I haven't done anything with it lately. In fact, I haven't been running my dyno much lately either. I've been working on driving and setup more than motor. I can out motor anyone at the track as it is now. But if I hit the wall a few times, I loose a lap, and all that extra power has gone to waste.

I've also been using Monsters almost exculsivly in my TC3. Yes they are slower on the dyno, but I can go faster with them on the track. Maybe its just a gearing thing. Maybe its because they don't seem to drop off as much through out the race as much as my other motors. I'm not sure, but they have been working fine so far.

A while back somone, I think it was John Stranahan wanted to know if I had some sample data files to use with Golden's DynoViewer...

Well... I have some now, not every conceivable type of motor... but I do have like 2 GM3s, 3 ROMs, a couple Paradoxs, and a MVP...

I never thought I'd see a MVP like this here... it's using brushes with the leading edge trimed a bit. The dyno data for it, looks almost as good as any EPIC motors I've got... I don't have much track time with these yet... but they look pretty good on the dyno...

anyway... have fun with these.

http://www.wiltse.net/zips/robi_data.zip


By the way... the newest DynoViewer can be found at...

http://www.wiltse.net/zips/new_dv_exe.zip

That was just a new program... you'll need the full instal from the previously released version to instal first (if you have not already) The last complete instal, is the same currently as it was the last time it was given in this thread... (a couple weeks ago or so...) If your new you may need this first...

http://www.wiltse.net/zips/DynoViewer.zip

I bought one MVP when they first came out, and it set the all-time power mark (stock)on my dyno that still stands today after many hundreds of motors. I know you need to try it for yourself, all i can say is i hope you have better luck on track than I did. I wasted a lot of time trying to get that motor to finish decent.

Hi Glenn,

I should have had you dyno my MHP motor yesterday at JCC to see what it looked like. I finally ran the thing this weekend (after purchasing it over 2 months ago). I had it geared down close to 6 teeth under what I normally ran my GM3. I didn't get to do any track comparisons by running the GM3 since I was trying to battle Aaron for TQ (since I knew I had a pretty good gear selection for the MHP I didn't want to switch motors). :D

Anyways, you might want to talk to FredB and see if he can get you one of his MVPs. He and Aaron ran them all last year and they were fast with them. I don't think Aaron has his MVP anymore, but it wouldn't hurt to ask him, too.

btw: What motor did you run in your oval main that had Keith Hamilton in it? Sucker was fast.

-Rich


Originally posted by DynoMoHum
I never thought I'd see a MVP like this here... it's using brushes with the leading edge trimed a bit. The dyno data for it, looks almost as good as any EPIC motors I've got... I don't have much track time with these yet... but they look pretty good on the dyno...

anyway... have fun with these.

If anyone wants a new MVP, Scott has them at the JCC races or one of us can bring one up to Lansing on a Friday or something. If you just want to run some numbers, I have an MVP to try.

Well, speak of the devil. Stop stalking me, Fred! :D

ROM? Am I missing something?

ROM = Revenge of the Monster

The motor I ran in the 4 cell 19 turn class was a Chameleon 2, with Putnam brushes in it. I have done very little to this motor, it's the only 19 turn I own. It came out of the box with hood alignment that looked pretty good, I tweaked one brush hood and other then trying differnt brushes and springs I haven't done much else too it. I started the day with a 2.22" rollout, and by the end of the day I was at 2.722" rollout. The motor was pretty warm at that rollout, but not too hot. I've dynoed other good 19 turn motors, and haven't really seen any that are much better then this one. I did breifely have a real Putnam Pro 19 turn Chameleon 2 motor, that had very simmilar power numbers, but had way more RPM then mine. At that time, I was not gearing my motor anwhere near the rollout I had at the end of the day on Sunday. Basicly I had been undergearing my motor previously. The finnal note on that run... My GP 3300s came back with just 45 seconds left on them at a 30 amp discharge, even so I wasn't falling off much at the end of the run. By my calcluations that's pushing about 40 amps average... depending on how that pack cycles out...

I really need some test drivers for my work... :) my driving needs alot of improvement, and I'm confident that many of my competitors could easily beat me with my own equipment... Heck I've seen them beat me with motors that were clearly slower then mine.

The MVP in that zip file looks differnt then any other MVP I've ever played with. I should have included a more typical MVP to compare it to. Basicly I've seen some with higher power, but the effciency isn't as good, and the RPM is much higher on a typical MVP. I did test this brush setup one day a couple weeks ago, but only had like 2 runs, and didn't have a whole lot to compare them to at that time. However I was impressed with it on the track, more then I ever have been with any other MVP.

Next time Rich, Fred, and I, get together at JCC or wherever, I'll be happy to dyno some of your motors... Heck I might even give you guys some of my motors to try... because I really would like to see what a good driver or two could do with some of my motors. I'm just now getting a handle on how to gear one motor to another based on dyno data. I'm realtively confident I can get within one tooth of a perfect match, if given optimal gearing for a referance motor. Watch out this weekend... Keith has one of my Paradox motors that was included in that robi_data.zip file. On the dyno it has about 5% more power then his best motor.... I didn't give him my Monster... I'm still playing with that, and it's the only one I own.

Oh, another thing... I didn't realise it... but my Monster is looking pretty awesome now... I've been tweeking on it so much, I never really stoped and took a look at it from a few steps back... I'm tempted to try one more thing with it... if it works as good as it has on some other motors, I might be able to eek out another couple watts. Still... I know there are better motors out there... DGPDX7V in that zip file is the best motor I've ever dynoed... It's not mine, but one of my competitors, I still don't have any idea how he got a stock motor to run like that...

Hi Guys. I've only just recently discovered this thread and been back through it all and caught up to current.

AWESOME discussion. Really learnt a lot from this (though I don't claim to fully understand everything)so keep up the good work.

One question: where can I buy (on the net) a "fiddle stick" that Dyno says he uses for set the spring tension?

Cheers!

:)

tgr,

Do a google search for "sonic fiddlestick" it should be the first match that comes up.

Thanks for the quick reply Snuffy.

Got it on Google.

Thanks again.

:cool:

"powerband"... in terms of 'stock' elecric RC motors... what does this mean? Is it simply a refferance to high RPM or low RPM? Or what?

To, me powerband refers to the location of power, in relation to the motors max RPM. Like on Gasoline engines, peak power sometimes occurs at low, medium, or high RPM, depending on lots of things related to tuning, valve timing, etc...

In my observations of electric RC motors, peak power ALWAYS occurs at the same basic location. At least this is true of basicly all the electric motors I have dynoed. Some motors have higher RPM, and lower torque, or lower RPM and higher Torque, but the POWER always peaks at the same point, which is basicly at about 50% of the motors maximum RPM.

Many people seem to think this 'powerband' can be moved on a electric RC motor. So far, I have not seen any evidence of this, at least not in what I consider to be the 'powerband'. I recently have gotten my Revenge of the Monster motor to put out nearly identical power to what I have long considered my best motor, a P2K. I would now like to show you something that compares these two motors of mine. I'd like to have some comentary on this subject of 'powerband' or on the subject of what may or may not make either one of these motors work better then the other in any given situation. I will ask you to ignore the fact that the Monster in this data has slightly higher power... I say ignore it, because it really is a very small differance, and I don't beleive it's significant in any way.

Please take the time to look at the following web page, the text, and both the graphs shown on the page.

http://www.wiltse.net/powerband.htm


A seperate but very closely related topic I'd like to discuss objectively, is... What if anything could possibly make a high RPM motor better then a Low RPM motor? Many people seem totaly convinced that the High RPM motors of today give them some advantage. My personal experiance on the track doesn't really lead me to that conclusion, but I know I often seem in the minority on this issue. I'm seriously trying to figure out if there is any way to explain what I may be missing. My gut feeling is that I'm not missing anything in perticular, and that my own personal observations are not flawed, but then this requires me to beleive that many of you are somehow mistaken in your beleifs... I am sincerly at a loss to figure out what makes so many of you beleive the high RPM motors are and advantage somehow.

Probably the only way I could ever truely solve this riddle is by doing some exentensive testing with some other people. Sort of sit down with several differnt motors, some top notch drivers, a good selection of pinon gears, and some time to figure it out. I would like to do this, and maybe someday I can get a few locals to help me... until then, I'd like to see if there's any way to figure it out just by talking about it.


By the way... the two motors displayed in that web page are included in the robi_data.zip file I put up previously... they are GROM7V and GP2K7V. If you wanted to look at the current or effciency of these motors, you could look at the data extensively if you want to.

Dyno,

Could you add efficiency to those? When two motors are that close the differance is usually efficiency. How does each motor run when it gets hot?

I'll re-due the images to include efficiency soon... Or perhaps add a way to show it as a option... The graphs get very busy when you show more then a couple data items at a time... When I did my last on track testing, I did it with 4 cells. The graphs at 5 volts look very simmilar in terms of equality... but my point is that my on track testing was done at realtively low voltage, and heat was not a big issue for me at the time. It is a good point however that testing with 6 cell application, may very well yeild something slighly differnt then 4 cell.

An alternitive would be to download the viewer and the data... but I'll try to make the data available on the web pages too...

I've said this before, but I'll say it again.

If we make a stock motor the old fashion way, with a full armature and a no hole can just like a normal modified motor is made, we would end up with a motor that makes too much torque and not enough rpm, so power will suffer a ton. To fix this problem, Trinity invented the slotted armature. It produced a bunch more rpm than the torque it lost, which made more power over all. They then continued this trend over the years by coming out with higher and higher rpm motors. I feel the racer community has been brain washed into thinking that more rpm is always better, and this belief does help Trinity sell more motors.

Now we have come to the modern era of stock motors. They all produce the same power, and with out any new advances in technology, we will not see any more power from a stock motor. Nothing has changed since the Midnight 2 was made rebuildable (Paradox). The P2K changed the asymmetrical web a little and advanced the timing of the magnets with dents in the holes in the can. The Green Machine 3 was a tri-rotor arm. The P2K2 removed 2 laminations off the arm, but was otherwise identical to the P2K. And now the Monster, which uses even less laminations than a GM3; it is missing the middle section, and it uses triangle shaped holes in the can to advance the timing of the magnets.

I see nothing in the changes to those motors which would make one make more power over another. So why do people think more rpm = more power, maybe we can find the answer with mod motors. What is the difference between a 20 turn arm and a 10 turn arm? I'd say that the 10 turn pulls almost twice the rpm of the 20 turn. So when it comes to mod motors, more rpm always equals more power. This principal has also shaped peoples opinions of rpm.

When we look at the Power and Torque curves of 2 motors after gearing is applied, we can clearly see that there is no difference between a high rpm motor and a high torque motor. Both motors, after geared correctly, will have the same torque at a given wheel rpm. Because torque is acceleration in a car, both cars will accelerate at the same rate. So therefore both motors will perform identical on the track.

Ok, I've added efficiency... it looks pretty good (not to busy), so I'll just make this the normal view.

On my computer it's hard to see the differnt colors of the efficiency curves... but the P2K is the one with the highest efficiency.

I don't see efficeincy as being a problem on either of these motors. Based on my own experiance I would think it would be extreemly hard to notice any real differnce between these motors on the track. (previous experiance related to many other motors included)

My own expernaces have lead me to trust the my dyno data ALOT. On track proformance for me pretty much always backs up my dyno data.

A side note... I see Josh Cyrul and Jim Deiter have been indicating that some of the Trinity drivers seem to prefer their motors tuned differntly. Josh recently apparenly was running a Monster with trimed brushes, and other drivers prefered motors will full faced brushes and differnt spring and/or cuts on them. I don't know exacly what to make of all this... I think it tends to point out that driving style and getting the most out of a motor is highly dependent on driving style and many other factors.

DynoMoHum -- I wish I had "answers", and I don't... But I do have some thoughts, much like Mike did...

Some of it may be the way we "perceive" speed. One example of this is at the local HobbyTown parking lot races. The Nitro sedans ALWAYS get all the OH's and AH's and "Wow that's FAST" comments -- but the STOCK electric sedans turn more laps! The Nitro guys have screaming, noisy engines that just make you 'FEEL' the speed, but they are "soft" on the bottom end and then suddenly come "on the pipe" and shred the tires and get sideways, so the locals cannot get the consistent lap times. The electric (stock) sedans are more "mellow", much "smoother", and thus 'FEEL' slow and look slow to the spectators because they don't make those "zoom-zoom" noizes. (Please note this if for "local drivers" of moderate skills -- I don't want to start a Nitro-vs-Electric fight -- OK?)

The same thing applies to high RPM motors -- even electric motors sound different... On our offroad track, you can almost tell what type of motor is in a truck or buggy by the way they sound in the air over the doubles -- the high RPM motors "sing" with a high pitch whine while the 'torque' motors are much more quiet... Another example -- I believe that CART advertises that their cars are the fastest closed circuit cars, but NOTHING sounds as fast as a screaming F1 car... We are conditioned to associate that screaming with speed...

Now -- if "perception" is part of it, how do you explain guys who swear they are turning faster laps with the high RPM motors... Part of the answer may be in the recent discussion of how the MVP motors with the Big Jim cut dyno strong, but feel "soft" to some but feel like a "rocket" to others. The short version is that if you feel you need low end YANK, then you will only "like" torque motors, since they fit your driving style. On the other hand, if you need a more mellow motor to smooth out your driving (or if traction is in scarce supply), a BJ cut MVP will smooth things out and your lap times will improve dramatically.

Another factor is just a match of motor type to driver style. I know some guys who can do better than me on the oval with GM3's or Monsters because of a compounding effect -- they can drive smoother, carrying more corner speed, which then means they can gear up one tooth more than I could, even with the same motor. So these guys are faster because of their style, and then because of their style, they can gear up and go even faster! I need a 'torque' motor because I scrub more speed in the corners, and need the "grunt" out of the turns...

I know this rambled and is a bit "random", but it's your fault for getting me thinking about this...:D

I think I understand what your saying Tfram, but still... my data seems to show that there really is vertualy no differance in where the power is located at on a modern stock motor, once you gear it right.


One of the things I'm thinking is that people don't gear things 'right'... that is that they wind up undergearing low rpm motors, and tend to be slightly on the overgeard side with high RPM motors. It's easy to gear a Monster higher then you would a P2K... by my calcultions, the motors in those graphs are geared 6 teeth differntly. (20% is more accurate) Some may not really beleive they can use their P2K with that much gear.

I'm begining to think that the differances most people see are either due to actual varations in power that is due to slightly differnt tuning of the differnt motors and/or production differances, or simply that they gear the one of the motors slightly differnt and don't really realise how much of a differnace it can make. However I really would like to verifiy this. I'm finding it harder and harder to state my posistion without either offending someone, or them just simply thinking I'm a total nut for thinking the way I do.

Fuel to the fire... :)

Here is a comparison of my newly tuned MVP with the same Monster from the other graphs... In this graph, I see what I would start to call a differnt 'power band'. If you look closely you can see that the Monster shows slightly better power in the middle RPM, and slightly lower power towards the lowest RPM and the Highest RPM.

Quite frankly I don't see this differance as being significant either, I just wanted to show and example (one of the only ones I've seen) of what I would consider as being a differnt 'powerband'.


http://www.wiltse.net/images/MVP_ROM_GEARED.gif

Think about this Dyno. In your discussions you're talking about the power band with gearing applied.
I would relate that to the powerband of the setup.
The powerband of the motor would likely be what determins what gear to use with which motor.
If you use stiffer springs on a motor your reducing the RPM and increacing the torque. This is what I'd consider changing the powerband of the motor.
With gearing applied the powerband of the setup won't change.

Make sense? Or am I completely off my rocker?

I went back trying to find some MVP data from before I tried triming just the leadinging edge... to try and compare the before and after...

Well... I found some old dyno runs that looked every bit as good as my new ones. That is with some narrowed 767 brushes, compared with just the leading edge trimed off of a pair of 4499s... Basicly the only real differance was in RPM and Torque... once gearing was applied the power curves looked pretty much identical.

So, Basicly I'm thinking that either way works about the same.

More and more I'm begining to think that with enough time and enough effort, I could make just about any stock motor work pretty well. I may even start playing with a Rage that I have...

Actualy snuffy, I've got some data that suggests RPM actual goes up when you use stiffer springs... at least to a point. There is a point where the stiffer springs start to cause the RPM to go back down, but they have to be very stiff springs for this to happen.

As for the changing powerband... yes I think that it depends on how you veiw the term 'powerband'... If you simply see it as making more or less RPM and consiquently less and more torque... then sure you can change it...

However in my opion the basic capablitys of any well tuned stock motor remain quite simmilar.


What I was really wondering is this... is there some inherent flaw in dyno data? Something that makes it totaly worthless when you start to compare a high RPM motor to a low RPM motor?

I don't think there is... but I do have at least some doubts. One of the reasons I have doubts is by seeing really fast oval guys go WAY faster then me with motors that appear to be down on power by around 8% or so on the dyno. Now I know this is exactly why we don't race dynos... but still I've dynoed motors from guys who have beaten me quite badly, and near as I can tell it has nothing to do with power as far as the dyno shows it... In this perticular case I was using a very good Chameleon, and the really fast guy was using a Kisbey 19 turn ARCOR motor, presumably with the timing cranked way up on it. On the dyno the Chameleon looks much better then the ARCOR motor.

A side note is that I've also seen REALLY fast guys go REALLY fast with Chameleons that look about like mine does... Way faster then I can go with mine. So... my doubts about the dyno are very small... almost non existant. Last time I spoke with some of the guys in question about ARCOR vs. Chameleon, I was told that the Chameleons are faster, but not by very much.

Maybe it's all in how you define Powerband.

I define it as the RPM range that produces the most useable power.

By that definition a low RPM motor and a high RPM motor will have significantly different powerbands even if they produce the same total amount of power.

With gearing they can be made to be equal.

Dyno, about your comments on someone beating you with a weaker motor...

I really have to admit this, but I race stock and mod with the same car on the same track with the same setup and tires, I simply change motors. Now I run a 10 double in the mod, which produces over twice the power of my stock. I'm lucky if I get the same number of laps with the mod. The mod just has too much power to handle. I can put all the power to the track, its just that trying to slow for the next corner is very difficult. But man is fun to go twice as fast through the strait.

Also, there are guys who beat me almost every race, but their motors suck compared to mine. They are easily 8% off in power too. But alas, we all have to go through the corners too.

Mike has a good point. The last few weeks at my track the layout has been a speed track. I really haven't been doing too well. I have to work hard to get into the A main. People with less driving ability are blowing the doors of me because they have better motors.

When the layout is technical, and requires more driving skill, I'm in the top 3. I race in the super stock class.(inbetween novice and Expert)
When I can run within 2 or 3 laps expert guys, I plan on moving up to the expert stock class.

DynoMoHum.

Can u make a chart showing power output in wattage versus amp draw (or load)? this is where i see the most difference in 'powerbands' RPM is merely a gearing function. the place where a given motor produces its peak wattage output in comparision to its amp load is the key. that is why a higher timed motor will generally outperform a lower timed one, esp. in stock. using your theory, there would be no point in having a timing limit, since u can gear a given motor to the same wheelspeed. most of the mods done to recent stock motors are done to simulate the effect of having more timing in the motor, given the 24 deg. limit.

Mike, I'm currious... a day or two ago you said you were now running the Monster pretty much all the time. However you also basicly agree with me that there is virtualy no real reason to expect the Monster to be a better motor. Why then are you runing the Monster and if I understand you correctly, you feel you are going faster with the monster??? What would you atribute this too, ohter then the possiblity of gearing that you've already suggested could be the reason.

Also... your really running something other then your dad's GM3 after you got it from him? How do your monsters compare to that GM3? If you've got the actual dyno numbers post them. From what I could see from your dyno data on that GM3, it was about as good as I would ever expect to see from a stock motor...

When I get a chance I'll show you the data in relation to amp input... However the effciency curves that are now on the RPM graphs, should give you the basic idea about what the amp load is...

As for timed motors having now advantage in terms of power... that's simply not true... If you crank the timing up, the power goes up too. Not just the RPM... There is no question that a motor with higher then 24 degree timing will put out more power... however the peak still occurs at something very close to 50% of max RPM.

Take a look at this web page if you want to see what cranking the timing up on a MVP will do.

http://www.wiltse.net/Timing.htm

I'll go through that same data, and show what happens when you gear some of those differnt dyno runs. Basicly the overall power will go up as timing goes up. It may take me a while to re-do that whole topic... I need to do it though, because I didn't have Golden's DynoViewer back then.

I run the Monsters, because they seem faster. They may infact be slower. Maybe thats why I'm faster with them.

I think I'm faster with the monsters for a few reason:
1. When I dyno the motors after the run, the Monsters are faster. (Remeber I have twin Monsters. They always dyno exactly the same.)

2. The fact that I have 2 that run the same; it makes the car seem more consistant.

3. I think the Monster spools up faster than most other stocks. I believe this is because it has so little iron mass. But I only have a TD45, so I cannot see spinup times.

4. Everybody else seems to go fast with them too. The fast guys have had to chuck their GM3s and MVPs and P2K's for Monsters. And their lap times have picked up. When I run the monster against them, I seem to run the same speed as them. Note, there are only 2 guys that run faster than me at my track. We are in the Pro class. They consistantly beat me, but noone else does.

5. I just need to learn to drive better. I actually had a run last week where I didn't touch the wall once. And if you've seen our track, its quite an accomplishment. We have sand bags everywhere and open ended PVC pipes. Plus huge bumps in the carpet that throws your car in funny directions when you enter a corner.

6. Simplicity. I have one of every motor out there. It would take me 3 weeks of racing to test them all. And thats just the fast ones.

7. My Monsters seem to run cooler than any of my other motors. I feel that I can gear them 1 tooth higher without smoking the motors, and I only have 60 seconds left on my Sanyo 3000HV @ 20 amps.

Oh, and I think that GM3 is finnaly dead. Last time I trued it, it was at .970. Dad game me the motor a few weeks back, and it smells funny now. I think I figured out why he gave it to me. I haven't run it sense he gave it to me. I wanted to this weekend, but I think its about dead. If it still runs ok, then maybe I'll send it to you, Dyno, for some testing. I'd like to see if it is really that good.

If anyone is wondering, I run Touring Cars (TC3) for 5 mins on a road coarse for 5 min in both stock and modified. I can pull 23 laps with the stock and 24 with the mod (If I'm really lucky). Records are 23 laps in stock (but faster than what I've done) and 25 laps in Mod.

So where does amp draw figure in? If you look at the pic, these are two GM3's pretty similar in power, yet at high RPM's mine (green) just doesn't draw the amps of the second motor? Keep in mind this is a "non" pro GM3, I have cut the comm to ensure its true, put in Reedy 767's and went to town. I imagine w/ a brush and spring change it would only get better. What can I do to bring the amp draw up? If amp draw goes up, doesn't peak power or not?
thanks
Jake

http://www.helmsfuneralhome.com/Jake/gm3_ampdraw.jpg

Mike... the situation you describe with how things are going at your local track is exactly why I wanted to investigate this phenomina... Basicly it seems that every time Trinity comes out with a new higher RPM motor, it eventualy becomes the motor of choice for many people. Yet in all my testing, I just don't see any reason to think that these higher RPM motors actualy do anything in perticular that should make them faster.

My thinking is that it's just that people buy new motors, and eventualy stop useing there older motors. I also beleive that it's just the nature of things that people continue to get faster over time. Not nessasarly because their equipment got better, but quite possibly becasue they got better... Eventualy people see fast guys useing the new motor, and they decide they have to have one too. Yet... I also know there are very good drivers who also insist that the new motor is faster then the old motor... I can't fully explain the whole thing.

I really want to enlist some top level drivers to do some testing, amlost a blind test, where I give the driver the car with the motor and gearing instaled without really letting them see what's in it... this would be alot of work to do well... but it probably would be the only way to really sort it all out. I think I could get at least one local oval guys to simply run one of my motors for me, after he's previously ran his... that would be easy to do, and could go along way toward sorting things out... I'm going to ask a guy this weekend if he's willing to help me out... Since it's a really big event, he may not want to get too involved but I'm going to ask anyway... Quite frankly the guy I'm thinking of is a good enough driver that he could win with a realtively poor motor anyway.


Jake... I'll get back with you... if nothig else... I bet Jake would run one of my motors if I let him...

Originally posted by DynoMoHum
Jake... I'll get back with you... if nothig else... I bet Jake would run one of my motors if I let him... If we are having 4 quals and a Main, I will be trying more than 1 of my motors. LoL Sure, I'll run one of yours.... you think I would say no after seeing how your motors run? :D

Ok, as long your gonna answer my question, I can stand to wait....I guess. :D LoL
Jake

I don't use XP, but boy does it make my app look fancy.

Why would you want to bring amp draw up? For a given motor, if we bring the amp draw down and keep the power output the same, then we have just created a more efficent motor. But to really answer your question, if you advance the timing, you will increase the amp draw. You can also put super glue on the bushings.:D

Jake,

I can't fully anwswer your question about what role AMP draw plays. For the most part I've started to think it doesn't play much of a role...

In my opion your motor and that other motor are so close in every aspect that it would be impossible to tell the differnance on the track.

Lots of factors effect amp draw, some of them are... hood alignment, broush compound, brush width, brush cuts such as holes, slots, etc...

Timing plays a huge role in amp draw, but we all know that we can't legaly change the timing on a motor... However I'm realtively confident there are some small variations in timing due to production tollerances and other factors.

Length of wire also plays a part, again this is not anything we can change, but production tollerances do exist.

Basicly the list of things that could effect amp draw are endless.

At this time, I don't beleive AMP draw is anything we should be trying to minipulate in a motor. Basicly I beleive amp draw is the symptom of some so many differnt things, it can't be used as a defining factor in how fast a motor will run on the track or on the dyno.

One more thing about this... There is a odd behavior that I have yet to fully understand, it has to do with how RPM and current behaive at in the last 20% or so of the RPM curve. A motor with a very fresh comm will have a very linear curve/line, as a motor get's a couple runs on it, the curve becomes more of a curve, and less of a straight line. RPM and AMP draw seems to increase at this point, and I don't fully understand what causes it. I'll try to find a good example of it and show exacly what I'm talking about. GP2K7V and GPDX7V are dyno runs that I would likely use to show this... GPDX7V is the dyno run from a Paradox that has about 3 runs on it... GP2K7V is a motor with a very fresh commutator.

Originally posted by DynoMoHum
A motor with a very fresh comm will have a very linear curve/line, as a motor get's a couple runs on it, the curve becomes more of a curve, and less of a straight line. RPM and AMP draw seems to increase at this point, and I don't fully understand what causes it. Looking at those two motors I see what you mean, that is odd. Could that be the dreaded "jump" on the Robi where graph goes nuts for a second? I see what you mean.

http://www.helmsfuneralhome.com/Jake/jitter.jpg

I know when I dyno stuff on Mel's Fantom, the higher the AMP draw, the better a motor is. Is this just on the Fantom or is it shown on the Robi as well? I understand the efficiencey side it, it seems like a motor that drew more power would make more power to a certain extent. Mind you there is a limit for that, IE putting super glue on my motor would bring up the amps but would kill performance. LoL :) Now, super glue on Glenn's motor might give me a fighting chance..... LoL

Mike, I have been playing with the Dyno Viewer for a couple of days now with Glenns data. It is an AWESOME program!!! Keep up the good work, your right, it doesn't look to bad in XP. :)
Jake

If you look at the pic that I put up, the Paradox has little "jumps" all over the place, I wonder if it was the dyno run? Bumped the table or something? I dunno what would account for that, I don't know enough about the Dyno its self. Out of curiousity, how sure are you that it is related to the motor and/or comm? Maybe the comm gets just slightly out of true about that run? Does it continue to do this until you cut it or does it eventually stop doing? Weird. :confused:
Jake

I need to stop looking at my old GM3 against anything of yours. I'll have you pull my GM3 and my Monster on saturday so we can update those files. Trust me, my GM3 has gotten faster since you ran it on your dyno....... :devil:
Jake

The little bumps are 'glitches' and that's a minor example of such a glitch... Some motors will almost always have glitches on the Robitronic dyno. It's something that I basicly ignore if they are small like that... If they get big, I ussualy just thow out the dyno run and try for a better run... I can't explain what causes this.


As for amp draw as you speak of it in terms of the Fantom... Basicly that type of thing isn't really available on the Robitronic dyno. I'm not sure that it really says a whole lot about the motor anyway. Mel has just simply observed that motors that show up as being good on the Fantom, almost always also pull alot of current while the dyno run takes place. I think that number is the actual current that the dyno itself is pulling from the 12 volt power sourse during the run. It obviously would be somewhat related to the dyno data itself, but just how closely it's related to actual power output I could not say, and I personaly would not use it as an indicator of motor proformance.

I have found a really good example of interesting behavior I have observed on nearly every motor I've ever dynoed. This following graph reperesents the same motor. M19-I-01(Motor 2) is the motor with a fresh commutator. Motor M19-Iaf2(Motor 1) is the same motor after the motor has had at least one run on the track. I don't know for sure how many runs this motor had on it, but I know it was at least one. I also know that this increase in RPM and AMP draw near the tail end of the dyno run occurs on ALL motors once they have a run or two on them. This is something that I'm just now trying to understand. I have never mentioned it before, because I have no idea what really causes it, or if it is a sign of something good, or a sign of something bad. Recently I've been thinking it's a good thing.... however I can't tell you why... neither why it happens, or why it would make things work better on the track.

Any opions about what would cause this would be welcome.

http://www.wiltse.net/images/M19_BAF_A.gif

The RPM based graph of this same two motors can be seen here...

http://www.wiltse.net/images/M19_BAF_R.gif

It could be due to brush glaze or that the brushes are now fully broken in.

rowle1jt,

I allways want to produce the most HP with the least ammount of current.
Raising the current without producing more HP only causes more heat.

I wouldn't worry about the difference in current.

That makes sense. I was just curious, the thing is, my GM3 doesn't run hot like some other peoples do. I have tried changing gearing and then it is apparent that I am overgeared or under geared. So that graph is basically showing me that my motor will run cooler compared to the other one on the graph right? Maybe the efficiency explains the 9 and 10 minute practice sessions..... LoL :D
Jake

If you look at both of the graphs, you can get a little better idea of what's causing the "glitch" in this case. Two things point to the problem being "commutation". What's causing the problem could be a number of things, brush bounce, a carbon deposit on the comm, or my guess is part of the edge of the brush breaking off bouncing the brush as it runs through.

If you look at the graphs, they can give hints as to where the problem is coming from. In the graph you posted on the forum, the glitch lines up with a specific current point. On the other graph you can see that the current draw is the only thing that's jumping around. I don't know if this is a bad thing or not because the motor accelerates through that area so quickly it's not a big affect on performance.

I would assume that the Robi samples at a much higher rate than the Fantom. This is a good thing but it shows any glitches that happen during the very short run-up on the dyno. The only thing that I don't like about acceleration dyno's is how quickly they take data. A dyno with a slave motor holds things steady long enough for these things to stabilize.

Next time you see this, try carefully removing the brushes and taking the edges off. If that fixes the problem, it's my guess from above.

FB

Actually... in my last graph, I wasn't trying to say anything in perticular about the 'glitch' in that graph. I basicly just ignore those things at this point in time. I could show you a whole bunch of really ugly graphs with huge glitches in them. It may have something to do with commutation and/or brush bits falling off or what ever... I don't know, I've basicly given up trying to figure it out. I do know that on some motors it happens ALOT, other motors it rarely if ever happens. I also know that Robitronic claims it's the bushings causing it, yet I've seen it happen with motors that have bearings too... so I don't buy the bushing argument... My best guess would be commutation... It doesn't seem to have any bearing on the proformance of the motors however, so I just continue to ignore it...


The increase in RPM at the end(near max RPM) of the dyno run... The brushes are fully broken in in on both runs. I've seen this over and over and I know for sure it's not a matter of brush breakin... My best guess is that it has something to do with the little chared marks you get on the commutator after you've run a motor a couple times. When ever those marks are present, you will get this type of 'flip' where the RPM inreases at a higher rate then it had throughout the rest of the dyno run.

If it were brush glazing, or something like that, I would expect the RPM and amp draw to decrease rather then increase.

I know for a fact that motors seem to run just fine with this condition, in fact I think they may actualy run better. I'm starting to do motor maintaince much less frequently then I used to, and so far I have seen no ill effects from this decrease in maintaince. I figure as long as the peak power doesn't go down much, I'll take the extra 'kick' at the end of the run, and hope it really does translate into on track proformance, as it would seem it would based on looking at the dyno data.

FYI...
Good news and bad news... :) Good news is there is a new version of the DynoViewer... bad news is that to use it you have to instal the new version yourself... it's not done for you... :)


Mike Golden has updated the full instal of the newest DynoViewer. I've put it up on my web site, and it can be found here...

http://www.wiltse.net/zips/DynoViewer.zip


This is apparently version 1.3.3

I haven't personaly tried this version yet. Some new features... one is the new 'perfect torque' feature that matches up the torque of two differnt motors, and 8 out of 10 times gets you a pretty good starting point for gearing between those two motors. (Sometimes I tweak it a little from that point). Another nice feature that has been added, is the ablity to change the size of the graph as the size of the window changes... this should be cool, I haven't seen it yet though. I think he also has a way to save Fantom Facts II data into a form that would allow you to recall it later by useing the 'load Robitronic data' menu item... No it doesn't make it exactly like Robitronic data, but it does use the same format, so the program doesn't no any differance between the two at that point.


PS... I don't think 'perfect torque' will work with CE turbodyno data... but should work pretty well with either Robitronic or Fantom Facts II data.

Dyno Ho Hum, Clicking on the above link yeilds a 4.04 error
File Not Found message. Please check and resubmit if incorrect
Thanks:roll:

Sorry, I spelled Viewer wrong... should work now.

I hate the fact that my 4th and 5th grade teachers basicly taought me nothing about spelling.

GN the new speeling got me there........
BN when unzipped and opened in Micro Excel it
looked like hyrogliphix.:confused:

See I musta been lookin out da window when I shoulda been payin attention to what they was learnin me!:wave:

Not sure what your saying now about the zip file... I downloaded it myself, and un-ziped it... there are like three files that should come out... if you double click on the setup icon, it should fire up the instaler... it worked for me...