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Old 01-29-2013, 11:15 AM   #1 (permalink)
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1989 CRX aero mods

The winter of '09- '10 I started looking into how the NASCAR and F1 guys were using Computational Fluid Dynamics in their designs. After studying alot of computer generated model airflow analysis and real time wind tunnel test pictures, it started to become obvious how the air moves around things. An air dam forces the air to go around or over the vehicle. An air dam with a forward facing splitter creates a more concentrated area of recirculating air to form just behind it under the front end creating more down force. I believe it does this two ways, first by creating a lower pressure area and second by catching the air in front and above the splitter. As the speed increases, the mass of air, in that area just ahead of and above increases, exponentially. By properly designing the splitter and dam to transfer the load to the chassis, you now have down force without the drag of a wing. I never tested my design with the forward facing splitter because my operating speed range is right at the bottom of where air pressure begins to increase fuel consumption. Double the speed, air pressure increases 4 times and fuel consumption increases pretty linear with air pressure change. Although the design does increase down force because you can feel the cars handling behavior change after you hit 80 mph. My next post will include a simple materials list for those interested and I will need to get out and shoot some new pictures, as I seem to have lost all of the ones I had, including the ones with the boat tail that really did nothing but draw attention. Yes, the first test run with it, earned me a ticket because the license plate was covered up.


Last edited by coyoteX; 01-29-2013 at 11:20 AM.. Reason: puntuation
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Old 01-29-2013, 02:59 PM   #2 (permalink)
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I'm a bit confused. You're road racing or what?
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Old 01-30-2013, 09:57 AM   #3 (permalink)
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1989 CRX aero mods

Sorry, no I am not racing. I used data generated by the guys who are racing to come up with my design. It is on the shade tree side but works great all the same. I will post pictures as soon as it warms up a little. -8* this a.m.
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Old 01-30-2013, 12:26 PM   #4 (permalink)
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Increased downforce is increased drag. Not what you want for hypermiling.
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Old 01-31-2013, 11:30 AM   #5 (permalink)
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moorecomp,
Yes and no, any movement through the atmosphere causes drag. Managing it is the key. As far as hypermiling goes, would you agree that the best milage you can get with the least effort is what we are all trying to attain?
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Old 01-31-2013, 11:53 AM   #6 (permalink)
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True, but moorecomp has a point. If the vehicle does not need any more downforce, I wouldn't go out of my way to add more. Many sports cars have high drag coefficients as a result of the downforce produced/ required to run 180+ mph. There has been a few discussions about front splitters, I would argue that it is more efficient to redirect the air around the vehicle, than to have it apply force and push down on the splitter. Anytime you have the car push the air, you're adding drag.
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Old 01-31-2013, 01:12 PM   #7 (permalink)
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Yep, as long as you're driving the speed limit there should be no reason to add downforce. Most road cars will naturally produce some lift but it's nowhere near enough to become a problem unless you're out on Bonneville (or looking for a $400 speeding ticket).
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Old 02-02-2013, 10:28 AM   #8 (permalink)
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1989 CRX aero mods

I'm in total agreement. I believe that with the way I caused the air to go around the car, that it both reduces air getting under, creating lift and creates down force at speed. I am going to attempt to post photos of the car with the boat tail and with the other mods.
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Old 02-02-2013, 10:45 AM   #9 (permalink)
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Cool, I'd love to see pictures.
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Old 02-03-2013, 12:14 PM   #10 (permalink)
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coyoteX - I understand you're having trouble posting pics.

Describe the problem here and I or someone will help you out.

Also FYI, see: http://ecomodder.com/forum/showthrea...der-18279.html

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