JOHNNY MAC SUZUKI HAYABUSA
Since my last (first) instalment of my time with the Hayabusa, it’s been pretty full-on for me, with, among other things, the small matter of Ultimate Sportsbike that basically means two to three weeks of doing nothing else. I also organise a charity motorbike ride called The Longest Day Challenge that gets people to ride £300 motorbikes from Lands’ End to John O’Groats without using motorways on the longest day of the year to raise money for Cancer Research UK. It’s a fair undertaking, organising everything for this year’s 34 riders, and takes a good chunk of my time – all of which is a way of getting my excuses in for not actually having done anything to my Hayabusa in the last month.
However, I have been riding it… a lot. I’ve been going backward and forward to the Bathams Racing workshop in Dudley as the season approaches. As well as Fast Bikes, I also work for them and occasionally need to go to the workshop to help with a lot of the admin and PR. I’ve also been using the Hayabusa to go to the various pre-season tests they’ve been to, all of which has given me plenty of time in the saddle to get to know the ‘Busa, what I like about it and what I don’t.
Annoyingly, I can’t make it to Dudley and back home on the same tank of fuel (a 170-mile round trip). This should be possible on a bike with ideas of being a continent crusher... alas, it can only just about make it from the East Midlands to the West Midlands on a tank. To be fair, it’s not the end of the world, because the Hayabusa’s riding position, in particular the seat-tofootpeg distance, is excruciating after just 45 minutes. It’s so cramped. For the life of me I can’t understand why, having gone to all the trouble to get the engine through Euro5, and redesign the whole bodywork, and design a bespoke ride by wire system on the bike, that nobody thought to address something that to anyone over 5ft 2in tall would know isn’t even close to being right.
For a bike that’s supposed to be able to dispatch long distances with ease, it just doesn’t make sense. I’d happily swap the Hayabusa for a GSX-R. The prospect of riding it to the Knockhill round of BSB to work for Bathams Racing gives me nightmares.
The range issue is down to the adaptation of the motor and fuel injection for Euro5. The fuel tank is smaller to make way for the new airbox and throttle bodies, so range is already reduced. Then there is the reduced valve overlap, which a lot of manufacturers have had to do to get cleaner emissions.
In short, one of the ways engine designers get the most air/fuel into the combustion chamber is to time the exhaust valves to be open at the same time as the intake valves. This accelerates the intake charge, which means more gets in before the valves shut and it gets burned, which means more power. Inevitably some unburned air/fuel passes through unburned and into the exhaust, which basically ruins the emissions.
Instead of using valve overlap as a way of getting the most air/fuel into the combustion chamber, manufactures are now moving to greater valve lift, i.e., opening the valves higher with lumpier cams. To do this, stiffer valve springs
are fitted to the Gen3 Hayabusas valves to get them shut in time. Downstream the exhaust is now packed full of catalytic converters to clean up the gasses that do get burned. The result is that, thanks to having less fuel/air to burn, then a bunged-up exhaust system, not only does the latest Hayabusa make a touch less power than the previous one in the name of saving the planet, but due to having to work so hard to make that power it has… wait for it… worse fuel consumption. So, it’s cleaner but uses more fuel to be cleaner. Oh, the irony!
In theory, what the ‘Busa needs is a catalytic-free exhaust system and a re-map to get better tank range… and more power. Since it’s a Suzuki, it will have to be Yoshimura. I don’t make the rules up but Suzuki and Yoshimura go together like salt and vinegar, or fish and chips. As for the riding position, I’m going to do some digging on a taller seat or seat gel, anything to raise it, and some adjustable rearsets with a view to lowering the footpegs to get some distance between my feet and arse.
Otherwise, apart from the short tank range – which, in some ways, is actually a blessing due to the cramped riding position – I’m finding the Hayabusa to be a sound travelling partner. The engine is the star of the show, mostly due to its flexibility, so I’m sure that an aftermarket exhaust will not only make it more powerful and in theory more economical, it will also make it lighter.
A trip to K-Tech after might be a good idea to get its take on where the suspension is, and set it up following its diet.