Team
Nasamax Technical Insight
Renewables and Technical Consultant John McNeil
provides the answers - as we post this on the morning
of the car's debut race at the 51st Sebring 12 Hours.
So
What’s BIO Ethanol?
The BIO indicates that the ethanol is produced from vegetation as opposed
to synthetically manufactured from petroleum products.
What”s
Ethanol?
Ethanol is alcohol. In fact, it’s ‘the’ alcohol in
alcoholic drinks. Beer would be 3% ethanol content, wine 13%, scotch
is 30%. The ethanol used in the race car is 205% proof, which is a bit
too strong to drink neat! In fact, the fuel used by law has to have a
very small percentage of other harmless bio-chemicals added to prevent
people making drinks from it.
Our technical
partner ASTEK specialises in advance technology for the manufacture
of bio-ethanol from materials such as wood, bio-wastes, and
other low-value agricultural produce. In the USA, for instance,
bio-ethanol is commonly manufactured from corn.
At the moment,
producing ethanol from corn is relatively expensive and ASTEK’s
expertise is focused on economic production of ethanol from
low-value bio materials. Using this type of low cost material
does not use up valuable food crops for the production of fuel.
The idea of growing fuel is not new – before motor transport,
farmers used to grow hay and oats for the horses! And some
stiil do.
Ethanol is
going to be used in increasing quantities as an addition to
gasoline to improve combustion. Being a renewable fuel, it
also makes a ‘green’ contribution to the industry.
Environmental pressures are forcing this to happen. Its appearance
in motorsport is timely; ethanol could (and probably should)
become more widely used as a motorsport fuel in the near future.
Why
do you need to use more fuel with ethanol than you would with
gasoline?
You cannot compare the two fuels, it’s like apples and pears. The
critical thing is how efficiently you release the energy available in
the fuel. A teaspoon of sugar has a certain amount of energy. If you
dissolve it in a small amount of water and drink it, you’ve drunk
a teaspoonful of sugar. You could dissolve it in a larger amount of water
and drink it – and you’ve still consumed a teaspoonful of
sugar! The energy consumed is the same, but the volume is greater. If
we’re talking efficiency, all that matters is the energy consumed
and not the volume.
Ethanol has
less energy per unit volume than gasoline. So, just like the
sugar in the water, to consume the same amount of energy as
gasoline you need more volume. The efficiency of combustion
in our engine is actually slightly better than gasoline engines,
in other words it uses the energy in the fuel more efficiently.
Different gasolines have different energy values, which is
why racing regulations strictly control the specification of
the gasolines used to ensure energy equivalence for each competitor.
What
would make a
BIO-Ethanol car equivalent to a gasoline car in the same championship?
It’s not the volume of fuel that matters, it’s the total
amount of energy you’re allowed to carry. We have agreed to run
at a disadvantage for this season to show that this fuel is viable in
motorsport. For the future, there is an easy way to make the bio-ethanol
fuelled cars equivalent in performance to gasoline cars in the regulations.
Equivalence can be based on energy, not volume of fuel. To be equally
competitive, the bio-ethanol fuelled cars need to be able to run the
same stint times. Therefore, the easiest way is to simply change the
capacity of the fuel tank to equate the energy stored in the two different
fuels. The next thing to match is the time needed for the pit stops.
Bio ethanol cars will be putting in more fuel each time. So a change
to the flow rate of the fuel going in makes the pit stops the same time
as well.
What
difference does it make to the car?
Apart from the obvious fuel delivery rate changes, there are fuel system
modifications to cope with higher fuel flows, the materials selection
for fuel compatibility, inlet air management and delivery systems, turbo
charger and injection specifications, ignition timing,
The whole
way the fuel and air is delivered to the engine, and the engine
specification itself, differ substantially when using bio-ethanol.
Is
the car different to drive?
The Nasamax prototype drives in the same way as other sports prototypes,
apart from smelling nicer and being considerably quieter.
What’s
it like working with BIO-Ethanol?
There are no negative sides to it. We’re always surrounded by the
nice smell of alcohol!
Bio-ethanol is less flammable than gasoline, it is not toxic, which gasoline
is, and it’s green. We like it!
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