Response

The Power to Move

I have difficulty believing that a velomobile uses only 1/10th as much power as a normal bike to do 36 km/h, about 30-40 W. Sure, the drag factor is lower, but the cross-sectional area is up. When I read the article I had just done back-of-an-envelope calculations on what speed a Kawasaka z9 motorcycle would do if fitted with the 144V Advanced DC electric motor that people do electric conversions to cars with. It turned out that motor's 20 kW rated power power would get it to about 160 km/h, and its 60 kW peak power would get it to about 225. Put that motor in a velomobile that only requires 35 W to do 36 km/h, take it out to the Desert Lake Racers Association meet on the Lake Gairdner salt flats, and it'd do 425 km/h. Mmmmmmmmmmm. Its hard to believe. Really hard.

Gordon Drennan
Australia

Refer to Page 188, Bicycling Science, by David Gordon Wilson, emeritus professor of engineering at Massachusetts Institute of Technology (MIT).

Normal upright commuting bike - frontal area: 0.55 square metres; drag coefficient: 1.15; power to overcome air resistance at 36 km/h: 345 watts.

Faired long wheelbase recumbent - frontal area: 0.42 metres square, drag coefficient: 0.11, power to overcome air resistance at 36 km/h: 25.8 watts. 

Because anything other than traditional diamond framed bikes are banned from open competition, people don't realise how far pedalling has progressed.

New Falcon Intake

Hi, after reading your interesting article on improving the intake on the EF Falcon (revisited negative boost), i did the same, great story!!! However i went further with the idea and managed to gather more cold air without hacking the bonnet or front guards, thought you might be interested....

http://img70.imageshack.us/img70/2042/new1002101rz6.jpg
http://img396.imageshack.us/img396/485/new1002109qw5.jpg
http://img115.imageshack.us/img115/986/new1002107fx5.jpg

Daniel
Australia

Thanks for that, but we don’t remember hacking the bonnet or the front guards...

Diesels

Hi, I'm enjoying your articles very much. A lot of info. But do you have more info on diesel engines, since I've seen only stuff that can be used on gasoline engines. I would appreciate that very much because I'm driving a diesel 4x4 SUV

Arvin

We have a lot more coverage of diesels coming up.

Spacesaver Pressures

An interesting thing happened to me today. Was buying 4 new tyres for my Honda Jazz (love it!) and the consultant at Bob Jane didn't know what kPa were! I am 44 years old and have managed to get my head around kPa when I only have to think about occasionally, filling my and partners tyres, checking work vehicle (bus). However, they sell, fit and maintain tyres on a daily basis. I also requested my spacesaver spare tyre (TUST), be filled to manufacturers 420 kPa. The consulant and mechanic were almost argumentative about this being to much - "way to high". I pointed out that it is a speciality tyre. They continues trying to convince me less was better.

I guess my concern is, that in the 10 minutes research I did on arriving home, that if TUST's can reduce cornering and stopping abilities significantly, they were advocating putting only about 40 psi into it. I am sure this would be dangerous and further reduce performance. Perhaps an article may be in order re this issue and would be happy for a response when you can.

PS love all the tech stuff you write about. I love my Honda Jazz Auto, very good on fuel, inovative design etc. Why can't Holden and Ford stop worrying about Kw and just make better more relevant cars! After all, we can all get to the speed limit in seconds, so what exactly do you do with your 300 Kw then?  We get the last laugh at the bowser, don't we!!

Michael Stanley
Australia

New Electric Car Batteries

I appreciate your viewpoints on vehicles. Noting that a personal vehicle is a ways off, I wish to point out that battery technology has made a leap forward with nanotechnology being applied. That being said, it should be noted that GM has bought up the patent rights on the (seemingly) best of two products out and is now saying they will use the other battery already being used (A123, power tools) for their car batteries. It should also be noted that GM back in the ninties bought up the patent rights to the osmonic battery, which never saw the light of day on the open market while pulling their electric cars off of the road. In other words, all I see is another ploy to delay the all electric plug-in covered with photo voltaic cells. With most travel in the US consisting of two miles one-way, the use, and price of gas, would drop like a rock if we switched over to the new battery technologies. Heck, we would even have to pour in fuel stabilizers for the plug-in hybrids. Just taking a hybrid now and installing an available battery add-on from A123 puts one in the 150mi/gal. range. You should check it out. Oh, and before I forget, you should also check the output of those available batteries and recharge times. Lithium batteries using nanotechnology has solved the 'burning batteries' problem.

The two lithium nanobatteries are Altairnano and A123. The life cycle for the Altairnano is put at around twenty-three years or 10,000 charges. The life cycle for the A123 is around 2,000 cycles which is higher than the current lithium batteries at around 750 cycles. Also, the recharge time is a lot lower with the newer batteries. These nanobatteries have done away with fire hazard of lithium batteries.

Jay Coleman
United States

EF Falcon Intake

Did you do any 'after' flow recordings of the EF Falcons air intake system at different points

Doug
Australia

No we didn’t.

Too Wide

The Human powered car (velomobile) might in theory be able to go on a cycleway, but in practice my mountain bike often has trouble fitting through all the gates/posts/narrowings that such paths include. It couldn't be done in a velomobile.

Patrick McAuliffe
Australia

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