Random Aerodynamic Oddity of the Day Thread

[cRiPpLe_rOoStEr]

[kach22i]

Originally Posted by cRiPpLe_rOoStEr

Makes me wonder how it would fare with a mid-mounted Honda CB 500 engine and RWD instead of the stock powertrain.

Not too well in my opinion, center of gravity needs to be way up front so that all three wheels carry near equal weight. Designs that do not do this attempt to compensate with massive rear wheels, but they are fighting physics.

At the 46 minute mark Robert Q Riely explains, I watched the whole video, a bit slow but very informative.

XR3 Hybrid 125-mpg Three Wheel Vehicle

https://www.youtube.com/watch?v=n4FQF8ziwng

This is the introductory presentation of the XR3 Hybrid to the Arizona-Nevada Section of SAE International in September 2008, soon after completion of the prototype. The speaker is Robert Q. Riley, the vehicle's designer. More information is available at http://www.rqriley.com/xr3.htm

His website is down, read this:

Posted on March 15, 2022
A Belated Note on Robert Q Riley of Trimuter and Tri-Magnum Fame
https://thekneeslider.com/a-belated-...i-magnum-fame/

I took an image at the below site and attempted a mark-up based on where his laser pointer was and other documents.

https://protected.hostcentric.com/rqriley/xr3.htm

[redneck]

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kach22i

His website is down.

Probably because he died a couple of years ago...




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[cRiPpLe_rOoStEr]

Originally Posted by kach22i

Not too well in my opinion, center of gravity needs to be way up front so that all three wheels carry near equal weight. Designs that do not do this attempt to compensate with massive rear wheels, but they are fighting physics.

Maybe carrying equal weights on all 3 wheels wouldn't be so beneficial at all. A single rear wheel carrying a more weight than each front wheel, or around the same weight that a pair of front wheels would carry could eventually get better traction under certain conditions.

[kach22i]

Originally Posted by cRiPpLe_rOoStEr

Maybe carrying equal weights on all 3 wheels wouldn't be so beneficial at all. A single rear wheel carrying a more weight than each front wheel, or around the same weight that a pair of front wheels would carry could eventually get better traction under certain conditions.

Great theory, build it and see what happens when you ignore lateral force.

I'm taking clues from the two guys that successfully designed and built several trike models (Robert Q Riley and Ron Will), and the physics probably hasn't changed much in all that time.

It's quite the investment of time to watch the video I posted, think it took me 2-3 attempts to get all the way through and I had to find something to do like sketch at the slow parts, but I'm glad I made my way though it.

I welcome any discussion based on that video.

I simply do not have the time nor energy to dispel all the theories in this forum.

EDIT: Without the 4th (rear) wheel stabilizing your platform (0.8 lateral G = street tire performance) I doubt the benefits of powering out of a corner Porsche 911 style with a rear weight biased reverse trike will mitigate or equal out to the forces forcing one to slow down coming into a turn.

The rear of a motorcycle reverse trike designs that do NOT place the occupants far forward (T-Rex and Tanom Motors) use really wide and sticky summer tires. We can argue if this is a performance market thing or just what they have to do to keep the cars from sliding off the road. One could say that the Polaris slingshot front engine reverse trike also has pretty wide tires, but again I see minor flaws in it's weight distribution, and would say this is a performance segment vehicle not economy segment vehicle.

The Robert Q Riley designs and Ron Will's Turbo Phantom were a nice balance of performance and economy in my opinion.

Ron Will’s Turbo Phantom
https://www.deansgarage.com/2012/ron...turbo-phantom/

Against a dozen other cars, we came out on top, with excellent handling, and stability, generating more cornering G-forces than many four-wheel cars.

https://fiberclassics.org/turbo-phantom-reverse-trike/

This very wide (around seven feet) trike was powered by a Honda Goldwing, had VW front suspension and MG steering, and had a 0-60 time of about 6 seconds, a top speed as high as 140 mph, and turned at 0.82g. The body was built using a urethane foam and fibreglass sandwhich (like the RQ Riley designs such as the Tri-Magnum) and had an integrated steel roll cage. When the canopy opened, the steering column and dashboard lifted along with it.

[kach22i]

I like this in a quirky way, but from what I've read those front wheels should be a little father apart.

https://forums.pelicanparts.com/off-...ures-2590.html

[Bicycle Bob]

That looks like it was greatly affected by available hardware, and not at all by a clean sheet of drawing paper. I wonder how it is cooled. Snowmobiles use water cooling from a flat tank getting sprayed with snow.

[cRiPpLe_rOoStEr]

Originally Posted by kach22i

Without the 4th (rear) wheel stabilizing your platform (0.8 lateral G = street tire performance) I doubt the benefits of powering out of a corner Porsche 911 style with a rear weight biased reverse trike will mitigate or equal out to the forces forcing one to slow down coming into a turn.

I wouldn't go that far, so a CB 500 engine which is not so heavy would be OK for a moderate usage, instead of the 3-cyl fitted to the stock Insight. As far as stability goes, it's worth to remind the Isetta which had the rear track so narrow that even running 2 rear wheels they were so close they acted nearly as a wider single rear wheel.

[kach22i]

Full 90 Days Homemade Porsche 918 Spyder from PVC Pipes

https://www.youtube.com/watch?v=mgKXaGf_1YY&t=610s

[freebeard]

That's a lot of finish work that won't last more than tens of miles. The egg-crate foam interior is a nice touch, though.

An I-16 built since 2019:


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https://justacarguy.blogspot.com/202...reamliner.html

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Aerodynamic tractor of the day:


https://justacarguy.blogspot.com/202...ctor-look.html