improve aerodynamics

[pmera91]

Hi all,

Is there anybody that tried to improve aerodynamics (mainly to reduce dragging) on his Dacia Spring?
The car seems to have a really too bad CX, that of course impact who use the car especially on motorway.
Consider that our Spring has a CX of 0.42, while tesla model 3 has half the CX (0.21).

I was thinking about covering the area below the engine, and try to crate a flat cover to have a smoother airflow, considering that the car is not going really fast, then investigate on other aspects.
Anybody would like to participate?

 

[Fahrer]

I am thinking the same. It will be a terrible aerodynamic! How it is possible to build a new car in such bad condition The first for me is: why there is so much noise by the wind? The second: why giving little tires and than not looking for the aerodynamic? Not only this, for me it is a terrible looking car. At the Tesla you can see they tried to do everything (nearly) for saving energy. At Dacia I think they could also take the look of the old beatle and it would be better. But however. I agree, but I cant work against. There are other things in my life. But I am very interested in your ideas. Hope you will show us some of them.

 

[Lodgy]

Hi all,

Is there anybody that tried to improve aerodynamics (mainly to reduce dragging) on his Dacia Spring?
The car seems to have a really too bad CX, that of course impact who use the car especially on motorway.
Consider that our Spring has a CX of 0.42, while tesla model 3 has half the CX (0.21).

Anhang anzeigen 11472
I was thinking about covering the area below the engine, and try to crate a flat cover to have a smoother airflow, considering that the car is not going really fast, then investigate on other aspects.
Anybody would like to participate?

I'm very excited about your conversion and results!
Here would be a 0.23(!) result:

Citroen C10 in Tropfenform/ Teardrop shape inspired by Aircraft construction

 

[pmera91]

I am thinking the same. It will be a terrible aerodynamic! How it is possible to build a new car in such bad condition The first for me is: why there is so much noise by the wind? The second: why giving little tires and than not looking for the aerodynamic? Not only this, for me it is a terrible looking car. At the Tesla you can see they tried to do everything (nearly) for saving energy. At Dacia I think they could also take the look of the old beatle and it would be better. But however. I agree, but I cant work against. There are other things in my life. But I am very interested in your ideas. Hope you will show us some of them.

IMHO they just tried to take the cheapest renault car (that currently has petrol engine for a good part of the world) and invest as less as they can to have the first EV on the line.
Therefore, I was searching online if there are affordable and trustworthy ways to measure gains after the improvements.

 

[pmera91]

I'm very excited about your conversion and results!
Here would be a 0.23(!) result:
Anhang anzeigen 11480
Citroen C10 in Tropfenform/ Teardrop shape inspired by Aircraft construction

that could be a dream

 

[pmera91]

My limits are:

1) The optimization should not modify the body of the car in absurd ways (like that

): IMHO this is too much, and also I don't want to struggle with police to explain them that my car is 50 cm longer just for efficiency purpose, because I would need to take that to test and that could be a real mess

2) I bought my car first for it's medium term economical efficiency, so the poor man solution would be preferred over an expensive solution.

3) Car is enough cost-efficient, I am studying that topic with the purpose of having higher efficiency on highways mainly to not stop charging so often.

4) No springs to lower the car, and possibly no mechanical changes

My main goal is:
In 3 months I would start doing 2x week a trip of 180 km with 80% highway and 20% city. During last summer I did that 1 or 2 times with a Dacia Spring in ECO mode (actually was a testdrive car) and I was able to reach the target destination with 15% of remaining charge.
Considering the same trip, I would like to AT LEAST obtain the same result even in winter time (considering heater and 20 degrees of difference), so, considering that the heater consumes +- 1 kw, with 3 hours, I would need to gain 3 kwh from battery, so assume a huge 15% gain needed to fulfill the request.
Also, I would like to use less the ECO mode on my car driving more closer to the blazing fast speed limit of 120 km/h ( that suddently goes down to 80, than 100, than 80... It's Swiss... speed cameras... slow speed limits...)

What I would need:
1) check if someone else built up parts that I would need (ex Diskussion zu Dacia Spring - Engine metal shield)
2) check for a DIY yourself shop where I could find useful materials
3) Time and possibly help

 

[pmera91]

What could be the first things I would like to start working on:
- Covering all the ground of the car to reduce the drag and let the air flow in the best possible way, without compromising stability
- Studying spoilers (front, rear) to reduce air flowing in the low part of the car and the drag on the rear
- Better rim covers to reduce dragging on the side of the car and let air flowing more smoothly
- Removing some unuseful parts like the roof bars (come on... I would never load my car with something on the roof and I would never use them at all.
- Close as many holes as we can in the front and eventually smoothing the front splitters and airdam

Waiting for your suggestions and consider that I am an engineer but in a totally different field

 

[Fahrer]

What I would need:
1) check if someone else built up parts that I would need (ex Diskussion zu Dacia Spring - Engine metal shield)
2) check for a DIY yourself shop where I could find useful materials
3) Time and possibly help

The only thing I know is the engine metal shield and nothing else. And the result of the shield for the KW , I believe will be nearly nothing. But I have not tried it...
Oh your news came earlier: Spoiler: ok, but in Germany not possible whithout papers. Covering the ground: could be a problem for the battery temperature. At my trip to Italy I had problems to cover the temperature to 40°C, and I was happy that the air blows under the car. Whether this was a help I dont know, but without it could be a pitty.

 

[Lodgy]

Waiting for your suggestions and consider that I am an engineer but in a totally different field

I've already seen this on a blue Spring158€The cardboard version from the videos is of course much cheaperJust as ugly but cheaperI would have removed the roof rails a long time ago if my wife and brother-in-law hadn't objected..And so I dream of making my Flyke aircraft more efficient. Nobody can talk me into it. The use of acrylic sheets was also very interesting for me. Thank you for that
German proverb: Dem Ingenieur ist nichts zu schwör or Nothing is too difficult for the engineer

 

[fraggl]

The car was never designed to be an efficient EV. They just took the Renault Kwid (actually a combustion engine car) and put an electrical powertrain into it. For city speeds this is more than good enough.
For longer motorway distances, it can become a pain if you really want to go faster than 100 km/h.

With all that you plan to do, you can easily calculate the ROI: You have to invest in several things, probably a few hundred € and may gain like 15% or 3kWh capacity and most likely only in the sector above 100 km/h.
So the immediate ROI per one drive would be ~1€ depending on the electricity costs. Meaning, you would have to do these "high-speed" rides at least a few hundred times. If you do so, fine, else forget it.

 

[pmera91]

The only thing I know is the engine metal shield and nothing else. And the result of the shield for the KW , I believe will be nearly nothing. But I have not tried it...
Oh your news came earlier: Spoiler: ok, but in Germany not possible whithout papers. Covering the ground: could be a problem for the battery temperature. At my trip to Italy I had problems to cover the temperature to 40°C, and I was happy that the air blows under the car. Whether this was a help I dont know, but without it could be a pitty.

Good point, considering that I am frequently in hotter places I will pay attention on the blowing flow on the battery

 

[pmera91]

The car was never designed to be an efficient EV. They just took the Renault Kwid (actually a combustion engine car) and put an electrical powertrain into it. For city speeds this is more than good enough.
For longer motorway distances, it can become a pain if you really want to go faster than 100 km/h.

With all that you plan to do, you can easily calculate the ROI: You have to invest in several things, probably a few hundred € and may gain like 15% or 3kWh capacity and most likely only in the sector above 100 km/h.
So the immediate ROI per one drive would be ~1€ depending on the electricity costs. Meaning, you would have to do these "high-speed" rides at least a few hundred times. If you do so, fine, else forget it.

yep, check the "my main goal" section on previous comments

I am not really interested on improve "economic" efficiency of the car, but the power efficiency to increase the range

at the end I think I will end up spending at least 3-400 eur at minimum, on testing stuff, building things... but still, if I can avoid stopping at all on my trips for me it would really worth it.

 

[pmera91]

Today I went to the local DIY shop, and also I had the idea to use acrylic sheets. I think I will need a way to make custom shapes, but with a mini hacksaw maybe I can do something.
Regarding roof bars:

 

[Spring-zula*161123]

Die Ideen bezüglich einiger machbaren, manuellen aerodynamischen Optimierungen sind aus technischer Sicht immer möglich. Das Grundkonzept dieses vollständig konservativen Karosseriedesign im Windkanal würde wahrscheinlich nur wenig bessere Ergebnisse wie ein Kühlschrank auf Rädern entsprechen...z.B. Mitsubishi L300, alle Fauweh Transporter usw.
Feintuning immer möglich. Die Batterie im hinteren unteren Bodenbereich ist Luftgekühlt ...als Gesamtgehäuse ohne Luft- Zugang/ Abgangströmer, also unbedingt notwendige Verwirbelungen erwünscht...nicht zu vergleichen mit den voll optimierten, vollverkleideten Unterboden mit Thermozirkulation.
Frontmaske mit großen Spalten ohne einer umlaufenden minimalistischen Motorhaubendichtung, dann der "herausragende" Wischerarm mit Umlenkung wird immer für noch ungünstigere Strömungen und Verwirbelungen führen.
Jeglicher Aufwand, eine höhere Effizienz bezüglich der wichtigsten Angriffsfläche, der Frontfläche mit besserem Luftwiderstandsbeiwert herzustellen, ist bestimmt technisch möglich...mit Aufwand,
Viel Erfolg beim Tuning