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Post by Mood Swing Productions on Jul 4, 2006 10:30:50 GMT -6
i do not know many CHILDREN between the ages of 8-12 that have this type of knowledge in physics. i would presume that they have a parent or parents that does or doing the majority of the work for them. to me that doesnt seem very warm and cuddly/father sonish to me. perhaps i am just to ignorant to see this though. WIRL and PDDR race in just a couple weeks. lets see how your 80$ book does.
to quote Nike: Just Do It
the textual boasting and bravado to me is getting quite boring and old. this board is generally speaking not made of these attributes. its about GOOD FRIENDS and one hand helping another. Not one mans education being used to make others feel inferior or attempt to.
i also wonder if adults here cant understand whats being said how a 8-12 year old will be able to understand the physics classes.
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Post by docjobe on Jul 4, 2006 11:28:42 GMT -6
It was written
> I believe that Loree racing was held to their council rules in order to qualify
It wasn't the folks at the National Race that held them. Why didn't Loree go to the National Race web announcements and find out what the rules were?? It's similar to an arena football team getting trounced in the Superbowl and then complaining that, Gosh, their local rules said that they could only put 8 players on the field. Duh! Does it take a PhD to be able to read the National rules? And you are correct, almost anybody can build a fast car. Even a monkey can drop a marble down the ramp and it will trip the finish timer pretty quickly. If I were so smart, why do I (and my young team member) have to put in hours and hours of effort and testing to get the car performance optimized? And almost every day something new is learned. As I see it, the more the Harry Potter types of approaches to PWD racing lose, then the more the applied physics types win.
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Post by WarpSpeedINC on Jul 4, 2006 11:50:50 GMT -6
Usually people of your intelligence are on the modest side. It seems you don't fit this model!! The worst thing a person that is educated can do, is assume everybody else is stupid. It is even worse to treat them as such. As far as the Rules for the race in question, most cars came from council races just as they came off the track. It sounds that either your council has little or no rules (even less than ours), or you built this car just for this race. As I said earlier, the outcome may have been different had others chose this route. Fortunately for you, they did not, so the competition was marginal, and didn't really showcase your building skills or knowledge. The WIRL/PDDR arena may be the place for you to do so. Only time will tell!! Good Luck!! Warp Speed
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Post by slkrnsntracing on Jul 4, 2006 13:05:32 GMT -6
The WIRL/PDDR arena may be the place for you to do so. Doc, Send one of your cars to the July race. I'm not really smart enough to understand the Harry Potter comment, so we probably are way behind everybody else. We don't even have a track to test and tune our cars on. We do like to compete though, and we would love to compete with you. Phil
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Post by docjobe on Jul 4, 2006 17:52:05 GMT -6
Hey Phil, Warp Speed, Insane in the Derby Thing, Loree Racing and others
Guys, my left rear wheel evidently came off half-way down the ramp. Please let me go back to the starting line and begin this heat again. In other words, please accept my sincerest apologies for my off the wall E = MC2 type comments over the last several posts. I suppose I got defensive when my credentials and abilities were questioned and I felt insulted when my nephew's car was called a "hot rod" in what I thought was a derogatory manner. The truth is I just completed intense chemotherapy and my head is not quite back to normal ( it probably never was) and I am overly sensitive.
Now, re this National Race thing, it was actually just a commemorative undertaking and sort of a staged deal as a backdrop theme to the 75th Cub anniversary celebration at scout headquarters. I tried to get them to use more restrictive rules to no avail. So a lot of adults were going all out with their kid's cars with what they knew about increasing performance-all with various results-I was as surprised as anyone when our entry won by such a large margin.
In no way are any of you stupid, that adjective would seem to better describe me for coming across as someone who felt you were. Please consider my pompous butt kicked good and hard.
What I am trying to do is become a "consumer's report" type lab that tests Website based PWD accessories according to good testing procedures and methods and publishing the results for all to see as a series of lectures. There are a lot of PWD product suppliers out there that make claims not backed up with data yet they are making profit from gullible kids and parents on top of propagating bad science. Such claims are based on superstition and I guess magic so I just call them Harry Potter. I get so tired of seeing stuff like "Round Wheels Go Faster".
I am sorry that dang book costs 80 bucks but its like a college textbook (and may end up one). It is just like a fine PWD car, you want it to be nice because it is the result of a heck of a lot of work. Now several on this forum have it and we will see if it helps track times.
I would like to compete as well but will be gone a lot in July for tests at MD Anderson Cancer Center. Don't think I could have a car ready by racetime but will work on it later. I have raced so much in the past now I had rather do my favorite things which are teach, test, and write but I'll eventually get a car in so you guys will accept me.
Again, I am sincerely sorry and hope you will allow me to learn from you.
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Post by Smokinjoesracing on Jul 4, 2006 18:00:41 GMT -6
You'll be in our thoughts. It takes a big man to admit they made a mistake. I hope you get a chance to join us in race in the near future. By the way I go to the zoo each month to rub my car on the monkey's butt. I have no scientific evidence as to why...but it has shaved .025 seconds off my time ;D
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Post by slkrnsntracing on Jul 4, 2006 18:59:55 GMT -6
Doc,
No apologies necessary. Sorry if I came across wrong to you. We are all just guys who love to race and compete. Competition doesn't bother anybody who truly loves their sport, it just forces them to be better. We are interested in racing against the best in the sport. I am sure you would fit in well.
I will include you in my daily prayers, along with several others on this board. A lot of us use this board, WIRL, & PDDR to briefly escape family health problems. I know the guys on this board have helped me through several rough times with my kids health problems, and I will always appreciate them.
I still urge you to send a car in when you can. It will help divert your attention away from your problems for a little while. On race night most of us guys wouldn't even know it if we passed a kidney stone.
May God bless you and we'll be praying for good results on your tests in July.
Phil
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Post by Smokinjoesracing on Jul 4, 2006 21:31:01 GMT -6
Phil is correct. You will find a sympathetic ear or two here. Lots of us, self included, have recieved random acts of kindness from others on the board. It is a good distraction when you are worried about loved ones in peril. You won't meet a kinder bunch of people who want to kick your butt on the track ;
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Post by kayjon on Jul 4, 2006 22:44:13 GMT -6
docjobe, First I wish you and your family well wishes and strength for a speedy recovery while you deal with your health issue.
hot rod also hot-rod n. Slang An automobile that has been rebuilt or modified to increase its speed and acceleration
(By calling your nephews car a "hotrod" I was not being derogatory, I was offering high praise for a tricked out car)
My sons car was in fact built to be legal for the council rules provided. Specifically when it came to wheels and axles. When my son was in scouting I always tried to be cautious when looking for loop holes in the rules because when a little boy puts his heart and soul into his race car I never wanted to have to be the Dad who had to try to explain to his boy why his car was disqualified and after all the effort the car could not race, and on race day I did not want to be the type of dad who had to do battle with a judge because" the rules did not say you couldn't, therefore it must be legal"
When we were lucky enough to have won the council race, at the conclusion of the event we were allowed to take a picture of the car and then the council rep placed the car in a shoebox and that was the last we saw of it. There was no more tweaking the car it was confiscated.
Again I wish to congratulate your nephew on a great win and a great honor.
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Post by pddr on Jul 5, 2006 16:48:56 GMT -6
Hey Phil, Warp Speed, Insane in the Derby Thing, Loree Racing and others Guys, my left rear wheel evidently came off half-way down the ramp. Please let me go back to the starting line and begin this heat again. In other words, please accept my sincerest apologies for my off the wall E = MC2 type comments over the last several posts. I suppose I got defensive when my credentials and abilities were questioned and I felt insulted when my nephew's car was called a "hot rod" in what I thought was a derogatory manner. The truth is I just completed intense chemotherapy and my head is not quite back to normal ( it probably never was) and I am overly sensitive. Now, re this National Race thing, it was actually just a commemorative undertaking and sort of a staged deal as a backdrop theme to the 75th Cub anniversary celebration at scout headquarters. I tried to get them to use more restrictive rules to no avail. So a lot of adults were going all out with their kid's cars with what they knew about increasing performance-all with various results-I was as surprised as anyone when our entry won by such a large margin. In no way are any of you stupid, that adjective would seem to better describe me for coming across as someone who felt you were. Please consider my pompous butt kicked good and hard. What I am trying to do is become a "consumer's report" type lab that tests Website based PWD accessories according to good testing procedures and methods and publishing the results for all to see as a series of lectures. There are a lot of PWD product suppliers out there that make claims not backed up with data yet they are making profit from gullible kids and parents on top of propagating bad science. Such claims are based on superstition and I guess magic so I just call them Harry Potter. I get so tired of seeing stuff like "Round Wheels Go Faster". I am sorry that dang book costs 80 bucks but its like a college textbook (and may end up one). It is just like a fine PWD car, you want it to be nice because it is the result of a heck of a lot of work. Now several on this forum have it and we will see if it helps track times. I would like to compete as well but will be gone a lot in July for tests at MD Anderson Cancer Center. Don't think I could have a car ready by racetime but will work on it later. I have raced so much in the past now I had rather do my favorite things which are teach, test, and write but I'll eventually get a car in so you guys will accept me. Again, I am sincerely sorry and hope you will allow me to learn from you. Hey just to let you know you do not need a new car to race at PDDR. you must have an old car that has been tested along with your book to prove your theories. please send one in for our July race. We would love to have ya... mod or stock... ;D I think my brother has sent you the info... our prayers will be with you and your family... Thanks Glenn 2fast4u
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Post by slkrnsntracing on Jul 5, 2006 19:12:20 GMT -6
By the way I go to the zoo each month to rub my car on the monkey's butt. I have no scientific evidence as to why...but it has shaved .025 seconds off my time ;D [img src="http://img.villagephotos.com/p/2005-9/1084256/monkey_logo[1].jpg"] Smokin', I think I found the monkey you've been using. You're about to wear him out. Phil
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Post by Smokinjoesracing on Jul 6, 2006 13:10:33 GMT -6
Shoot! Now Phil is gonna be faster too.
Phil...that's just a lower drag coeficient Monkey's butt!
Moody...How did you know his name was Spanks ?
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Post by docjobe on Jul 6, 2006 13:49:39 GMT -6
Thanks Kayjohn and Glen for your kind words
Please don't take any of the below data/calculation results as trying to be over your heads. To me designing a car and predicting its performance are much more rewarding than actually putting it together and seeing how it does through a lot of trial and error.
I am in my 70s now and my hand/eye skills ain't what they used to be. But I would like to get involved in WIRL in some fashion. I have now had time to review some of what you guys are doing and I am pretty impressed. I pushed my cars in the old days to constraint limits as set by the Sam Houston Council. After our (son's) car won by 6 car lengths (but with small axle/bores etc). And they threatened to bar us from racing. So they allowed me to set up a rules committee. But also what I have is designs applicable to the Stocks and Mod types you guys are racing.
The designs I have aren't "theories" but rather simulations with the same physics that are used and proven every day from aircraft to large gravity driven cars. I have in the past built 26 different car types and measured their actual times and compared them with simulations.
Now to start this off on the right foot I would like for Smokin'Joe'sRacing to realize I have a lot of trouble building a simulator to model the effects of a Monkey's butt. So I'm guessing that effect is one to also be considered as pure theory
Regarding the WIRL racing, in real life you can get close to a Perfect Race, one where there is negligible center strip rubbing and the car goes from start to finish along a line marked by the intersection of a vertical plane with the track surface parallel to the center guide strip. If you run about 20 heats on a good level (lateral) track, sometimes you get one close to a Perfect Race heat like the 2.9471 s heat that the Barga Family just turned in. Now, consider a Perfect Car. It has no air drag, no friction, zero energy used in wheel rotation, and its Center of Mass position (CM) is set to match whatever CM the real car has to which you are comparing times. For the WIRL Best Track measurements, and considering the g factor in Marietta as close to 979.27, the Perfect Car running a Perfect Race (or heat) is likely close to 2.9152 s. Thus there is about 0.0319 s on the table. Nature will let us have some of it.
I have looked at the photographs of some of the fast mod cars and can estimate body frontal area and drag coefficient. At low PWD speeds the amount of surface area determines a good part of the drag (Lecture 8,9), so minimizing this and using a weighted airfoil at the rear and a light wooden airfoil at the front (with very little surface area in between) can gain you about 0.0076 s in time reduction from air drag reduction alone.
Probably the Barga Family mod car used a Delrin RS racing wheel type ( 3.05 cm dia) with the bore reduced to about 0.026" by various techniques running a hardened steel 0.024" axle. Of course 1 front wheel is elevated not to touch the track surface. Assuming a good lubricant you can get a coefficient of friction of about 0.06. With this bore diameter and friction coeff the optimum diameter of the wheel is reduced to about 2.4 cm. This is because more diameter will be slower because of increased wheel moment of inertia and less diameter will be slower because you are reducing wheel bore radius/wheel radius lever advantage. The optimum diameter is pretty flat so that there is little difference from 22 to 26 mm. So go to say 25.4 mm = 1" so you can still have 3/8" bottom clearance.These wheels should make you 0.0050 s faster.
So far I we have a total 0.0130 seconds improvement so pehaps the Barga car, (or someone else) could get a heat of 2.9471 - 0.0130 = 2.9341 s (monkey butt effects not included)
There may be another mod that will give another 0.0100 s improvement but I am not sure it will pass inspection and it would pose some real construction challenges.
Regarding the 0.025" axles, you could go to 0.020" or No 76 drill bit shaft size. But when the little car hits the 41" curved transition section at 11 mph it starts pulling almost 1.9 g's. That's almost doubling the weight force on the rear axles so during stationary testing might be wise to add a few ounces to the rear to see if the axles would hold it
Where this race is headed is interesting and I am just now looking into it. The race reminds me of that ancient Greek fellow who proposed that there is no sense in running a race because no matter how fast you were you could never quite reach the finish line. For if you ran halfway to the finish line you still would have halfway to go. And when you covered half that distance you still had half of it remaining. So you would tally up 1/2, 1/4, 1/8, 1/16, 1/32, which keeps going on forever so you never quite get to the finish. Now his argument has faulty logic, but according to physics the Perfect Race (heat) time on the Perfect track is the ultimate limit. Unfortunately, because of the uncertainities introduced by things like timer noise and imperfect tracking, as your mod cars get closer to this ultimate time, the heat times will start to overlap considerably and the averages will begin to jump back and forth just short of the ultimate time in a random fashion. So it will be kind of like rolling dice to see who wins the event.
But there are plenty of other ways to keep it lively. For example the Piontidosi type near circular arc ramp really lets you play with the CM effect ( Lecture 7) which is 4 or 5 times larger than on the Best Track. And you don't get the large g force on the rather sudden transition curve of the Best Track that could bend small axles. And also outlawing small axles/bores on the Stock cars will really make friction go back to lubrication ability rather than how small you can get the axle/bores.
Thanks for listening. Hope the ideas will start some interesting mods.
PS I will be in the hospital tomorrow for checkups and am optimistic so thanks for all the well wishes.
Doc Jobe
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Post by builderjim on Jul 6, 2006 14:54:15 GMT -6
Regarding the WIRL racing, in real life you can get close to a Perfect Race, one where there is negligible center strip rubbing and the car goes from start to finish along a line marked by the intersection of a vertical plane with the track surface parallel to the center guide strip. If you run about 20 heats on a good level (lateral) track, sometimes you get one close to a Perfect Race heat like the 2.9471 s heat that the Barga Family just turned in. Now, consider a Perfect Car. It has no air drag, no friction, zero energy used in wheel rotation, and its Center of Mass position (CM) is set to match whatever CM the real car has to which you are comparing times. For the WIRL Best Track measurements, and considering the g factor in Marietta as close to 979.27, the Perfect Car running a Perfect Race (or heat) is likely close to 2.9152 s. Thus there is about 0.0319 s on the table. Nature will let us have some of it. Probably the Barga Family mod car used a Delrin RS racing wheel type ( 3.05 cm dia) with the bore reduced to about 0.026" by various techniques running a hardened steel 0.024" axle. Of course 1 front wheel is elevated not to touch the track surface. Assuming a good lubricant you can get a coefficient of friction of about 0.06. With this bore diameter and friction coeff the optimum diameter of the wheel is reduced to about 2.4 cm. This is because more diameter will be slower because of increased wheel moment of inertia and less diameter will be slower because you are reducing wheel bore radius/wheel radius lever advantage. The optimum diameter is pretty flat so that there is little difference from 22 to 26 mm. So go to say 25.4 mm = 1" so you can still have 3/8" bottom clearance.These wheels should make you 0.0050 s faster. So far I we have a total 0.0130 seconds improvement so pehaps the Barga car, (or someone else) could get a heat of 2.9471 - 0.0130 = 2.9341 s (monkey butt effects not included) Consider this, Barga ran a 2.925 s run in Utah. Although the g factor is different, the track is the same dimensions. Way to get to that Perfect RUN Barga. Jim
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Post by Mood Swing Productions on Jul 6, 2006 16:32:42 GMT -6
well it is only July 6th right now. the race is not until July 22nd. priority mail is 3 day mail and there is next day air as well. you have easily 10-12 days to get one of your proven cars bubble wrapped, boxed, form filled out and shipped to WIRL. we love watching the videos so we will highly anticipate seeing your car or cars perform!! you have described them so well as to how they are ready to race the speed, so get them in so we can all learn!!
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hotrod
Head in the Pine
Posts: 136
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Post by hotrod on Jul 6, 2006 17:11:44 GMT -6
Dr. Jobe, thanks for your insight and we look forward to seeing one of your cars in GA. Hope things go well for you with your tests . good luck!! Ed Half Moon Racing
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Post by Smokinjoesracing on Jul 6, 2006 18:34:07 GMT -6
Doc,
It only works in the Summer months...They put the monkeys inside during the winter. ;D
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Post by 2FAST4U on Jul 20, 2006 21:39:51 GMT -6
Jul 6, 2006, 1:49pm, docjobe wrote:Thanks Kayjohn and Glen for your kind words Regarding the WIRL racing, in real life you can get close to a Perfect Race, one where there is negligible center strip rubbing and the car goes from start to finish along a line marked by the intersection of a vertical plane with the track surface parallel to the center guide strip. If you run about 20 heats on a good level (lateral) track, sometimes you get one close to a Perfect Race heat like the 2.9471 s heat that the Barga Family just turned in. Now, consider a Perfect Car. It has no air drag, no friction, zero energy used in wheel rotation, and its Center of Mass position (CM) is set to match whatever CM the real car has to which you are comparing times. For the WIRL Best Track measurements, and considering the g factor in Marietta as close to 979.27, the Perfect Car running a Perfect Race (or heat) is likely close to 2.9152 s. Thus there is about 0.0319 s on the table. Nature will let us have some of it. Doc Jobe So I am just wondering a perfect pass on a best track at wirls dimensions is 2.915's can a car go any faster than this time... if so how much faster if any or is this the perfect pass stay tuned... ;D
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Post by JOKER on Jul 20, 2006 23:33:30 GMT -6
So I am just wondering a perfect pass on a best track at wirls dimensions is 2.915's can a car go any faster than this time... if so how much faster if any or is this the perfect pass stay tuned... ;D 2FAST4U, DO YOU HAVE A MONKEY IN YOUR BASEMENT? ;D HAVE YOU, PHIL, & SMOKIN' BEEN TRADING SPEED SECRETS AGAIN?
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Post by Barga Racing on Jul 21, 2006 8:16:59 GMT -6
Glenn, I believe Doc stated the perfect pass on Wirl's track would be a 2.9152 considering the affect of the G factor in Marietta. I am no physics guy and I don't know how to calculate G factor or timer affects or anything else like that but considering elevation above sea level and atmosheric density would probably have an affect on times, even on the same length track with the same timer. I don't know the exact dimensions of Larry's track at Lima but I do remember that D&M made a 2.90?? and 2.91?? pass. So I would guess that a perfect pass on that track would be around 2.87 - 2.88. Just my 2 cents.
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