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Wheels & Times ?
- Thread starter Momentum Racing
- Start date
- Nov 24, 2011
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Momentum Racing said:
Ok... when I get home after work tonight I will pull out 2nd Hand Smoke, take a picture of the weight placement and post it for you and everyone to see, even though it won't help you on cars, because you are failing to understand that every car is not the same and every builder has a different skill set level and methods on how they build a car. While the basic principles of how you build a car can be applied to every build, actually prepping, weighting and then tuning that car to make it into a contending car takes time and lots of learning and experience from racing.
Frankly, if I were Kinser, JBD, Hurricrane or any of the top racers and vendors that that came before us, who spent time and money and developed all of the technology and products and methods of building cars we all use, to hear you say that you can build a car equal to theirs from a few step-by-step instuctions, I'd be a bit cranked off by that statement. DD4H put out a DVD giving us all his oil tips, and here we all are still trying to master them. Spacewalker on his site has a ton of videos showing how he builds cars, and here we all are trying to catch him. Then a moment later you say that your cars are a "good .025 or more behind the better times", so maybe your PWD derby building and tuning skills are not as good as you think they are.
All I can say to you is lets see these cars that you can build that are equal to the top racers who have won and know what they are talking about when comes to building and racing PWD cars.
Again, I look forward to racing with during the Man of the Mountain series. Its time to move onto more productive PWD subjects.
Steve - Mister B
- Nov 24, 2011
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Challenge accepted!Kinser said:
Ha! I beat you! My car has *infinity* drift! /images/boards/smilies/eek.gif Wait, comparing the wrong variable...TX Chemist said:
Actually, I have been gnawing on how much speed difference there is with minute changes in the vertical weight placement.
A CoM that is 1/4" lower than another (no friction, everything else being exactly the same) will result in the lower weighted car winning by 0.0005s (manual calculation to 4 decimals), or 0.00043s (using Excel).
Long, convoluted story of maths and assumptions:
- Ramp angle = 27.1°
- Minimum start height of weight: 48" (weight hovering frictionlessly at track's surface)
- The flat of the track: 389"
- Fall distance (vertical) of weight: 48" + (cos(27.1°) * h1) - h1
- Acceleration down ramp: g*sin(27.1°) = 32.174 ft/s2 * 12 in/ft * sin(27.1°)
- v = sqrt(2*a*d)
- s = d/v
- =389/(SQRT(2*32.174*12*SIN(27.1)*(48+SIN(27.1)*h1-h1)))
| +Height | Slower |
| 0" | 0 |
| 1/64" | 0.0000266s |
| 1/32" | 0.0000531s |
| 1/16" | 0.0001062s |
| 1/8" | 0.0002125s |
| 1/4" | 0.0004251s |
(Just like I shouldn't have spent so much time calculating this mess. /images/boards/smilies/redface.gif)
(Edit: Dangit. Excel "fixed" my equation for me, and gave me bad answers. Corrected times and equation.)
Kinser Racing said:
Chris, I apologize, some things just set me off, but I'm done with that now!
- Nov 24, 2011
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Vitamin K
Guest
I have never quite understood folks that lament that a thread is getting too wordy...by adding more posts to said thread. If it's not useful to you anymore, ignore it. /images/boards/smilies/smile.gif
Crash Enburn said:
Very good information. /images/boards/smilies/thumb.gif
Could you run the same test comparing the weight placements of a 6|6|Axle|6|6-front > configuration, to say a 6|6|axle|6|4|2-front> configuration ? ....I would love to see the difference in potential speed gains.
Momentum said:
Thanks. I hope it can help someone some time.
Not a test. Just math. No aero, no friction, no calculus. Just an imaginary, perfect-world 42' track with a 27.1° slope that a car goes down and then continues onto the flat undisturbed...Momentum said:
Crash Enburn said:
Yes I understand, all values are derived in a perfect world vacuum, but I would love to see the difference in potential, even though it may never apply to real world results. In fact, It will show what I've been trying to convey. The bigger "motor" will be faster on paper, by how much I don't know, but it is guaranteed to be faster. In real world however, it is known that many top racers are not running the biggest motor. Real world can be a real b***h !
It seems to me that so many people place a lot of emphasis on numbers like steer and COM.
I think every car is different and you have to find what it needs to be fast.
The only Numbers that really matter are the ones that show on the timer as compared to everybody else that you are racing in your given class.
I think every car is different and you have to find what it needs to be fast.
The only Numbers that really matter are the ones that show on the timer as compared to everybody else that you are racing in your given class.
- Nov 24, 2011
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Vitamin K said:
It's not the post counts in a thread, it's the rambling on and on and on. But, that's your thing. My thing is to tease you about it. Lol
Kinser Racing said:
Are you saying size matters?.... I've been trying to convince my wife for years it doesn't. /images/boards/smilies/biggrin.gif
- Nov 24, 2011
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Momentum Racing said:
Or, quit over compensating and get to the point./images/boards/smilies/biggrin.gif
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