An acquaintance in the UK sent me a glowing review of the 2014 VFR800 that's in the June issue of the magazine Motorcycle Sport & Leisure. The first page (only) is posted on their site. Posting the whole thing would be copyright infringement, I suppose, but there's an interesting short sidebar on VTEC that would seem appropriate at this point in the thread and should be okay legally (for educational purposes :wink: ). I cut out one or two of the less interesting Q&A's to make it more of an excerpt than a copy:
Masatsugu Tanaka –
Honda VFR800 project leader
What’s the advantage (of VTEC)?
The VFR’s cylinders have four valves, but it only operates two initially – one inlet, one outlet. This means that at low revs, we are able to achieve the torquey power curve that a two-valve motor offers. At a certain rpm, the other two valves – diagonally opposite to optimise gas flow – come into action, delivering four-valve performance. Four-valve motors achieve better performance at higher revs, which means we can deliver a strong flow of power from very low revs all the way up to the bike’s limiter. It gives the rider the best of both worlds.
Why is it not on other Hondas?
It is. The CB400 Super Four – a purely Japanese model – also uses the system. It is a big seller in Japan, because of capacity legislation and another of our premium products. We would fit it to more models if it made sense, but it is an expensive technology and it also is quite heavy. For these reasons, we’ve had to limit its instalment.
So we’re not going to see it on your V4 GP bike?
No. I think it would give the motor some advantages, but not enough to pay off the additional weight. Besides, on a race bike, the power focus is always right at the top end. It wouldn’t make sense to chase the low power performance.
Didn’t the VFR1200F warrant it?
It didn’t need it. The sheer size of the motor was sufficient enough to produce the desired performance we were after. We would have considered it if necessary. VTEC is best suited to mid-capacity bikes. The CB400 is as small as we’d ever look to go with the technology and the VFR800 is about as big as it would suit.
How have you improved the flow of the VTEC?
There are two main ways. The first is the exhaust, which has been lengthened and reshaped to help the gasses flow. The second is in the
fuelling. The hardware remains the same as the previous models, but we’ve altered the frequency and volume of fuel fired into the cylinders. The combination of both of these has helped to lessen the glitch between the 2-valve and 4-valve transition.
There's also a two-page spread that includes the various generations, but they call the 2014 the 6th gen. Here's how they break it down: 1986 VFR750, 1st gen; 1990 VFR750, 2nd gen; 1994 VFR750, 3rd gen; 1998 VFR800FI, 4th gen; 2002 VFR800 VTEC, 5th gen; and 2014 VFR800 VTEC, 6th gen.
And there's a second, longer sidebar that is an interview with Honda Assistant Chief Engineer Kanji Hayashi. Among the things he explains: 1.) They considered changing the frame, but decided they couldn't substantially improve upon that of the 6th gen (2002 and up). Instead they went after things like the under-seat exhaust (5 kg weight savings) and new aluminum subframe (2 kg less); 2.) Spokes were added to the wheels not for looks, but to smooth the ride--there is no weight savings; 3.) Two-piece forks also saved weight; 4.) The radiators were moved to the front to narrow the bike; they had to stay with two radiators because a single radiator large enough to do the job would interfere with the wheel; 5.) They kept the dimensions the same (rake and trail) to keep the same excellent compromise between sport and touring; and 6.) They kept the single-sided swingarm for its torsional rigidity and distinctiveness.