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Old 12-18-2008, 11:32 PM   #16
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I call bs, have you lost a wing in a final? car is suddenly loose as hell everywhere. You also mean to tell me that aero grip doesn't exist in the dodge viper GTS-R that I prepare at work? LOL
Well if the body lost the wing, that is another story. I believe the big wing (compare with the real car it is relatively much bigger) will have certain effect. But what I said is the body itself (w/o the wing) will not give us much room to think of flow separation, ground effect etc. That is why I said every car body with the same size wing (<--sorry didn't mention that) and same weight will not give people too much difference. But it looks I may be wrong because everybody here seems to be able to tell the difference. Well I may need to do more research...lol
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Old 12-18-2008, 11:43 PM   #17
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If the weight of a body mattered then paint schemes would be opaque mono tone jobs & not these 15 layer jobs that we see on sponsored rides. Weigh your un painted body and then weigh your painted body please. If you don't think that aurodynamics matter then tell me why my stock buggy w/ wing goes 3 mph slower then my stock buggy w/out a wing on it. Aerodynamics makes a huge difference. If you are running mod then you want something that will give you tons of well ballanced down force. If you are running stock then you want it to cut like butter. The weight of your body is all part of balancing your car. Some roll is a good thing.
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Old 12-19-2008, 12:04 AM   #18
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Don't believe any aerodynamic myth. The aero effect will only start to work on your car when you run your car over 40mph. You may run very fast motor so that you can speed your car up to 60mph, but you also need to think about how many corners on the track. Can you turn into a corner in 40 mph? If not then just choose whatever body you like. One thing that you may want to take into account is the weight, the lighter the better. But again if you are not a top racer, you will not be able to feel that few grams difference.
This last weekend I went for a prac' day before a 2 day event and I was taily couldn't figure it out for the life of me. Lift the rear 2mm problem fixed

BTW I had a silver can i it
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Old 12-19-2008, 12:15 AM   #19
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Well if the body lost the wing, that is another story. I believe the big wing (compare with the real car it is relatively much bigger) will have certain effect. But what I said is the body itself (w/o the wing) will not give us much room to think of flow separation, ground effect etc. That is why I said every car body with the same size wing (<--sorry didn't mention that) and same weight will not give people too much difference. But it looks I may be wrong because everybody here seems to be able to tell the difference. Well I may need to do more research...lol
the wing and body are a package, if you look at the wings for different bodies I have yet to see two wings that were the same. Comparing real cars and RC isn't really practical. The wings we use on Real race cars don't work for shit on RC because of the velocities that real wings are designed to work at. Say the GTS-R's Low L /D config, is designed for low drag but at 150mph it supplies about 700lbs of downforce. Right? total car loading is about 2800.... so the wing actually isn't doing all that much work the body produces much of the overall downforce in a sedan type car anyhow. long and the short. RC bodies actually make a fair bit of downforce. For shits and grins, try running timed laps without a body. Its slow as $h!%. anyhow, stop fighting kids. so if you get the balance of the car pretty close. yes body does make a pretty big difference, if your car is crazy loose or crazy tight sure you wont feel it anyhow. try running with the body off like I said and it will shed a bit of light on things. I will try to get some data on body lift this winter just cause I am actually curious what the values are anyhow.
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Old 12-19-2008, 01:52 AM   #20
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the wing and body are a package, if you look at the wings for different bodies I have yet to see two wings that were the same. Comparing real cars and RC isn't really practical. The wings we use on Real race cars don't work for shit on RC because of the velocities that real wings are designed to work at. Say the GTS-R's Low L /D config, is designed for low drag but at 150mph it supplies about 700lbs of downforce. Right? total car loading is about 2800.... so the wing actually isn't doing all that much work the body produces much of the overall downforce in a sedan type car anyhow. long and the short. RC bodies actually make a fair bit of downforce. For shits and grins, try running timed laps without a body. Its slow as $h!%. anyhow, stop fighting kids. so if you get the balance of the car pretty close. yes body does make a pretty big difference, if your car is crazy loose or crazy tight sure you wont feel it anyhow. try running with the body off like I said and it will shed a bit of light on things. I will try to get some data on body lift this winter just cause I am actually curious what the values are anyhow.
Wow..you guys really see the body seriously. Maybe I should correct something. The aero effect will be dramatically generated at high speed(<40 mph in theory), but it does still generate down force or drag at low speed (just not as obvious as high speed). What I curious about is how can you measure the lift of a r/c car? you put the car in the small scale wind tunnel? or using some very sophisticated equipment? or use computer program?Seriously...I may lack knowledge in r/c field..just want to know how you professional racers test the car
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Old 12-19-2008, 02:29 AM   #21
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Wow..you guys really see the body seriously. Maybe I should correct something. The aero effect will be dramatically generated at high speed(<40 mph in theory), but it does still generate down force or drag at low speed (just not as obvious as high speed). What I curious about is how can you measure the lift of a r/c car? you put the car in the small scale wind tunnel? or using some very sophisticated equipment? or use computer program?Seriously...I may lack knowledge in r/c field..just want to know how you professional racers test the car
we have some tunnel time scheduled next month. I was going to see if I could do a mockup and test the little cars while i am there. I can't do a 3d scan or frontal scan so I won't have lift over drag numbers but I should be able to come up with something good. . or the alternate is to rig gram scales, with a known flow velocity you can do some archaic arithmetic and get an idea of the downforce , total and front / rear. big cars involve strain gauges and pressure transducers... and if I ever get enough free time I plan on modeling a Stratus 3.1 with CFD.
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Old 12-19-2008, 02:32 AM   #22
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bodies i've tried and liked (running rubber on med-low grip indoor asphalt):

1. Alex Racing Lexus (gobs of steering)
2. Protoform Speed6
3. Protoform Mazda6 (neutral)
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Old 12-19-2008, 02:54 AM   #23
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I think it's fair to say that RC bodies work mostly through drag rather than the finer points of aerodynamics.

But that is not to say that the bodies don't handle differently, they definitely do. When I first put on a PF Mazda after using a Stratus 3 I could definitely feel the extra steering response.
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Old 12-19-2008, 02:58 AM   #24
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we have some tunnel time scheduled next month. I was going to see if I could do a mockup and test the little cars while i am there. I can't do a 3d scan or frontal scan so I won't have lift over drag numbers but I should be able to come up with something good. . or the alternate is to rig gram scales, with a known flow velocity you can do some archaic arithmetic and get an idea of the downforce , total and front / rear. big cars involve strain gauges and pressure transducers... and if I ever get enough free time I plan on modeling a Stratus 3.1 with CFD.
you are really serious..I didn't know people really put car in the tunnel and measure the aero effect..wow...sounds interesting I may use our small scale tunnel to test my car too next semester. Are you a graduate student?
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Old 12-19-2008, 03:19 AM   #25
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If I put my best body on the car, it wouldnt move...

Wife V1.1 its called

Seriously though as said, the Mazda6 is a good all round shell for carpet or asphalt

I have just gone out and got one a few weeks ago, but havn't had chance to cut it out and spray it up yet.
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Old 12-19-2008, 03:30 AM   #26
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I prefer the Speed 6 shell myself.
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Old 12-19-2008, 03:49 AM   #27
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it looks I may be wrong because everybody here seems to be able to tell the difference. Well I may need to do more research...lol
+1 to research haha :P

seriously though, i can tell the difference between bodies..

i could also tell the difference between the rear bumper heights being raised or lowered (ie. the amount that is cut away under the rear bumper).. very noticable effect even 5mm higher IMHO (has anyone cut a body to the 2009 ROAR and/or Global Body Specs?)...

maybe some ppl dont go looking for the right things?
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Old 12-19-2008, 03:52 AM   #28
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here's my tips..

Stratus - if you're a beginner, maybe dont understand setups very well, or feel your car turns too much or transitions very quickly left to right..

Mazda 6 - intermediates/advanced or when you want some performance with nice quick nimble cornering and not too shabby grip (with the wing mounted as far back as legal)..

-Mark
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Old 12-19-2008, 05:00 AM   #29
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real interesting thread here!
recently i did some well structured doe (design of experiment) tests on my car which was really interesting the body choice was one factor i tried and it turned out to be one of the biggest factors to influence lap times at my track so it is well worth studying.
so is there anyone who has 3d scan data from bodies?
i've got no problem with some cfd analysis time (it's my job) I just don't have the capabilities to do the 3d scan bit.
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Old 12-19-2008, 10:37 AM   #30
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you are really serious..I didn't know people really put car in the tunnel and measure the aero effect..wow...sounds interesting I may use our small scale tunnel to test my car too next semester. Are you a graduate student?
lol, no graduated about 6 years ago lol. I work for a grand am race team now..
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