Streamlined Citroen ZX

[CitroX]

Good day, ecomodders!

Here is my latest project - Citroen ZX.





This was actually the experimental part of my master thesis. I needed to analyse how drag affects a moving vehicle and how it's aerodynamics could be improved. So here is what I did. Firstly I created a rough model using Autocad.



Then tested it with Autodesk CFD Project Falcon



Then did the modifications and here is the final model



Put it in the CFD and got a Cd of 0.23



NOW here is the interesting experimental part. The build began from the underside. Policarbonate and sheet metal was used



Then the boat tail construction started




Boat tail underside made from textolite


First test run early in the morning


Tuft testing



Covered the rear wheel arches, partially blocked radiator ventilation and covered the fog lights + some final touches. And I give You the final result













The summary

The master thesis was graded as almost perfect. So first mission accomplished. Due to the lack of time and money the detail of this project could have been better.

Currently I've removed all of the mods to adjust the brakes fix the clogged exhaust system and to make the car mechanically sound so to pass the mandatory checkup.

The fuel consumption

Orginal car ABA testing did 31.36mpg @ 56mph (speed limit).

Modified car same road same speed but warmer weather did 49mpg. This mpg increase is very close to the one that was theoretically estimated. Yet currently Citroen without the mods is showing a significant increase in mpg compared with the old testing. This might be due to the exhaust system fix and the warmer weather we are having right now.

Future plans

Make the boat tail shorter and more practical. Connect to the ECU to take control of the fuel mixture.

If you took the time to read this
You are awesome.Feel free to like and share my FB page. http://www.facebook.com/flylowlt

[JRMichler]

Warmer weather definitely improves mileage. My sig line has some numbers.

[CitroX]

I started to put the car back together today. Since I have a bit more time now I can test more modifications individually. But before putting the flat bottom back on I've decided to see what difference in mpg would a front splitter make which I had laying in my garage from a rs fiesta.

[CitroX]

I forgot to add tuft testing of the final model in the first post. Unfortunately the camera focused on the windscreen when we were filming yet the tufts are still visible. The mods did a major difference in airflow.

[AndrzejM]

Nice project! I like it! Do you think that you don;t have trouble because of a boat tail from the cops?

[modproductions]

Hi,

wow you have done a lot of work on this car.

If you want to modify it, I suggest you to make it narrower at the back. It will be better with side wind.

[CitroX]

Originally Posted by AndrzejM

Nice project! I like it! Do you think that you don;t have trouble because of a boat tail from the cops?

It is allowed to have one meter+ of cargo to be sticking out of the car as long as it is secured, marked and not draging or anything

Hi, wow you have done a lot of work on this car.
If you want to modify it, I suggest you to make it narrower at the back. It will be better with side wind.

I will try to redesign it a bit. I'll see what kind of a compromise i can work out. And I want to make the whole thing neater, use less white wrap

[Cd]

You did a fantastic job not only with the car, but with your post here on EM.
All the information is nice and neat and you did all the testing that is usually done and showed your results.

The final results look very much like a factory show car from the 1980s back when good aerodynamics actually brought bragging rights.

[mikeyjd]

Great work and welcome to ecomodder

[CitroX]

Originally Posted by Cd

You did a fantastic job not only with the car, but with your post here on EM.
All the information is nice and neat and you did all the testing that is usually done and showed your results.

The final results look very much like a factory show car from the 1980s back when good aerodynamics actually brought bragging rights.

Wow,I knew that ford sierra was aerodynamic at the time but this prototype is full of 80's goodness. That is some good inspiration for the project and it has the wheel fairings which I would like to install.

Great work and welcome to ecomodder

Thank's Mike