unlike the Honda CX500 turbo, it was air cooled and pumped out 90 hp at 9,000 rpm. It was also far more low-tech than the Honda – something that many actually preferred – using carburetors instead of electronic fuel injection.

The Yamaha XJ605LJ Seca Turbo was also preferred when it came to riding in comparison to the Honda. The transition from off-boost to on-boost power was less sudden than the CX, making it easier to ride over mountain roads. That said, the same criticism that that was leveled at the Honda was also made of the Yamaha – turbo lag. The reduced lag and extra low-end and mid-range power made the Seca easier to ride hard than the Honda, but for sport use both required far more concentration and skill than for any good non-turbo bike

Suzuki was the third of the Japanese giants to enter the turbo game, with the brand new XN85. Specifications wise it was quite similar to Yamaha’s offering – same engine configuration, similar weight and a capacity only 20 cc more than the XJ650LJ. However, unlike the offerings from Honda and Yamaha, the Suzuki XN85 was developed from the ground up exclusively as a turbo bike, rather than modified to fit an existing platform. It featured the first 16-inch front wheel on a production bike, low clip-on handlebars, rearsets and a single shock rear suspension – a rarity for the times.

The bike was a commercial failure however. Only 1,153 examples were actually produced and it was discontinued after less than a year.

Last to the party and last to offer a turbocharged motorcycle for sale was Kawasaki with their E1 and E2 GPz750 Turbo bikes. As far as performance went, the GPz750 was the king of the turbocharged bikes thanks to its larger displacement – 112 hp @ 9,000 rpm and a massive 99.1 nm @ 6,500 rpm. Upon its release it was claimed to be the fastest production bike in the world. In addition to having the best performance figures, it was generally regarded as the best example of a turbo motorcycle. Lag was down and the turbocharger actually did what it was intended for – to make it quicker than a comparable normally aspirated machine. Commercially it did well too – being sold for three years in comparison to the other makes one year stint.

But economics of production and cost of ownership meant that even Kawasaki’s machine was eventually withdrawn and we wouldn’t see another forced induction motorcycle until the announcement of the Kawasaki Ninja H2 and H2R last year.

The Present

The year is 2014 – 32 years after Honda released the CX500 Turbo and Kawasaki announces the Kawasaki Ninja H2, the world’s first production supercharged motorcycle. The Ninja H2R would be for the track only.

We’ve talked in great length about both the Ninja H2 and H2R and while we’re extremely impressed by the specifications of the H2R, we’re a little less enthused about the road legal H2 which suffers from excessive weight. The H2R makes nearly 300 hp from one litre of engine capacity and it does so by forcing far more air into the system than a normally aspirated engine can. And that’s probably the reason why the H2 is so heavily detuned – that process will create a lot of heat. That’s not good for longevity and ironically, heat will actually decrease air density and therefore reduce power. Kawasaki have innovated a whole host of new technologies to overcome these issues, but that’s not cheap. Nor is tested in the real world and Kawasaki probably don’t want a lot of money on warranty claims eating into their profits.

But Kawasaki aren’t alone in looking at supercharging. Patents were discovered late last year showing Honda is seriously looking at a supercharged bike based on the NC750. The Honda NC750S and NC750X are unique motorcycles as they stand, with huge amounts of luggage space located where the fuel tank usually sits. This makes it an ideal candidate for forced induction as it provides an easy solution to placing a supercharger, related plumbing and an intercooler.

Then we have Suzuki and their Recursion concept which if the rumors are correct is heading into production this year as the Katana. Unlike Kawasaki and Honda though, the Suzuki Recursion makes use of a turbocharger. If and how Suzuki has overcome the issue of turbo lag remains to be seen.

So why after three decades of absence is forced induction making a comeback? The reason for it’s renaissance is actually quite boring but very important – the environment.

Yes, forced induction, whether it be provided by either a turbocharger or supercharger gives an increase in performance. But increasing performance isn’t really necessary for most motorcycles today. Just take a look at the specifications for the latest normally aspirated superbikes like the 1299 Panigale and Yamaha R1 and you can quickly see that a turbocharger or supercharger would just add unnecessary weight, complexity and cost to the machines for probably little gain. Where they do improve things dramatically is in emissions.

And that’s going to become increasingly important. It’s expected that by 2017, the European Union will require all motorcycle manufacturers to quote C02 emissions for their bikes which will lead to tax implications. Governments will continue to pressure vehicle manufacturers to lower their emissions which contribute a sizable percentage to most western nations overall carbon emission figures.

So how much can forced induction reduce emissions? Quite a lot actually.

The Ninja H2 has the exact same output as the current Kawasaki ZX-10R. But the H2’s carbon monoxide emissions are 1g/km compared to 3g/km for the ZX-10R – a reduction of 66 per cent.  Similarly, the hydrocarbon emissions of the H2 compared to the ZX-10R reduce from 0.3g/km to 0.2g/km – 33 per cent down. Just imagine the reductions when the technology becomes more mature.

Like it or not, motorcycle manufacturers ignoring both emissions and fuel consumption of their machines is coming to an end which means this time, forced induction is likely to not be a small flash in the pan but part of the ongoing motorcycle landscape – just like electric bikes. And for that, we’re more than happy as the more choice available to consumers, the more riders we’ll get on our roads.

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