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Old 12-25-2003, 09:28 PM   #16
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I race 19T Spec, and mod, with a 10T limit so I use a 10x2. 19T is a fun class, and has alot of power compared to stock, but it's still a 19 turn machine wound motor. A handwound 10 feels much more powerful. Going through the infield with my Orion Element (19T) I have the throttle pegged on some sections of the track, whereas with a 10x2, if I did that I'd be into the wall. Full blown modifieds also have more top speed, like DynoMoHum has been saying, they are an all-around more powerful motor.

That's not to say 19 turn isn't fast. It's a hell of a lot faster than stock, and is an excellant class to "step up" to mod. Even racing mod I still enjoy 19 turn. It's fun to have another class to race, and the difference between 19 turn and mod isn't as much as stock and mod, so my setup works in both classes which is a huge plus.

DynoMoHum - You seem to know alot about motors in general, and specifically about the Robitronics dyno. I'm interested as to why you look at the 40-80 amp range? I tend to look at the 20-30 amp range, because when I'm done with a 5 minute mod race, I have 60-120 seconds left in a 3300, meaning I'm drawing significantly less than 30A on average throughout the race. I might draw 80 amps when I pull the trigger to take off from the line, and probably draw 40 amps often, but only for a split second. I'm just curious as to why you look at that range.

I'd also like to know what sort of numbers you get for a 10x2 mod? I'd just be interested to know what you'd consider "good" for that wind, because I don't know many other Robitronics users I can compare with. Also, have you tried the Orion Element 19 turn? I get significantly higher numbers with that than what you're Chameleon 2 is showing, if that is what you'd consider a good motor.


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Old 12-25-2003, 11:09 PM   #17
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DynoMoHum claims a 12t is more efficient and I disagree. A 12t is more powerful just not as efficient.
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Old 12-26-2003, 06:08 AM   #18
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Speedo,

I don't look at the 20 to 50 amp numbers,, well I do, but I don't focus on them, the only reason that range is being discussed here, is due to this debate going on about if a 12 is more effcient then a 19 or not.

That range simply came from looking at the graphs I showed, jsp noted that the 19 turn is more effcient over that area in my graphs.

I've never spun up a 10 turn on my dyno, the lowes't I've ever done is a 11 turn, and I'm not even sure I still have the data for that. I do have some data from another guy for a 9 turn, but I don't know much about them really. At this time I wouldn't even begin to try and tell some one how to pick one 10 turn over another... Other then to say the one that's more effcient is likely the best choice.

Heck I don't even know much about a 12 turn. My discussion here is mostly theoretical, and my orignal statments were made based on memory and the fact that in general a lower wind is for the most part, more efficient then a higher wind.

Jsp, and ohters....

The 12 doesn indeed produce more power from 0 to 100 % of maximum RPM. It is more effcient over most of that range, however there is a point where the motor is less effcient, yet it still puts out more power when it's operating in that range (seems to contradict it self, but it really doesn't) The motor consumes more power at that point, but it's still kicking out power like no tomorrow.


THe basic fact is this... Lower winds put out more power. Sometimes they do this by consuming more power. THe low wind motors also will go faster and accelerate harder at the hands of a capable driver.

If you haven't noticed yet, the confusion here comes from the differnace between looking at data in relation to Amp input (as many pepople do) vs looking at the data in relation to percentage of maxumum RPM.

For most purposes when you look at dyno data in relation to amp input, all your really looking at is effciency. look at that last graph(12v19a.gif), you'll see that the power output of the 12 turn from 20 to 30 amps is almost identical to that of the 19 turn, the 12 is within a watt or two.

Effciency is important, but in most cases it's not more important then shear raw power.

If lower winds were't faster, we wouldn't see open mod drivers using lower and lower winds every time you trun around...

Anyway, we've gotten in to a debate about picky little points that don't matter much...
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Old 12-26-2003, 06:16 AM   #19
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OK USING your data from yYOUR last graph and baseline gear ratios given by a pro who races for losi here is what I arrive with....

12T----------

Gearing 29/128 on a Losi xxx-s
34749rpm/ 8.298 FDR
4188 Revolutions of the wheel

19T-----------
32/128
31981/ 7.520
4252



NOW- which motor will have higher top speed???

Sure you can gear up on the motor if you want to smoke it..... let's just say you push things a little with a 30 pinion


30/128
34749/ 8.021
4332

However remember the motor your showing data for is a D2 and you overgear it and it won't be able to push the car meaning it will never see peak RPM's..... HAHAHAHA!!!!!

Like I stated earlier- the top end speed will be negligable, but the acelleration will be quicker giving the illusion of higher top end.....

NOW more about your graph in another post........

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Last edited by IMPACTPLAYR; 12-26-2003 at 06:56 AM.
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Old 12-26-2003, 07:11 AM   #20
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DYNO- sorry but your littl;e graph thingy is all but useless for compairing 2 unlike motors... Don't get all offended hear me out.....

Along the bottom the graph goes from 0-100% RPM... well the 19T's peak RPM is 2768rpm less than the 12T.... 2768 is a huge chunk of 34749!!!! that's 12%!!!!!

So the 19T 's info should end at 88%, when you do this the 19T's profile or curve will be much steeper, which in a reality means the 19T will spend much more of it's useful life at a higher power and efficiency level....

However your graph does work well when you want to manipulate how the facts are presented to prove your point........

Don't get mad dude, but the only time that graph is useful or acurately depicts the facts is when you are comparing 2 like motors with close max RPM.....

BTW: on a smaller track that 19T will spank that 12T anyday!!!!!! AND I believe I have proven that....
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Old 12-26-2003, 08:50 AM   #21
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I was thinking the same thing when looking at the charts... You can't compare motors without taking into consideration ther RPM range...
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Old 12-26-2003, 09:25 AM   #22
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TO get back to the original question for a moment.

It is my belief that in the hands of most of us average to above average drivers that we can all drive faster with a 19t on a roadcourse than with a 12t or lower wind. A 19t to me is easier to drive than stock because the added power and torque helps to steer the car when needed. Also-they feel verty similar to stock motors in terns of braking, etc. They slow down when you lift.

So-if "Fun" os what you want-strap in a 9 to 12t and have fun. But I bet you'll go faster laptime wise and break less often than with the full blown modified.

Now if your a "great" driver already-why of course you'll go faster with a mod than a 19t.

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Old 12-26-2003, 11:38 AM   #23
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I run both a 12x3 and a vareity of 19s at my track. I am faster with the 12x3 everywhere on the track and by .5 a lap or so but I am far more consistent with a 19t (because I suck at mod).
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Old 12-26-2003, 06:15 PM   #24
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I beleive you guys are not fully understanding what the graphs that show both motors with a percentage of max RPM are showing.

Each of the motors data is show in relation to percentage of it's own max RPM, not the max RPM of the highest RPM motor... SO no the 19 turn should not show up as 88% of max....

THink of it like this... if you geared each motor so that it each motor so that they both had the exact same RPM at the wheels. (two differnt gear ratios one differnt one for each motor)...

I don't have time to explain it further right now, if/when I do explain it further I'd rather use Golden's DynoViewer to display the data....
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Old 12-26-2003, 07:39 PM   #25
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NO DYNO, I fully understand, however comparing the 2 motors in that format is misleading..... the 2 motors don't top off at the same level and they don't rev at the same speed, so you graph is useless.....

Although I have read alot of your previous posts and you just will not admit that what you are using isn't the best or even dated..... Face it you CANNOT compare 2 unlike motors in that way.... the 19T DOES top off at 88% (87.5% to be exact) of the RPM of the 12T.... The powerbands of 2 motors just aren't the same... BASICALLY you are grading the whole class on a curve........ NOT FAIR
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Old 12-26-2003, 07:46 PM   #26
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Quote:
Originally posted by DynoMoHum
THink of it like this... if you geared each motor so that it each motor so that they both had the exact same RPM at the wheels. (two differnt gear ratios one differnt one for each motor)...
This would be very hard and very time consuming. To do it correctly you would have to find the perfect setup and driver(impossible), then find the perfect motors, find the sweet spot for each motor setup wise then also gear wise. After that you would have to bit by bit change the gearing so that you were to have the same rpm at the wheels(if you can even get it perfect). You would have to find the perfect middle or else one of the motors would have an advantage. For example, you couldn't change the ogr of one motor a little and the other alot, it would have to be perfectly equal on each motor while keeping the rpm *to the wheels* on each motor the same. Good luck.

Also the setups would have to be different for each motor. Stick a stock motor in your car and set it up, now stick a 12t in your car, gear it properly and see whether the setup is perfect. I seriously doubt the setup is spot on.

Imo this is rediculous. Most will be more consistant with a 19t, but they may be able to make it around the track faster with a 12t. This is because a mod can out accelerate a 19t, when you make a mistake or miss a line you can make up the difference with a pull of the trigger.

Last edited by fatdoggy; 12-27-2003 at 06:44 AM.
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Old 12-26-2003, 07:50 PM   #27
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What exactly do you mean by 'top off' ?

What are you refering to when you say that I can't admit that what I'm using is dated? or isn't the best?

What is the ratio of the transmission on a losi xxx-s ?


Do you have a guess to how much power it takes to keep that losi moving at top speed down the back strech? Just a estimate is fine... 40 watts? 50? etc...
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Old 12-26-2003, 08:48 PM   #28
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Quote:
Originally posted by DynoMoHum
What exactly do you mean by 'top off' ?
Peak RPM.....

Quote:
What are you refering to when you say that I can't admit that what I'm using is dated? or isn't the best?
I have been reading posts from you on several message boards for asome time now and you will never admit the Robi dyno isn't perfect and software that prints the chart is not exactly perfect at comparing 2 unlike motors......

Quote:
What is the ratio of the transmission on a losi xxx-s ?
1.88- agian I am not compairing apples to oranges like your graph I am not giving a Losi ratio for one and a tc3 for the other.....


Quote:
Do you have a guess to how much power it takes to keep that losi moving at top speed down the back strech? Just a estimate is fine... 40 watts? 50? etc...
I don't need to I am going by your graph and your information just stating facts........ how much power it takes is negligable because you are racing dynos here not Losi's and in a perfect world the motor will reach absolute peak RPM by the end of the straight....

Like I stated earlier that graph is the wrong tool for comparing 2 unlike motors..... You are the one posting the graph and saying here is proof.......

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Old 12-27-2003, 12:03 AM   #29
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Your wrong impact... I have stated on many ocasions that the Robitonic dyno is not perfect. It has flaws just like every ohter RC dyno on the market. I happend to think that the flaws it has are less of a problem for me then are the flaws of other dynos.

I have also admited on many ocasions that I don't really like the way the Robitronic softare produces it's Percent RPM graph. I think it has flaws that often show up. The flaw is bascily that it doesn't always caluclate max RPM very well for one motor or another. The reason I like Mike Golden's DynoViewer so much is that it doesn't have that problem, as it doesn't really ever attem to define max RPM, it just graphs what you tell it to graph.

Nothings perfect, but I am confident that just about any 12 turn motor ever made is capable of producing more top speed and out accelerating pretty much any 19 turn motor ever made.

The hole point of the graphs is that it shows just how much more power a 12 turn will make compared to a 19 turn motor. The way the Percent RPM graph is done, if/when you take the gearing so that both achive the same wheel speed at max RPM, the power output you'd see at the wheels would be very close to what you'd see on that graph. At max RPM in the graph, they both have pretty close to the same power. Now when you put all that into a real situation in a car, the motor that produces the most power is going to be capable of going faster, primarly because you can gear it up more.

I wasn't accusing you of comparing apples to oranges like you are accusing me of, I just wanted to know the ratio of the transmission. I had intended to do some further explinatations using dyno data, however I can now see it is futile.

If people are really interested in knowing how a 19 turn compares to a 12 turn on the race track, we should probably go as Josh what he thinks, I'm sure he could tell us.
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Old 12-27-2003, 12:42 AM   #30
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Ask Josh..
And so it has been done.


well guys,
I have to agree with Dyno, stating earlier his not so perfect dyno, as all indeed.
Also he rarely uses the original software, as he also stated in his last post.
Also on the other boards, he said that quite often.

But what I like to see is this healthy and friendly discussion to go on in the same manner it started.

Listen even the greatest minds in different fields follow their own beliefs and logics.


Although, I personally have no dicedied on this topic.
I do know Dyno is guite good at deriving correct conclusions.
I just have not time yet to sink this one in.


No I am not agreeiing at this time with anyone yet!
We'll see what happens.
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