Areodynamics

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Areodynamics

Postby rsrdoug » Thu Aug 10, 2017 4:54 am

Anyone have any insight on how to improve the aerodynamics of the car?
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Re: Areodynamics

Postby danstern » Thu Aug 10, 2017 6:44 am

The car will get light at speed, it was built for low drag not downforce as you've obviously noticed. The two obvious things are a front splitter and a tail device (Gurney flap or wing). The problem is that either will look totally out of place. There was a car, in period, with a big wing over the cockpit. It won and was declared illegal.
I've thought about mounting a front plat and bending it forward, but think even that would look odd.
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Re: Areodynamics

Postby EEricson » Thu Aug 10, 2017 6:36 pm

You might try a small air dam under the nose, just where the belly pan transitions to the curved nose part. Maybe 2 1/2 inches. Make it black so it disappears. I might try it on my car, as I've now got frame extensions with big bolts right at that location (to attach a tow bar to).

You block the air under the car you can get a little lower pressure under the front wheels which is just what the doctor ordered. Might make a difference. Totally reversible.
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Re: Areodynamics

Postby RS-60 mark » Fri Aug 11, 2017 12:54 pm

I think the concept has been previously exploited. From Special Editions circa 2005:
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Re: Areodynamics

Postby Carlos G » Fri Aug 11, 2017 12:58 pm

I made one that attached to some tow points that I also made. It's located in the same location that Ericson mentions. It was barely noticeable, visually.
I live in an area with twisty, rough mountain roads and after I plowed my gravel driveway a couple of times with it, I took it off.

If I lived somewhere where I could attain the speeds where it might be beneficial, then maybe I'd put it back on. But If I lived in such a place, full of highways, and people driving around in huge vehicles oblivious of their surroundings, then I wouldn't have this car.
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Re: Areodynamics

Postby danstern » Sat Aug 12, 2017 5:59 am

If you want to understand this stuff and really know all of your options read: COMPETITION CAR AERODYNAMICS by Simon McBeath. He goes through the principles, examples, photos, effects, etc.
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Re: Areodynamics

Postby beck688 » Sat Aug 12, 2017 7:10 am

The car is basically and airfoil - the net result is the there is a negative pressure on the top. Slow down the air on the bottom and the differential is less. Mine gets light at a little over 100 and Chuck B says at 130 the front is barely contacting the track.
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Re: Areodynamics

Postby danstern » Sat Aug 12, 2017 6:51 pm

Actually, if you slow down the air underneath the upward pressure rises. That's the way airfoils, Gurney flaps and splitters work.
Look at the flap on the back of a Corvette Z06. It almost stops the airflow and therefore causes a high pressure area (pushing down).
You want to slow it down on top, speed it up on the bottom. A splitter stalls the air in front and pushes down on the lip.
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Re: Areodynamics

Postby beck688 » Sun Aug 13, 2017 5:34 am

You are right I am old yes I will play the age tag. I even owned a 150 that I circumnavigated the US with - how do wings work duh - I will go back to my caretakers now. So very embarrassed!!!!!!!!!!!!!!!
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Re: Areodynamics

Postby danstern » Sun Aug 13, 2017 10:32 am

No problem. That's why this is a fun friendly site. I've stopped going to forums where half the members are hostile. :)
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Re: Areodynamics

Postby sjgharib » Mon Aug 28, 2017 11:32 am

We jumped straight to downforce, but the original question was more generic...

I definitely think the helmet fairing helps. I had a German graphic of all the different iterations to reduce drag, but I can't seem to find it. Does anyone else have it?

Unfortunately all the other aero tricks will really change the way the car looks - another trick is to add louvers above the front wheels in the fenders, but that would look pretty ugly. Also not sure an under-engine venturi tunnel would be possible, but that's another one.
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Re: Areodynamics

Postby sjgharib » Mon Aug 28, 2017 12:01 pm

found it!
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Re: Areodynamics

Postby DannyP » Tue Aug 29, 2017 4:04 pm

I believe what you want is to make the distance travelled for the air underneath to be longer. Just exactly like an upside-down wing. This forces the air to speed up, as opposed to the air going over the top, to rejoin at the back of the car. Hence, downforce. Bernoulli, smart guy.
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