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Has anyone given any thought to Improving the under-car aerodynamics, particularly in the Sedan?
As a former Citroen owner i am used to seeing a smooth bottom under a car.
Having just bought a Sedan, I noticed the big gap between the spare wheel well and the rear skirt. Has anyone considered filling that space with a sheet of plastic or cardboard to see the difference?
If successful, maybe someone could fabricate fiberglass panel to do the job.
hmm sounds like a good project!! i dont drive my wifes aveo much so i dont kno the aerodynamics yet. but i have been looking to add some strut bars. nice car btw Gclark.
I've heard of a few guys doing this. The results vary depending on the car. Before even thinking about doing the back, I'd make sure there is a pan/tray under the engine bay.
i agree, either front first, or all the underside.
Past experience with a Citroen DS23 required the front underside fairing to be removed above 35 degrees Celsius. This increased airflow through the radiator, thus preventing the car overheating in our 45 degree summer days.
The Aveo 5 door Hatch has a drag coefficient of .36 and .326 for the sedan, with a small amount of streamlining this could be improved. see: 2011 CHEVROLET AVEO 2LT Sedan Automatic data in automobile-catalog.com
Keep the suggestions coming......
Well, if you can't cover up the engine bay, there really is little to no use covering the rear. Once the flow has been disturbed that much, it won't just smooth out over the back.
I am quite surprised to hear you had overheating problems with a bellypan on. There is plenty of space for air to escape out the wheel wells.
Mabe someone with a
ScanGauge II - The 3-in-1 Automotive Computer
http://www.tercelreference.com/downloads/scangauge2.JPG
can do some experiments...
If you compare the CD of the sedan and hatch its the rear end that makes the difference.
I have an UltraGauge stuck in the mail right now, but after a little time with it I intend to try an undertray.
I can see why the ds23 would need the pan removed for heat to escape, it had a cramp engine compartment (iirc it even had the spare tire in there?).
The aveo has a fairly empty engine bay in comparison and a larger grill opening. i would try a belly pan to see if the overheating occurs, i think it would do better. You are in a VERY hot climate though. Is the heat issue even while moving?
I agree there. But, the airflow over the top and sides of the car is attached the whole way from the front to the back. If you put a buncha stuff on your hood to mess up the airflow, the rear end isn't going to matter much.Quote:
Originally Posted by gclark8
I am not having much luck mastering the multi quote feature, so here goes:
FASTRAKR, I must get one of those Automotive Computers and join you in the experiment.
petrified.rabbit, Yes the DS23 had everything under the bonnet, wheel, bipod etc..
Summer days here can be extremely hot, aircon is essential.
It you try a pan under the engine, I suggest monitoring the air pressure near the engine air intake. I would be concerned about starving the motor of air.
Daox, the air over the top must rejoin the air under the bottom, the smoother this happens, the less turbulance and less drag.
It should be pretty easy to not starve the air from the motor. Most of it comes in from the fender/wheel wells and not directly from the engine compartment. Unless you are running an SRI, but that should be cheap enough to switch to cold air.
As for the engine bay air flow, could you not cut vents into the under pan? have them set to let the air out of the engine bay and toward the rear of the car?
I read into this a bit ago. Im in Iraq right now, but when I get back, Im going to custom make a front splitter and skid plate. I did a fair amount of research, and the front splitter increases undercar airspeed, so that would help with the cooling. It also drops the undercar pressure, so it helps with aerodynamics and sticks it to the ground. Just an idea.
Sounds good. I would like to see some splitter designs, maybe 2-3mm alloy under and in front of the skirt.Quote:
Originally Posted by MJP92284
Like this one: http://www.mgf.ultimatemg.com/group2...rodynamics.htm
Have you seen the under-body stuff done by Skoda to improve economy in their small car?
Is a splitter going to work for the Aveo? the way our bumper comes up at the front I would think if we put a splitter/belly pan it might induce lift in the front.
It's the overall path of the car. From the pout where the splitter separates the air to where those two air paths meet would determine lift, since under the car is shorter/faster that over then car. It should produce downward force.
The splitter for efficiency I believe is used to cut turbulence. Which it will help as well.
Yes. A splitter forces air under the car at a much faster pace, and flows extra air above the car. The fast speed of the under car air speed, creates a low pressure zone. added with the incresed pressure on top of the car, and you have a better aerodynamic vehicle
But if you just add a flat plate to the bottom surface of our cars it will be sitting at a 15 degree angle to the ground (roughly). Wouldn't that induce front lift? My understanding is a splitter needs to be parrallel to ground to work so we would need to put some sort spacer front center to bring it down to the level at the front of the wheel well opening.
Did you follow the link above to? The English Fantasy: Smith and Deakin Spoiler fitted
The Carbon Fiber splitter is what I am aiming for, in aluminum, parallel to the ground.
i would probably mount the splitter to the rad support lower cross brace, and not to the bumper. if it is aluminum or carbon fiber, there is no reason that that length would be an issue. and it would be mounted to a flat area of the car.
Might have to look into that Rabbit. I has hoping for full width but that might look ok too.
it could still be full width, just mounted solidly to the rad cross bar, and not the urethane bumper.