Thread: Electric Yugo
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Old 03-06-2012, 07:09 PM   #6 (permalink)
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If I can get a basic set-up going where I can test changes scientifically without ruining my equipment I'll start making aerodynamic modifications. The Yugo being as boxy and un-aerodynamic as it is certainly has room for improvement. The cd is horrific, but the frontal area is small, so if I can improve the Cd without increasing the frontal area I should be able to achieve a much smaller CdA leading to better battery life and range.

I would be up for some fairly radical aeromods, even if that means changing body panels, I've done projects with fiberglass before (all be it not body panels) and know people that can help with welding. Unfortunately the front end of the yugo is not only blocky, but it sloped downward directing air directly under the unstreamlined underside, which other than directly into a rotating 26in unaerodynamic wheel is about the worst place for air to go. I don't think that just a simple grill block will give me the results that I'd like. I figure that If I change the Yugo from diverting 50% of the air under the car and 50% over to 90% over/ around the side and 10% under as well as adding a full belly pan(no ICE parts to deal with) and a slight diffuser that should net me a huge aero gain. (now by huge I don't mean 60% or something but it may net me up to a 25% gain) Now 25% may seem unreasonable, but by my logic as per the 65+ efficiency mods, even a simple grill block should give me 5%, a simple belly pan should give me another 5%, and a simple diffuser at just a few degrees should also reduce drag by a few percent. Now, not having ICE parts underneath the car to have to work around should allow me a few more percentage points gained for the belly pan, the same thing would go for the diffuser, and diverting flow cleanly over the top and around the sides, as well as a much smaller amount cleanly underneath should make a fairly large difference aerodynamically. The Yugo is a fairly small car, so adding a short boat tail would also be an option. I figure I could mount it on the hatch, which is already cut towards the front of the car, and as per the template streamline it back a couple of feet, then cut the flow off cleanly. That should give me at least as much gain as a simple short kammback would give, but not as much as a full boat tail, but it wouldn't adversely affect the ability to use the hatch. I have these things modeled in Google sketch-up and I'll post them once I have the image posting privileges.

At the moment I'm only working based off of information from others, which may or may not fit my situation. But if I have some good instrumentation and can do some tuft testing I should be able to significantly reduce the drag for the car. I'm not going for a basjoos-like cd of 0.17 but if I can take it from 0.4 to 0.35 or 0.3 that would be awesome.

I read somewhere on this site that somebody did a study which took an extremely streamlined car like the sunraycer and made the windshield completely vertical doubling the drag from 0.12 to 0.24. Then by angling back the windshield to something like 60 degrees it was down almost to 0.12 again. I'll give the guy who posted it credit as soon as I find who did. I figure that there is a similar effect (probably not as dramatic though) with the very front end of a car. I'd be interested to see a test of angling the front end from completely vertical, leaning back until it hit the angle of the windshield incrementally and seeing what the change in drag would be. Now I'm going to need room for batteries, so I probably won't be able to slope the hood/angle the front all the way to the angle of the windshield, as it may not leave me with enough area to put batteries. I should be able to at least angle it back and smooth the transition a bit. I'll be posting different configurations shortly.
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