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Aero Question..........

 
Old 02-11-2010, 05:25 PM
  #91  
wanna911
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Originally Posted by SundayDriver View Post
If your traqmate allows analog channels and has math channels, then you can do this. You need a min of 200Hz sampling or the data will be pretty much garbage. 500Hz is much better and 1 kHz is even more accurate. This is because the height is changing at a very high rate and you need all the data to filter it properly.
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Uhhhh, what?








JK but that sounds beyond my tech level.
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Old 02-11-2010, 05:57 PM
  #92  
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It's beyond your Traqmate's tech level too. I used a Traqmate for a year and found it very helpful but very limited. I did learn that I would make use of the data and that's what convinced me to spend the money for the MoTeC system. (I use 500 Hz sampling for the shocks so I can see things reasonably well)

Unless you are really inventive and handy (like Jack and his ride height sensors), the cost of the data system to optimize the use of the wing costs more than simply buying 3 different wings and figuring out which is best based on lap times.
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Old 02-11-2010, 07:31 PM
  #93  
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Good point.
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Old 02-13-2010, 10:17 AM
  #94  
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Originally Posted by claykos View Post
Get a big *** wing, big *** splitter, try to duct your oil cooler/ radiator openings out the top or the sides of the car

Actually, exiting cooling ducts out the topside of the car doesn't help much with downforce, for a couple reasons. First, air going through a cooler slows down dramatically. For example if your car is going 100 mph, the speed of the air through the cooler might be only 30 mph. You won't get much downforce from diverting air going 30 mph. Second, releasing hot air over the top of the car feeds lower density air to your rear wing, which can decrease downforce. So the net effect of having cooling duct exits out the top of the car can be DECREASED downforce. If you look at how prototype cooling packages are designed, they often go to great lengths to duct cooling air out the sides or back of the car whenever possible.

Scott
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Old 02-13-2010, 11:31 AM
  #95  
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Originally Posted by stownsen914 View Post
Actually, exiting cooling ducts out the topside of the car doesn't help much with downforce, for a couple reasons. First, air going through a cooler slows down dramatically. For example if your car is going 100 mph, the speed of the air through the cooler might be only 30 mph. You won't get much downforce from diverting air going 30 mph. Second, releasing hot air over the top of the car feeds lower density air to your rear wing, which can decrease downforce. So the net effect of having cooling duct exits out the top of the car can be DECREASED downforce. If you look at how prototype cooling packages are designed, they often go to great lengths to duct cooling air out the sides or back of the car whenever possible.

Scott
Going out the sides can be preferable to going out the top - however, going out the sides is often not practical in a production based car and going out the top is preferable to going out the bottom or not ducting at all. A properly designed top exiting center radiator also helps to create downforce because it is directing air upwards. If you think of the car in a control volume sense, any air you can direct upwards through the control volume will help you to create downforce. Many front engines race cars do this such as C5R and C6R corvettes, the old Viper GTSR, the new BMW m3 ALMS cars, and even the new 997 RSR.

See for example:
http://www.allcarwallpapers.com/wall...e-car-4859.jpg

And this is a cool pic
http://images.google.com/imgres?imgu...a%3DG%26um%3D1
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Old 02-13-2010, 01:32 PM
  #96  
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Originally Posted by claykos View Post
Going out the sides can be preferable to going out the top - however, going out the sides is often not practical in a production based car and going out the top is preferable to going out the bottom or not ducting at all. A properly designed top exiting center radiator also helps to create downforce because it is directing air upwards. If you think of the car in a control volume sense, any air you can direct upwards through the control volume will help you to create downforce. Many front engines race cars do this such as C5R and C6R corvettes, the old Viper GTSR, the new BMW m3 ALMS cars, and even the new 997 RSR.
True, many production based cars do it this way. But it's often just the easiest way within the rules to do it, more of a design constraint (due to the layout of a production based car) than the ideal way. If it were really the best way to do it, I'd expect to see prototypes more commonly using that method of ducting, since they have a lot more freedom in designing their cars. But I think these days it's not that common.

Maybe we're saying the same thing ...

Scott
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