View Full Version : Building for efficiency instead of performance
Greenbeast
23rd September 2011, 07:49 AM
I'm wondering about the Roadster as a platform for an ultra-efficient petrol car or all electric vehicle.
I currently drive a citroen c1 which can do 70mpg+ (extra-urban).
I was wondering about the possibility of putting one of these engines in the roadster to gain even more mpg.
Thoughts anyone??
Talonmotorsport
23rd September 2011, 08:18 AM
I have supplied a few chassis to a training centre who have put 2 very large electric motors running through a type 9 in to a tiger chassis. The only problem is that for every 5 miles of driving you need to carry a 5kg battery which takes 12 hours to charge. Have you considered using a small NA diesel with a turbo? Don't use a turbo diesel just a NA with an added turbo, this means it has smaller injectors so good for economy but burns the fuel more efficiently. You could always get one of those under car mounted speaker sytems so that you can mask the diesel rattle :D
Greenbeast
23rd September 2011, 08:24 AM
I've done a bit of research into the electric side of thing, and i may go that way.
What do you think about the ease of fitting a different, much smaller engine in?
I like my little c1, it's quite perky round town and can handle the motorway with ease, fitting it's engine into something that weighs 2/3 as much should improve acceleration but also overall efficiency, no?
twinturbo
23rd September 2011, 08:36 AM
I would find an efficient Oil Burner, or try LPG + Petrol.
Electric vehicles just shift where the energy is created, it's often created by power stations that waste fuel as they can't produce on demand efficiently. The Batteries cost a lot to make, transport and to dispose of. Add to that the total in-convenience of having to find a charging point and they realy make little sense.
Even a relativly old VW 1.9TD will probably see into 60-70's if driven conservativly in a roadster. You may have to calculate so gearing ratios to keep the engine at it's optimum.
TT
Greenbeast
23rd September 2011, 08:41 AM
I'm comfortable with the downsides of all-electric, i'm weighing up the options.
Where i'm not sure is the donor engine business. I already see 60-70mpg with my current petrol, surely i must be able to easily beat that in a roadster?
What potential pitfalls might i see using a unusual donor engine/drive train?
twinturbo
23rd September 2011, 09:24 AM
Gearbox is the usual sticking point, otherwise we would have all sorts of tasty engines in frequent use.
And Complex Imobalised Engine management systems.
TT
Greenbeast
23rd September 2011, 09:29 AM
I'm gonna really show my ignorance here but how come you can't just use the original gearbox?
voodoo
23rd September 2011, 09:53 AM
Most modern cars have transverse mounted boxes as they are FWD, the roadster has RWD.
Personally I have been looking at the feasability of running a NA diesel on Biofuel, in addition we are working with a local company that has developed a biodegradable alternative to GRP. Strengthwise it is better, costwise it can't get close.
Matt
AshG
23rd September 2011, 09:54 AM
personally i think your wasting your time. the roadster has the aerodynamics of a brick. the best way to gain efficiency is to move the car through the air more efficiently.
typically a 2.0 zetec will do between 35-40mpg in something like a focus. have you ever asked yourself why it still only does 35-40mpg in a 7 which is less than half the weight of a focus?
Greenbeast
23rd September 2011, 10:22 AM
Voodoo, thanks for that, knew it'd be something obvious.
Ash, good point
brainbug007
23rd September 2011, 10:47 AM
Personally I like the sound of using hydrogen. Apparently you can run a petrol engine on it with very little conversions. The tricky bit is getting a tank or some sort of electrolisis process running in a cell that creates enough hydrogen to run the engine from salt water.
brainbug007
23rd September 2011, 10:52 AM
Have a read of this, looks cool:) http://www.spiritofmaat.com/archive/watercar/h20car2.htm
flyerncle
23rd September 2011, 11:02 AM
Build your own anaerobic digester and run it from the gas it produces,methane as per Top Gear.
It's very simple to do .
Greenbeast
23rd September 2011, 11:07 AM
personally i think your wasting your time. the roadster has the aerodynamics of a brick. the best way to gain efficiency is to move the car through the air more efficiently.
typically a 2.0 zetec will do between 35-40mpg in something like a focus. have you ever asked yourself why it still only does 35-40mpg in a 7 which is less than half the weight of a focus?
However i just thought perhaps this is because the drivers are tearing round in them rather than driving conservatively? :D
flyerncle
23rd September 2011, 12:14 PM
Wait until you have built and conserative goes out the window.;)
Greenbeast
23rd September 2011, 12:30 PM
ha ha, yeah i bet
davedew
23rd September 2011, 01:20 PM
addition we are working with a local company that has developed a biodegradable alternative to GRP. Strengthwise it is better, costwise it can't get close.
Matt
Does this mean that if you leave it out in the rain, the body will go soggy and fall off!!
robo
23rd September 2011, 04:06 PM
The council round here were playing with cng <compressed natural gas>. I dont know what came of it but i know other countries are bigger into it. Takes all night to compress the gas in a car to give you app 300 miles of driving. Ok for normal town stuff but would cause a rep a few problems. And of course no duty on that or filling stations. Hmmm
Thoughts
Bob
tex
23rd September 2011, 04:26 PM
personally i think your wasting your time. the roadster has the aerodynamics of a brick. the best way to gain efficiency is to move the car through the air more efficiently.
typically a 2.0 zetec will do between 35-40mpg in something like a focus. have you ever asked yourself why it still only does 35-40mpg in a 7 which is less than half the weight of a focus?
beat me to it - if your after an efficient car you wont get it with a 7 type shape - too many sticky out bits.
BUT there are alternatives like the fisher fury type car - basically its a 7 under the skin but slippier cos of body shape
ayjay
23rd September 2011, 07:04 PM
I was thinking of a great big elastic band:D :D :D
Greenbeast
23rd September 2011, 08:10 PM
beat me to it - if your after an efficient car you wont get it with a 7 type shape - too many sticky out bits.
BUT there are alternatives like the fisher fury type car - basically its a 7 under the skin but slippier cos of body shape
thanks, i'll look into it
voodoo
24th September 2011, 08:00 PM
Does this mean that if you leave it out in the rain, the body will go soggy and fall off!!
No, bio-degradable and water soluble are two different things ;)
It is a cellulose resin composite using a hemp based mat and no, you can't smoke it :)
Matt
robo
24th September 2011, 09:30 PM
http://westfield-world.com/pics_paulr.html
Bob
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