Can 1983 Honda VT-500 Meet the Vetter Challenge?

[redyaris]

Originally Posted by Frank Lee

The saving grace might be that they don't go 70 the entire time? Or do they?

Is he looking for 100+ mpg, or is it 120 mpg now?

IMHO I knock 15% off the calculated fe values for "real world" driving of cold starts and starts and stops. Hypermiling can get that back and then some but I understand you can't do much of that with Craig behind you.

The Vetter challenge is over 100mpg under Vetter Conditions...

With a much less aero-developed Suzuki GS 500 I got to 83mpg round trip average at a slitly lower speed 60 - 65 mph in very windy conditions, this past summer.

Cold starts are not very much of an issue under Vetter conditions nore is there a lot of start and stop.

I will make no further comment on hypermileing or improved engine efficiancy...

[Frank Lee]

Just FYI or for comparison, here are some frontal area and Cd values for bikes, wind tunnel tested:

Sport Rider-Testing Suzuki Hayabusa and Kawasaki ZX-12R aerodynamics in the wind tunnel

[FXSTi]

Frank Lee,

The link goes to a title page with no links.

Kirk

[redyaris]

Thanks for the link but it is all old info to me, I have read many of K R Coopers papers on motorcycle aerodynamics.
I always have a chuckel when people refer to the Hyabusa as having good aerodynamic's... at a Cd of over 0.6 the hyabusa is double what my Yaris at 0.3 has and its a hatchback! To those in the know most motocycles are notoriusly poor arodynamicaly. Some BMW R100 got down to Cd of 0.45 aprox.

[Frank Lee]

Originally Posted by FXSTi

Frank Lee,

The link goes to a title page with no links.

Kirk

It just worked for me.

[visionary]

This looks like a good project and a reasonable challenge, but looking at your previous work (Gray), I'm sure you will meet your objectives.
It seems to me that the "Vetter Conditions" goal is a moving target. The competitor results are improving as we each learn from one another about how best to meet the challenge. One point that I picked up from Craig's site, was his question about how much horsepower is optimum. The VT500 surely has more than ample horsepower for this task, and that will limit your ultimate FE ability.
With many others turning to smaller (250) motors, what made you choose this route?
Do you have other aims or have you seen something we may have missed?
That's not mean't to be critical, just inquisitve.

I'll follow this build thread closely, and wish you success
Regards
Pete

[redyaris]

Originally Posted by visionary

This looks like a good project and a reasonable challenge, but looking at your previous work (Gray), I'm sure you will meet your objectives.
It seems to me that the "Vetter Conditions" goal is a moving target. The competitor results are improving as we each learn from one another about how best to meet the challenge. One point that I picked up from Craig's site, was his question about how much horsepower is optimum. The VT500 surely has more than ample horsepower for this task, and that will limit your ultimate FE ability.
With many others turning to smaller (250) motors, what made you choose this route?
Do you have other aims or have you seen something we may have missed?
That's not mean't to be critical, just inquisitve.

I'll follow this build thread closely, and wish you success
Regards
Pete

The reason for the VT 500, is that I already own it. The bike itself has dificulty maintaining speed when encountering hills and headwinds, riding at 90km/h and higher in 6th gear. In my view it has more than enough power as you suggest, most of the calculations suggest that 5-8 hp will be enough. It does, like most, if not all production bikes, have poor, or non-existant aerodynamics.
The aproach I am taking is the more dificult one, and will not ever become the most fuel efficient bike in the Vetter Challenge. It does have a small hope of getting to the 100mpg under Vetter conditions, and that is my challenge.
I do get some enjoyement out of solving the problems encountered while designing/building things and that is enough for me. The things I modify/build are also a constant source of entertainment for some of my good freinds... most of whom do the same type of things.

[redyaris]

I have been working on the Honda VT500 to day and the rear suport struckture is taking shape. I will be following Graig Vetters lead and make the rear aero cargo section removable with only 3 or 4 bolts. which will make maintainance and tire changes very easy. The front end body work is taking some time to resolve. The problem is where to change the angle of attack of the fairing so that it ends as close as posible to the horazontal, at the shoulder level of the rider.

[redyaris]

Some pic's of the project, What I am working on is the structure to suport the variouse outer body work. The end of the long channel section Is where I will mount the rear license plate, tail/stop lights, and turn signals. the front view shows a air deflector for the radiator, between the forks and below the head light...

[low&slow]

Great progress, thanks for the pictures.