Side View

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Side View

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FJ New Nose

This side view shows the 'inverted aerofoil' section that is the dominant section. This continues, in a cleaner and wider form than the previous section, under the nose and should improve flow to the radiator intakes. This shape is intended to kill positive lift rather than provide significant download - while providing low drag.

The sharp cut-off to flat on the upper surface is intended to eliminate any pressure wave off the surface and maintain coherent flow onto the 'conning tower' section and into the headlight opening, which is actually an intake duct for the heater and rear screen duct.

FJ's new nose

Aha! The moment we've all been waiting for has arrived! FJ has progressed from bright yellow running shoe to bright yellow clog, or maybe acanthostega skull? But if it does the job it was intended to, what else matters? How much closer will this bring us to an aerodynamically 'ideal' compromise FF shape?

Some early results, March 2006

I've chosen this picture because it shows what may be some usefull relationships between nose and tail.

So far this shape has only been run up to about 60 mph on urban motorways, some in heavy rain and moderate gusting wind.

Indifference. Early indications are at too low a speed to be significant, but there is a sensation of absence of any aerodynamic effect compared to the previous section. Complete indifference at 50-60 mph motorway. However, there is a detectable difference in response to gusting at very low speed (urban) but I haven't worked out what it is yet - might be that absence of aerodynamic effect.

Imoprove flow into radiator ducts. Definite improvement here, slight but noticable at urban speeds with a marked increase in cooling above 30-40. Thermostat closed at 50. Better than expected, throws light on the difficulties getting V05's rear rad. to work, undernose, keel, Is important

Cockpit enviroment. Expected improvement, especially marked above 30-40, with quite sudden onset of coherent flow off windscreen and 'quiet cockpit'* This flow shows marked transverse flow indicating that the conning tower is acting as a vertical 'spliiter' rather than a transverse 'wedge'. Some indication of very strong screen duct flow 'leaking' into cockpit, some very fine spray on glasses at 50-60, may need vane to keep it on the screen.

Lowest speed 'rain in cockpit**' hasn't changed much, probably 20-25 rather than 25-30, and although, by 30 rain drops can be seen being blown overhead, other raindrops still hit the riders face untill above 30.

Unexpected and probably significant improvement in general airflow over the upper half of the vehicle. Even at these moderate speeds in dirty air, clear streamlines formed on the upper tail,indicating that cockpit pressure is maintaining clean airflow over the upper half of the cockpit opening. If this is maintained at higher speeds it should noticably reduce drag. It is possible that this improvement in flow over the tail plays a part in the improved cooling performance.

Problems. There is light reflection up the screen duct, directly off the tops of the headlights onto the screen. This is an 'effect' rather than a problem, the duct is already painted black, but some addtional part of the 'tray in front of the lights will need to be so too. May tape over upper edges of light units.

Further study. Apart from results from higher speeds it will also be interesting to discover the flow over the nose. At present the paintwork is too new for lines to form but spring flies and hopefully wool tufting will give some idea. Controlling the screen duct with a possibly adjustable vane (For cold air in cockpit) can wait untill the full range of flow has been experienced.

*Quiet Cockpit, airlfow off the ears, no direct wind noise, onset now more definite - there's still a Reliant engine and a Guzzi gearbox going off in there...

**Rain in Cockpit, The point at which rain starts to hit the rider's shoulders, reminding them they should be wearing suitable outdoor clothing.

Royce, March 2006

New nose, Interim Results. May 2006

This shape has now been run up to English motorway speeds in traffic, with varying winds, although not specific strong sidewind.

Excellent. Probably better than the Production Voyagers, similar to 001 Ducati. No reaction to nearby vehicles. (no large trucks available) Stable, noticable directional damping. (slightly spooky compared to previous shape performance)

At least as good as previous shape, no apparant 'wall' effect, needs fuel consumption record,further higher speed/wool tufting data. (traffic on test track)

Download/negative lift.
Less lift, or more download, than previous shape, no noticable aerodynamic effect going through the 60-80mph range. "Less effect" sums up most of the aerodynamic qualities of this shape.

Slight improvement at speed, but more marked improvement at low/medium speed. Suggests that previous shape worked well at speed and this shape extends that function into lower speed ranges. Pictures of underside shape comparisons to be posted shortly.

Cockpit environment.
At least as good as UK-style open topped sportscar (MG,Healey Etc.). Screen duct needs refinement to clean up cockpit flow. Best yet.


Wool turfting and dirt tracking may show that detailing like the various flow separators should be extended or reduced but results so far suggest that this is a very good basic shape for open-cockpit FF's. It appears to be a step forward in stability and drag from the Production shape.

Hopefully a video record can be made of the wool tufting tests and some commentary can be provided, detailing the specific elements of this shape.

Royce Creasey May 2006

New Nose, Final results

New nose, Final results. July 2007

The new nose has now been run through the normal performance envelope. This includes being knocked over twice while parked.

Clearly acceptable. There is some indication that the horizontal separators along the sides of the nose are unnecessary. Use on motorways is undramatic.
There is a hint that the slow curve of the sides of the 'conning tower' part of the nose may cause slight buffeting in turbulent wake, but it is difficult to reproduce this effect. The production Voyagers have indicators fitted in this place, deliberately providing separation. It might be useful to provide a slight separation line in this area. Dirt tracking shows a broad margin between laminar and separated flows. This is susceptible to a wandering separation line and associated buffeting

Better than the previous shape, vehicle accelerates continuously at high speed. fuel consumption at steady motorway speed apparently best yet. No formal testing has been done but several full tank motorway journeys have been made.

Download/negative lift.
May settle slightly at high speed but detectable 'nose-down' attitude may just be the rear end jacking up under high torque. No stability problems noticeable on fast turn in.

Cooling has been improved recently by other measures, but motorway runs during high winds indicated ample cooling in tailwind.

Cockpit environment.
Generally good enough to de-motivate significant changes. There are various minor problems that could be eliminated by simple mods.
The leg opening upper edge does not have a lip, like the Production Voyagers and water enters the cockpit at moderate speeds, wetting the thighs slightly.
The airflow through the screen duct is noisy at high speed and the flow is excessive for the 'virtual screen' role. It is planned to split it, diverting part of the airflow into the cockpit, to improve pressurisation and reduce the virtual screen effect.
It would still be helpful to fit a lap cover for rain in low speed situations. Sitting on a motorway, bored, it is easy to discover draughts, face buffeting and excessive noise. Running down any other road at similar speeds, having fun, the environment is entirely unnoticeable.

I believe this is a very good basic shape for open-cockpit FF's. It appears to be a step forward in stability and drag from the Production shape. However Athur Middletons body shape, basically similar but without any notches or separators - and relying on externally mounted lights to brake up the airflow - demonstrates that there are many ways to meet the basic requirements of stability, low drag and indifference.

Hopefully a video record can be made of the wool tufting tests can be provided in due course.

Royce Creasey July 2007