Are the speeds possible?

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ddyke	Are the speeds possible?	Lead	[-]
Posts: 4116 (06/14/09 03:08 PM) The 'Scrap Man' Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Tags : None Are the speeds the guys turned possible? This was a question posed to me. My answer is yes and they are believable. I am not at liberty to give away their clever engineering within the rules but the answer is yes and very believable. What you begin with is the theoretical top end and then say the actual speed must be lower than that unless the know something I don't know or didn't think of. What I did was go with the parts everybody could easily find and figure what the top speed would be. Rod and Tom are clever (very clever men) and nice guys who would not cheat but read the rule book --- which if you go back to the rules post Tom was doing as he kept asking for clarification. Here is what I figured before the event for the theoretical top speed of the stock class. Please correct me if I am wrong but don't say that you feel this can't be. This is a math problem and if your head hurts then don't read further. 1. AXLE SPEED RPMs /Gear Ratio = revolutions of the axle per minute 47000 rpm motor, 23 tooth crown gear, 15 tooth pinion 47000 divided by 1.533 =30652 turns of the axle per minute (TAPM) TAPM times 60 minutes in an hour = turns of the axle per hour (TAPH) 30652 times 60 = 1,839,120 TAPH 2. CIRCUMFERENCE OF TIRE Biggest legal tire I could find Diameter times Pi .875 times 3.1416 = 2.75 inches divided by 12 inches in a foot = .229 feet 3. How many feet in an hour Turns of Axle per hour multiplied by the number of feet per turn 1839120 time .229 = 422998 feet per hour 4. How many miles in an hour? 422998 feet per hour divided by 5280 feet in a mile = miles per hour 80.1 miles per hour is theoretically possible with the parts I know of that fit the rules. What keeps the mile per hour lower than this? Friction (mechanical and aero) Electrical Connection is not perfect Bumpiness of track Length of speed trap. The trap was so long we were getting averages of a long distance. What would make it go higher? Clever engineering by guys like Tom and Rod. Parts that are better than what I found. What did they do in the clever engineering -- you won't get it from me but I was convinced when I saw what Tom (Dyno Tom) was doing. I have seen Rod's engineering before. Are you up to the challenge? Come next year and beat these two Cincinnati area boys at their game. To be the man you have to beat the man. Cicero III. xi. "Through a specious appearance of expediency wrong is often committed in transactions between state and state . . . no cruelty can be expedient; for cruelty is most abhorrent to human nature, whose lead we ought to follow."
Robert Livingston		#1	[-]
Posts: 893 (06/14/09 03:15 PM) Home Racing Guru! Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Uh, was the voltage measured during the run? At the rails in the center of the track? It would be interesting to know what voltage the car motors actual "saw". I have seen supposedly regulated transformers drop the voltage under surprisingly light loads. The max rated RPM of a 46k motor is delivered at exactly zero gcm torque. The torque required to push a car at 100 MPH or so must be higher than zero, due to aero resistance as well as drive train friction and rolling resistance. So, no electric motor will ever rev to max RPM, because max RPM is no-load RPM. Again, this limits the top speed below the theoretical, voltage losses notwithstanding. Rather than hinting about the clever engineering, why not help us out of the dark. Particularly since nothing substantial is at stake. Why should we all try to re-invent the same wheel? Personally, I care less about the competitive aspect than the engineering aspect. Last Edited By: Robert Livingston 06/14/09 03:19 PM. Edited 1 times.
ddyke		#2	[-]
Posts: 4117 (06/14/09 03:22 PM) The 'Scrap Man' Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	We measured the voltage at several point with two commercial transformers powering the thing. I do not know the specs on the power supplies. The secrets are not mine to give away. If they wish to do it then that is fine. I do not feel comfortable telling what Tom did. What people do within the rules is their secret. Ask a NASCAR team what they are doing and see if they answer. If you observe these cars the guys worked on friction and gears. What I listed was my own calculations. Cicero III. xi. "Through a specious appearance of expediency wrong is often committed in transactions between state and state . . . no cruelty can be expedient; for cruelty is most abhorrent to human nature, whose lead we ought to follow."
Robert Livingston		#3	[-]
Posts: 894 (06/14/09 03:25 PM) Home Racing Guru! Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	I think your calculations are fine, no problem. But if we want the LSR to gain some traction as a slot car event, someone has to report on the winning cars. Hopefully this event has nothing to do with NASCAR and will resemble it in no way. When prize money is at stake, it makes sense to be secretive. Since there is nothing at stake here, I'm hoping some of the fast guys will come forward (as they do in the Proxy slot car world where body-off photos of the winning cars are posted). Last Edited By: Robert Livingston 06/14/09 03:28 PM. Edited 1 times.
ddyke		#4	[-]
Posts: 4119 (06/14/09 03:39 PM) The 'Scrap Man' Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Kurt needs to address that -- I was the score keeper and tried to work on timing as my primary concern. This was a learning year for sure. Tom did massive testing on a quarter mile drag strip to make sure he could accelerate that first bit quickly and maintain top speed. My observations were that the fast cars were able to maintain electrical connection very well and did not bounce like some did. I was positioned at the big end of the straight (end) and could see the car coming from close to straight on. Tom in the modified class had very little bounce and was as smooth as silk and Rod was close. Their gear noise was minimal. Some random thoughts that I think come into play. Tires swell at speed and this can increase the diameter. - the top speed Aerodynamics comes into play at these speeds - both cars were very aerodynamic in shape. Motors can have a higher RPM than what is advertised. Cicero III. xi. "Through a specious appearance of expediency wrong is often committed in transactions between state and state . . . no cruelty can be expedient; for cruelty is most abhorrent to human nature, whose lead we ought to follow."
Dyno Tom		#5	[-]
Posts: 18 (06/14/09 03:42 PM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Dan The tire I was running was a little over 1" in dia. They were off a box stock slot car and the wheels were a name brand also. The trick was finding a way to keep the tires on the rims above 30k rpm. After our last pass (the one when we turned up the volts just see what would happen), the tires expanded and did hit the bodywork also there were flats on the tires, I think from stopping. The wheels / tires must have been doing 40k rpm. WOW this was fun, now to start working on next years car. I will post more Monday, Thanks to all and if anyone would like a drum to make a DYNO like the one I had at the race, let me know. The man that made it for me should be able to make more for a small charge. Thanks Dyno Tom
ddyke		#6	[-]
Posts: 4120 (06/14/09 03:50 PM) The 'Scrap Man' Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	My concern here is to probe the theoretical first then the pragmatic. We sent "crap" cars down the track every few runs and the turned virtually the same speeds every time. If the theoretical and the pragmatic are out of line then something is wrong. I am working on an idea for verifying the speeds. The software we used was speedtrp.exe by Daniel Groulx (Trackmate/Trakmate). The OS was Freedos. The compter was a 512 meg of ram Dell running at 2.4 MHZ. The sensors by Brent Carlson. Will we improve this? I have a 3.2 MHZ machine for next time and if I can go higher I will. Cicero III. xi. "Through a specious appearance of expediency wrong is often committed in transactions between state and state . . . no cruelty can be expedient; for cruelty is most abhorrent to human nature, whose lead we ought to follow."
ddyke		#7	[-]
Posts: 4121 (06/14/09 03:52 PM) The 'Scrap Man' Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	I guess Dyno Tom has no secrets. Cool! Cicero III. xi. "Through a specious appearance of expediency wrong is often committed in transactions between state and state . . . no cruelty can be expedient; for cruelty is most abhorrent to human nature, whose lead we ought to follow."
ddyke		#8	[-]
Posts: 4122 (06/14/09 03:54 PM) The 'Scrap Man' Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Tom has a chassis dyno that he made and maybe we can persuade him to post the plans. Cicero III. xi. "Through a specious appearance of expediency wrong is often committed in transactions between state and state . . . no cruelty can be expedient; for cruelty is most abhorrent to human nature, whose lead we ought to follow."
ElSecundo		#9	[-]
Posts: 7912 (06/14/09 04:07 PM) Home Racing Guru! Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Guys, within the rules, it was legal to take an off-the-shelf set of gears, and to bore and sleeve them. Before my gears stripped in testing the day befgore the race, I had a gear ratio with NSR gears of 1:3. Not 3:1 -- 1:3. For every turn of the pinion gear (the gear on the motor), the rear axle turned 3 times. With the NSR 46k motor, if the motor is turning at 46,000 rpm, the rear axle was turning 138,000 rpm -- 9 times higher than normal with a 3:1 ratio. Oh yes, the speeds are possible. I like cottage cheese. That's why I want to try other dwelling cheeses, too. How about studio apartment cheese? Tent cheese? Mobile home cheese? Do not eat mobile home cheese in a tornado. Mitch Hedberg
JetGuy.fastlaneslotcar...		#10	[-]
Posts: 190 (06/14/09 07:29 PM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Here is a parts list of my Mosler: The only non-NSR parts i used was the guide flag (gray racing style), crown gears (23 & 24's), and lexan interior were slot.it. All the rest was NSR based on the EVO Mosler chassis with the long can 46k motor/pod. Braids NSR, Wire NSR, FRT Rims NSR w/zero Grip Tires, Axles NSR, Bushings NSR, NSR Ultra Grip Rear Factory mounted wheels/tires, 15t pinion NSR, Medium Suspension Kit NSR, Round Button Magnet (shimmed), Gulf #9 Body Un-modified with wing and mirrors.
bigmike312		#11	[-]
Posts: 1383 (06/14/09 07:41 PM) Home Racing Guru! Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	I didn't have anything to do with the LSR race but if I did and had been one of the fast guys I wouldn't share any information. Why should I spend my time figuring out how to build a fast car and then tell the competition. I've never been one to tell someone how to beat me. Big Mike Never argue with a fool, they'll drag you down to their level then beat you with experience.
hotrodbob51		#12	[-]
Posts: 1527 (06/14/09 10:05 PM) Home Racing Guru! Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	bigmike312 wrote: I didn't have anything to do with the LSR race but if I did and had been one of the fast guys I wouldn't share any information. Why should I spend my time figuring out how to build a fast car and then tell the competition. I've never been one to tell someone how to beat me. Big Mike What we have done for this first race will only be the start of what we will do for the second race, but it is the basics only that can allow others to enjoy this racing as well. face it, this was a fun race and no one knew what the cars would really do. So what we will print here is a guide and help for others. I built 3 cars. The ones I spent the most time on did the worst. Carrera stockers with NSR motors. smooth chassis. One with alloy wheels and one with stock wheels. They both bounced right off the track. I ran a stock 27 tooth crown with a 12 tooth pinon on the Plymouth and a 23 tooth crown with a 12 tooth pinion on the Dodge. Stayed in the slot for one good 50+mph run. The third car for the mfg class was leading after the first round and consisted of a Ninco Lambo with lexan chassis, NSR Motor and red gear set. It ran a 35mph run, but the second and third runs were cut because of a wheel coming off. I could have caught Rod, I know it... I'll be back next year and faster too! Anyone can restore a classic car, but it takes a real Hotrodder to cut one up and make it cool! http://bob-beck-motorsportsannouncing.com/
JetGuy.fastlaneslotcar...	Sharing is benefitial to the Hobby !!!	#13	[-]
Posts: 192 (06/15/09 05:57 AM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	I believe it doesn't matter telling what we ran for multiple reasons, here's a couple... Like Bob said, This is just the first go-around for us, the next batch of cars we build will be different & probably faster. Sharing of information with the competition in its infancy will benefit the entire project as a whole and promote its growth. All NSR has to do is acquire a metal 23t crown gear and they could start selling duplicates of what i used, and sell LSR versions of the Mosler, or potentially other models. Wouldn't it be cool to have a 100mph slot car out-of-the-box ??? I would be honored indeed even with no aphiliation to the company. We would know why / how it came to be & that would be very satisfying. I intend to bring back the same car next year with alot more spares and see if it can defend its title, but i will also be building different cars, (unless i suddenly get sponsored by NSR)I will be building upon the knowledge & experience gained...Heck I'd like to run this type of event every weekend if i could...Need an unlimited class tho Yeah, i wanna go faster !!! Rodney Evans Chief Technician US Micro Jet LLC 900 Glendale Milford Rd. Cincinnati, Ohio 45215 1-888-894-5387 revans@usmicrojet.com turbinegooroo@Yahoo.com
ElSecundo		#14	[-]
Posts: 7916 (06/15/09 06:51 AM) Home Racing Guru! Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Rod, I totally agree. Sharing the information helps the whole thing grow. If nothing else, just a parts list like what you provided. It's the assembly that makes it all go fast, anyway. Secrets only stifle the growth. I like cottage cheese. That's why I want to try other dwelling cheeses, too. How about studio apartment cheese? Tent cheese? Mobile home cheese? Do not eat mobile home cheese in a tornado. Mitch Hedberg
Dyno Tom		#15	[-]
Posts: 19 (06/15/09 10:15 AM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Rod You are right on the money. I will post information about my cars later. and yes I did a lot of testing some things that you would think should work did not and I made a lot of parts two or more times and a lot of parts are now junk. The car was used up after only 3 race passes and 2 post race passes the one at 20 volts that did some real damage. Let me know if anyone would like information on the Dyno, it helped a lot to come up with a smooth car a high wheel speeds. Had a blast and I am looking forward to next year. I have never been around a better bunch of gear heads in my life. Dyno Tom
ElSecundo		#16	[-]
Posts: 7920 (06/15/09 10:27 AM) Home Racing Guru! Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	Tom and Rod, I can't say it enough -- congratulations on some really fine car builds. I bet that car is used up! Those speeds put an unbelievable strain on the parts, and I could hardly believe you were able to run that car again after the three timed runs. I like cottage cheese. That's why I want to try other dwelling cheeses, too. How about studio apartment cheese? Tent cheese? Mobile home cheese? Do not eat mobile home cheese in a tornado. Mitch Hedberg
Dyno Tom		#17	[-]
Posts: 20 (06/15/09 07:46 PM) Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	How I set up my car I looked at 1 to1 cars and found that F1 and IRL cars were fast, light, small and aerodynamic. So that was a good place to start. Car: Carrera F1 small, light and good aerodynamics, strong frame and I had one. Body: good aerodynamics, but would need to have more down force. I took the wings it had and made them a little bigger and gave them more angle of attack. I put skirts on the car to keep the air from under the car and added bigger side dams on the wings to keep the air on the wings and to help keep the car straight. If air can not get under a car then less wing is needed to keep the car down. I added a tunnel to the rear of the car to pull air from under it. I then blocked all the air intakes. Most of this was made from .010 sheet plastic. Frame: I cut out the center of the frame to make room for a bigger motor and to let any trapped air to get out the back of the car. Stock Carrera guide blade. Wheels: Fronts are Slot- It black plastic (the lightest wheel I could find) mounted backwards to help cover the suspension for better aerodynamics, running on Ninco ball bearings. Wheels: Rear are Ninco 18" with Fly truck tires and wheel disc to keep the wheels from pumping out air. A lot of air comes out of these wheels at 30k rpm. Running on Ninco ball bearings with a Slot-it gear.(23T) Motor: well used NSR 46k boxer (was faster than a new motor) with NSR gear (15T) Well that's most of it. Well all that I am willing to tell. A lot of testing and a lot of scraped parts and TOO many hours. A lot of work went into trying to keep tires on the wheels @30k rpm Dyno Tom
frank9129		#18	[-]
Posts: 1015 (06/16/09 02:15 PM) Home Racing Guru! Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	I have a gearing question. If fewer crown gear teeth is more power, and more teeth mean more acceleration then... 8/30 = 3.75 @ 40,000 RPM = tire rotation of 150,000 RPM if that is correct then a 7/33 = 4.71 @ 40,000 RPM = tire rotation of 188,571 RPM a larger diameter tire rolls farther that a small diameter tire. Bigger tire, smaller pinion, larger crown gear is the answer. Am I on the right track? I have to go to Capital Raceway this weekend and check out the dragsters. Crab Alley Speedway GIT-R-DONE
Robert Livingston		#19	[-]
Posts: 903 (06/16/09 03:25 PM) Home Racing Guru! Reply Quote More My Recent Posts Message Me Connection Blocking Invite Ignore User's Posts	frank9129 wrote: I have a gearing question. If fewer crown gear teeth is more power, and more teeth mean more acceleration then... 8/30 = 3.75 @ 40,000 RPM = tire rotation of 150,000 RPM if that is correct then a 7/33 = 4.71 @ 40,000 RPM = tire rotation of 188,571 RPM a larger diameter tire rolls farther that a small diameter tire. Bigger tire, smaller pinion, larger crown gear is the answer. Am I on the right track? I have to go to Capital Raceway this weekend and check out the dragsters. The smaller the pinion or the larger the crown, the more gear reduction. The more reduction, the higher the torque, and the lower the RPM at the rear axle. The larger the pinion or the smaller the crown, the less gear reduction. The less reduction, the lower the torque, and the higher the RPM at the rear axle. Torque times RPM equals power. The output power of your car is dependent on the motor, not the gears. Taking one of your examples, 8t pinion driving 30t crown (or spur) will give you 3.75:1 ratio. The motor turns 3.75 times for every 1 turn of the rear axle. The axle speed is found by dividing the ratio into the motor RPM. 40,000 RPM/3.75=10,667 RPM at the rear axle. By going to 7:33, you increase the ratio to 4.71:1, so you get less top end speed, but more torque at the rear axle, and more acceleration. The trick with an LSR car is to drop the numerical ratio down to the area of 2:1, or maybe less. Some guys put the wheels on the motor shaft, (1:1 ratio) but I don't know how fast they went. The top speed that you achieve is more important on a 250 foot track than the acceleration, provided you have enough acceleration to get up to speed before you run out of track. Last Edited By: Robert Livingston 06/16/09 03:34 PM. Edited 2 times.

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