What is required in the age of "eco-cars"
It is a harmony between "individual satisfaction" and "social demand".
Nowadays, car tuning is required to be more social.
Even if it's not as fast as the press touts, the era of eco-car majority will come sooner or later.After all, there is a social cause to stop global warming, and fossil fuels will eventually run out, so we can't argue.
In that case, as a matter of course, it is feared that there will be a growing tendency to criticize mass-produced vehicles for users to modify them later.This is because there is a deep-seated prejudice in Japanese "remodeled cars" that have a strong impression born from the desire of some individuals for antisocial performance.It's a good nuisance for modern tuning enthusiasts with social decency.However, there is something to be done before mourning the damage caused by rumors.It is about evolving the way tuning itself is done and striving to gain social recognition.We at AutoExe are proud to have been at the forefront in that sense.And I would like to continue to challenge to create the fun of tuning with my brothers who share the same values as us.
It is dangerous to think of "km / l" as all the evolution a car should seek.
There is the word "fundamentalism".The idea is to force others to follow, with their beliefs as the only absolute value in the world."Eco-fundamentalism (?)", Which argues that all human activities should contribute to the reduction of CO2, cannot be said to have the potential to proliferate as a progressive ideology in the current climate.
If not, cars that make you feel such a danger have already begun to appear in the marketing of manufacturers.Especially for cars that claim outstanding fuel efficiency, they adopt a unique aerodynamic style that sacrifices practicality to earn fuel efficiency in the high-speed range, and are oriented toward fuel efficiency even in the invisible areas such as tire performance tuning and how the brakes work. It seems that the design of is prioritized.If the result of fuel economy competition leads to a denial of inconvenience and enjoyment of driving, it would be different from the original evolution.The original normal evolution is to aim for better fuel efficiency while firmly controlling what the occupant wants from the car, its functions and uses, as well as its design and fashionability.
For example, personalization of styling. There is also craftsmanship that minimizes the deterioration of Cd.
We have traditionally called "styling kits" for body parts that are commonly referred to as "aero" in the after-parts world.Parts such as the front grille and bumper spoiler are not only related to aerodynamic performance, but also have important value as part of the rider's self-expression.
Of course, it does not mean ignoring aerodynamics as a function, but it does not mean that the increase in the front projected area and the deterioration of Cd (air resistance coefficient) are minimized, and if possible, the CL (air lift coefficient) is reduced to grip the tire. There is also the aim of improving power.However, I wanted to make a clear distinction from this downforce-seeking aero.
Even so, a small organization like us cannot have a wind tunnel test site.The actual vehicle wind tunnel owned by the manufacturer probably costs billions of yen in construction and maintenance costs are enormous.Therefore, it is usually forced to model by craftsmanship based on experience and intuition and evaluation based on actual vehicle driving.However, it's still enough because it's not a basic styling mess, it's just an additional or partial change.
However, with the growing eco-consciousness, many users may be worried, so this time we brought the new Axela styling kit-equipped car to the wind tunnel made by a big aero maker in the after-sales. So, I did the test for the first time in a long time.
Since each wind tunnel has something like individuality or habit and there is a considerable difference in the measurement result, it is not possible to directly compare it with the value announced by the manufacturer, so it is a simultaneous test with a standard rental car. I asked for the relative tendency, but if I write the result raw, I got the data that Cd = 98.5% and front projection area = 100.2% compared to the standard specifications.Since the air resistance is proportional to the product of these two terms, a simple calculation is 0.985X1.002 = 0.987.
It's a private wind tunnel, so I'm not going to insist on it as an "eco-style that goes beyond standard cars."Considering the error, an evaluation of "almost the same. At least there is no significant deterioration." Is appropriate.By the way, the lift surely turned downward and generated a slight downforce.The appearance is a matter of taste, but I am proud that the simple and dynamic look that eliminates the complicated decoration of mass production specifications has created an intellectual atmosphere while being sporty.This is an example of how unique design and social aerodynamic performance do not necessarily contradict each other.
The harmony between individuality and sociality is the New Driving Sensation that the times demand.
The standard specifications, which were destined for mass production, are forced to have an excessive margin for universalization and popularization in terms of comfort and reliability.Until now, we have considered that the basics of tuning are to carefully determine the margin and to cut off the excess part and utilize it for people who enjoy driving.Don't be afraid to say bad things, fuel economy in the age of eco-cars is not a sanctuary.Of course, there are limits, but I am sure that we will find a balance that does not go against social decency.That is the "New Driving Sensation" that is born from the new sense of driving that we advocate, the happy harmony between individuals and society.
How to control "km / L"
Basic knowledge of fuel consumption calculation that balances eco and ego.
"Km / l" is dominated by the energy efficiency of the prime mover vs. the magnitude of running resistance.
Various resistances occur in a moving car depending on the situation.It is a force that gives a negative acceleration.Therefore, in order for the car to continue running at the same speed, it must be canceled with a positive acceleration equal to the sum of these resistances.That is the driving force supplied to the tires from the prime mover such as the engine and motor via the driving device.
If one gasoline engine vehicle consumes b (ℓ) of fuel when traveling a (km), the energy loss during that period is calculated as total running resistance (N) x 1,000 a (m). can.This is because energy (J: joule) = force (N) x distance (m).On the other hand, the energy supplied during that period is the efficiency of the energy contained in gasoline (J) x the prime mover system (including the drive system) of b ℓ.As a result, since they are equal, the fuel consumption rate a / b (km / ℓ) is proportional to the efficiency of the prime mover system and inversely proportional to the running resistance.It is because of such a fuel economy structure that eco-cars aim to reduce running resistance at the same time as improving the efficiency of engines and transmissions.
>> Calculation formula for lost energy and supplied energy
As a brain teaser, you don't need a supercomputer to calculate the fuel consumption rate.
The normal fuel consumption rate is measured by a test with actual vehicle driving, but the outline can also be calculated on the desk.Since it is a simple principle level, it is not possible to accurately trace the numerical value of the actual vehicle under precise control, but only the tendency can be grasped.Since energy (J: Joule) and power (N: Newton) are the opponents, it may be a little difficult to get into the humanities brain, but it is such an era.There are also simple explanations on the internet, so please refer to them and try to understand the origin of fuel efficiency.There are four types of running resistance applied to the car, and each calculation formula isThis is the street.It looks complicated, but if you calculate only the unit, everything is mass (kg) x acceleration (m / s2), that is, (N: Newton).Loss energy (J) can be obtained by multiplying the total running resistance (N1 + N2 + N3 + N4) by the running distance (m).
Since the energy content of gasoline is known to be 44,000,000 (J / kg), it can be calculated as 0.75 (J / ℓ) by multiplying it by the specific density of 33,000,000.Multiplying the amount of gasoline consumed (l) gives the energy supply (J).
After that, if you enter the necessary data in the formula "loss energy = supply energy", you can calculate the fuel consumption rate.
-Simulation 40 Energy efficiency in "XNUMXkm / h cruising".
・ Simulation XNUMX Effect of "change in running resistance" on fuel efficiency.
Stepping on the accelerator has a big effect.The problem may be "km / person".
Therefore, the effect of tuning within a certain moderation on fuel efficiency is limited, and it is not a level that is denounced as antisocial in itself.However, the problem remains.This is because the simulations up to this point are constant-speed driving on flat roads, and are premised on "quiet driving".Of course, if you tune it, you will want to run accordingly.Since it will speed up and expedition to the mountain pass, I calculated "km / l", which can be said to be the price of desire in such a situation, with a model vehicle.
In the extreme case, if you try to get an acceleration of 5.0km / h to 40m / s4.0 while climbing a slope with a slope of 2% (whether it is actually possible or not), a fuel consumption of 0.77km / l is calculated.Since the spreadsheet model is uploaded on the Internet homepage, the rolling resistance coefficient, vehicle weight, Cd, vehicle speed, gradient, acceleration, etc. are changed to estimate the fuel consumption according to the tune of the brothers and the image of how to run. I want you to try it.
In normal driving where various accelerations and decelerations are repeated, of course, fuel efficiency changes depending on how you drive, so your social responsibility is probably the "km / l" displayed in the catalog of your car. Instead of being satisfied, the question should be "km / person" per year or month.Fuel economy is not just the performance of a car as a machine, but the output of a system of "car + person".Without that recognition, it is unlikely that we will be able to enjoy the "Fun to Tune" of the coming era.
