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Old 12-20-2005, 04:29 PM   #16
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Originally Posted by jhigga15
wild...some very good points, but how come Nitro dose not use dish? It seems that the rims need to be stronger there b/c of the weight and speeds and time of the races.
Most nitro cars use ball end suspenstion. So to adjust camber and toe-in, you must stick a wrench through the rims to make the adjustment. Otherwise, if you have dish wheels, you must make a hole, (looks funny), however you can cover the hole with a sticker in between adjustments.(still looks funny)
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Old 12-20-2005, 04:37 PM   #17
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Originally Posted by TryHard

.......Now there would also be an aerodynamic effect, but given that you can't shrink air, it's hardly noticeable, even for a pro (i.e. not me ).........

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If you believe in that comment, then why don't you show up to your next race in an H2 Hummer body while everyone else run the Mazda 6?
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Old 12-20-2005, 08:34 PM   #18
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Originally Posted by YR4Dude
If you believe in that comment, then why don't you show up to your next race in an H2 Hummer body while everyone else run the Mazda 6?

Within reason of course. Don't get me started on scale aerodynamics and just how much it matters on a 1/10th scale RC car.
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Old 12-21-2005, 03:32 AM   #19
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Bizzarely I'm actually going to agree with Soviet on this one!
On a macro scale (ie the whole shell) aero does make a difference, however on the smaller scale (ie the wheels/wings) there is less of a difference, as you simply can't shrink air like you can a component... something to support that is the reason why we don't use aerofoil sections for our wings...
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Old 12-21-2005, 03:35 AM   #20
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Quote:
Originally Posted by YR4Dude
If you believe in that comment, then why don't you show up to your next race in an H2 Hummer body while everyone else run the Mazda 6?
i think his talking about an aerodynamic affect of the dish rims compared to spoke rims
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Old 12-21-2005, 04:20 AM   #21
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Quote:
Originally Posted by 180sx
i think his talking about an aerodynamic affect of the dish rims compared to spoke rims
.. which are even smaller than the bodies and are not exposed to any direct airflow anyway

on the other hand i had some HPI wheels (i guess those were "mesh" type) which were actually creating messy airflow (and noise) through them when spinned at full throttle. At ~3,5-4krpm of their spinning speed this may create some minor losses but it wouldn't be crucial anyway

there are some people who claim that dish wheels are helpful with keeping lower pressure under the body but i'd like to test this in some lab myself before believing that there is any serious difference between wheels causing influence on laptimes.

And the good driver is always a good driver no matter what rims he's using.
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Old 12-21-2005, 08:53 AM   #22
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Here's my take on this issue...

If you consider that a dish and a spoked rim both have the same weight/mass, then the spoked one usually will have more strength...

Here is my theory...
Lets consider that the dish rim is like a piece of metal plate and the spoked rim is an I beam where both has the same weight/mass of the same metal. It sure would be a lot easier to bend the metal plate than trying to bend the I beam.

Some would say that a dish rim also has ribs for support, yes but a spoked rim can have thicker ribs than a dish rim since it has more plastic to use if both rims uses the same amount of plastic. So for the same weight, you will have a stronger spoked rim over a dish rim and since tire and rim weight are so important (rotating mass) I would choose spokes anyday! Plus they look way cooler than dish... ughhhh.... When have you seen a racing sedan use dish rims??? As for aerodynamics, I would say it is too minor to be effective, if it worked even in real scale, they would have used it in Formula 1 where aerodynamics is one of the main factors. The only place I've seen dish rims used is in cycling, but I heard they only use it for speed runs cause they steer real bad!
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Old 12-21-2005, 08:56 AM   #23
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Quote:
Originally Posted by Lokanas
And the good driver is always a good driver no matter what rims he's using.

I agree with that...
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Old 12-21-2005, 10:49 AM   #24
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Quote:
Originally Posted by TryHard
.....
On a macro scale (ie the whole shell) aero does make a difference, however on the smaller scale (ie the wheels/wings) there is less of a difference, as you simply can't shrink air like you can a component....
Not to pick on you. But lets talk about this further. Given what you said about macro vs. micro then does that mean there is no difference among sedan bodies of relatively the same shape?

So a Protoform Mazda 6 is the same as a Dodge Stratus 2.0 & 3.0 and also the Nemesis and CTS? As well as the Losi Alfa, the Losi Skoda? And all other sedan bodies like the Ride TSX and so on... In other words there are no aerodynamic differences among them because the differences are minor (ie micro). Hence any body will do.

Lets talk about that. BTW some bodies are stiffer than others, so lets weight that factor into the discussion.
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Old 12-21-2005, 11:04 AM   #25
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Quote:
Originally Posted by YR4Dude
Not to pick on you. But lets talk about this further. Given what you said about macro vs. micro then does that mean there is no difference among sedan bodies of relatively the same shape?

So a Protoform Mazda 6 is the same as a Dodge Stratus 2.0 & 3.0 and also the Nemesis and CTS? As well as the Losi Alfa, the Losi Skoda? And all other sedan bodies like the Ride TSX and so on... In other words there are no aerodynamic differences among them because the differences are minor (ie micro). Hence any body will do.

Lets talk about that. BTW some bodies are stiffer than others, so lets weight that factor into the discussion.
Please lets not...
They believe that all TC bodies....at least the simular style ones.........LOL
Funny, my car can enter corners faster with a Ride Accord than with a Mazda 6 with the same setup. A Yokomo E Stratus turns in even faster. It has more to do with the rear deck length. So to say that these bodies don't have different handling charactoristics is hog wash.
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Old 12-21-2005, 11:22 AM   #26
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Quote:
Originally Posted by RC Robin Hood
When have you seen a racing sedan use dish rims???
Come on, get real Any racing car has one seriously big problem spinning inside the rim - the BRAKE ROTORS They need serious airflow. Many racing rims are done with keeping heat dissipation in mind as well, so any full scale car will never use closed dish design. Any engineer would chose much better brakes instead of a bit better aerodynamics.
And "something like dish" was done many times - old rally-winning Lancia Delta HF Integrale had them, 1977 BMW M1 had something like them and so on and so on..

Anyway, this discussion is nothing without proper lab testing.. And the lab testing is nothing compared to real laptimes So i guess it's worth using whatever you want if you can go faster with it.. Even if the reason is only psychological
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Old 12-21-2005, 11:41 AM   #27
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There are simple physics involved. If you take a dish and a rim of equal weight and diameter, the dish takes less force to move. That's proven by science.



Not sure how much of an effect that has on our level.

I would imagine that with a dish, the mold would be cheaper making the wheels cheaper. Also, since the molds are simplier, it would be easier to make a "true" precise wheel out of a dish design.
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Old 12-21-2005, 01:29 PM   #28
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Quote:
Originally Posted by YR4Dude
Not to pick on you. But lets talk about this further. Given what you said about macro vs. micro then does that mean there is no difference among sedan bodies of relatively the same shape?

So a Protoform Mazda 6 is the same as a Dodge Stratus 2.0 & 3.0 and also the Nemesis and CTS? As well as the Losi Alfa, the Losi Skoda? And all other sedan bodies like the Ride TSX and so on... In other words there are no aerodynamic differences among them because the differences are minor (ie micro). Hence any body will do.

Lets talk about that. BTW some bodies are stiffer than others, so lets weight that factor into the discussion.

In essence...yes. As long as the bodies are the same generic shape with the same rear wing area, the aerodynamic differences are negligable. The only problem is that people WANT to believe that say a Parma Alpha is so much better than say a Mazda 6 or even an HPI Alpha for that matter.

It's all a bunch of snakeoil and hooey marketing to ensure that the brainwashed RC masses consume the latest and greatest lexan shell.

And almost everyone disagrees with me. But I don't care because I'm right.
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Old 12-21-2005, 01:52 PM   #29
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Quote:
Originally Posted by Soviet
In essence...yes. As long as the bodies are the same generic shape with the same rear wing area, the aerodynamic differences are negligable. The only problem is that people WANT to believe that say a Parma Alpha is so much better than say a Mazda 6 or even an HPI Alpha for that matter.

It's all a bunch of snakeoil and hooey marketing to ensure that the brainwashed RC masses consume the latest and greatest lexan shell.

And almost everyone disagrees with me. But I don't care because I'm right.

A mazda 6 and a Parma ALFA handle completely differently and have a vastly different shape. Now a LOSI Alfa is different than a PARMA, which is different than a PROTOFORM. See, someone can tell me they don't feel different, but PHYSICS says they will, and oddly, physics doesn't lie. So if they make no difference to you then your car is too slow to exploit the differences.

You don't have to shrink air, air is a constant force, and the bodies we run make downforce in varying degrees, Some one needs a wind tunnel to prove the naysayers that these things really do make a difference. At 10 MPH it's not a whole lot, so if your cars that slow it won't make a difference, but at 35 mph your TC's punching a bigger hole in the air than you realize, and that air has to flow around the body.

You don't care because you can't tell the difference, and therefore you think you're right.
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Old 12-21-2005, 02:14 PM   #30
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Soviet...stick your hand out of your car window at 30-35 mph and tell me there isn't a very strong force from the air against it. If it's strong enough to influence your hand then it'll certainly do the same for an R/C car...especially one with a body designed to take advantage of air as a fluid.
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