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Post by Skippy Kicky on Mar 29, 2017 10:30:36 GMT -5
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Post by micro on Mar 29, 2017 10:41:54 GMT -5
So she is fast enough to retire the other car?? WOW. What are the retaining tubes you are using? I have not seen blue before.
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Post by Skippy Kicky on Mar 29, 2017 12:10:49 GMT -5
I'll be working on KOACH trying to get it up to speed, but yes, this car is a couple thousandths faster. I hope it does well in traffic. Those blue retainers are pretty sweet! They stay in place real nice and don't scrunch up like some of the silicone retainers. I'm actually not sure what they are made of. They came with my solid rear axles from John. Im definantly going to try to purchase more. If it comes in different colors that would be fun as well.
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Post by 3171scott on Mar 29, 2017 15:29:43 GMT -5
Verry Nice...Good luck!!
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Post by 3171scott on Apr 13, 2017 11:20:27 GMT -5
Its very interesting to see on the unlimited cars that the wheelbase has shortened up the last couple of years now. Im guessing that this allows for the desired weight on the DFW. I have even noticed that in the other classes that the wheelbase has shortened.
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Post by The Zeebzob on Apr 13, 2017 11:26:26 GMT -5
Its very interesting to see on the unlimited cars that the wheelbase has shortened up the last couple of years now. Im guessing that this allows for the desired weight on the DFW. I have even noticed that in the other classes that the wheelbase has shortened. It actually gives you longer hill time. |
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Post by 3171scott on Apr 13, 2017 11:31:32 GMT -5
sorry for the double post.
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Post by 3171scott on Apr 13, 2017 11:47:58 GMT -5
Trying to picture it in my head. I completely understand the principle of rear weight creating longer hill time, not seeing in my head, how the front wheels affect hill time. My understanding is that when the car is flat it stops making energy. I did not think the fronts made a difference other than creating a longer more stable stance. Not questioning you Zeeb, or the results, but do you have a picture showing the science? Thanks for the tip!!!
Scott
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Post by The Zeebzob on Apr 13, 2017 11:53:55 GMT -5
Trying to picture it in my head. I completely understand the principle of rear weight creating longer hill time, not seeing in my head, how the front wheels affect hill time. My understanding is that when the car is flat it stops making energy. I did not think the fronts made a difference other than creating a longer more stable stance. Not questioning you Zeeb, or the results, but do you have a picture showing the science? Thanks for the tip!!! Scott The front wheel being farther back will result in the car changing its downward angle a fraction of a millisecond later than if the front wheel was at the very front of the car. |
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Post by Crash Enburn on Apr 13, 2017 11:56:11 GMT -5
I think that what Zeeb's saying is that with the front wheel closer to the rears, it helps condense the weight of the car (so less rotational mass in the transition), and moves the CoM backwards fractionally, too — CoM further back, more potential energy.
Hmm. This gets me to thinking... Having the weight lower is better than high, and moving the front wheels back helps in weight placement, too, it would seem that if one were to do a 45° NDFW, it would be better to have it *under* the car instead of on top. I wonder if that would fit. And it would be placing a Bernoulli bump-out on the right side of the car...
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Post by micro on Apr 13, 2017 12:17:20 GMT -5
If a guy has two cars with different wheelbases, one at 5 inches and one at 4.5 and the steer is both set at 4 inches over 4 feet which car is making more friction on the rail, or is it equal?
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Post by Crash Enburn on Apr 13, 2017 12:41:29 GMT -5
Looking only at friction on the rail, I would think that with some incredibly accurate means of measuring, you would find the 5" wheelbase was providing a micron less friction.
Or is it the other way round? Shorter wheelbase needing less steering angle to move the nose 4"... In either case, I think the difference would be so minute as to be immeasurable. A butterfly fart in the amazon could affect the car equally...
But that car will have a higher angular momentum (more resistance to changing planes in the transition). I'm not sure if that's been tested — angular momentum's effect on a car. It would be an easy test: create a car with wheels at each end, four evenly spaced pockets (two each on either side of the midline), and then two weights. Run the car with the weights in the pockets at the ends. Then run the car with weights in the center pockets. The CoM would be unchanged, but the angular momentum would be.
I need a track. And a basement.
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Post by Professor Moriarty on Apr 13, 2017 17:56:47 GMT -5
Looking only at friction on the rail, I would think that with some incredibly accurate means of measuring, you would find the 5" wheelbase was providing a micron less friction. Or is it the other way round? Shorter wheelbase needing less steering angle to move the nose 4"... In either case, I think the difference would be so minute as to be immeasurable. A butterfly fart in the amazon could affect the car equally... But that car will have a higher angular momentum (more resistance to changing planes in the transition). I'm not sure if that's been tested — angular momentum's effect on a car. It would be an easy test: create a car with wheels at each end, four evenly spaced pockets (two each on either side of the midline), and then two weights. Run the car with the weights in the pockets at the ends. Then run the car with weights in the center pockets. The CoM would be unchanged, but the angular momentum would be.I need a track. And a basement. Hi Crash, I was unable to follow... can you explain this idea another way? Thanks, Edit: Oh... are you still talking about the rotational moment in the bold text? |
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Post by Crash Enburn on Apr 13, 2017 18:06:05 GMT -5
Yes, you got it. Words failed me, so I just ran with "angular momentum".
I would like to know of the effect of the rotational moment on a car's speed. Just like I'm wanting to know about the extra air friction on a Bernoulli car.
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Post by Professor Moriarty on Apr 13, 2017 18:18:54 GMT -5
I think that rotational moment is pretty big. Check out Morgan King... She beat the hell outta Grandpa with a tiny car. link |
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