I left out the tranny reduction -- for our pancars its 1-1.

But for sedans and buggies, I'm not sure where it goes in the formula.

Fixed bug...

I had Tyre * Ratio, not Tyre / Ratio.

New Version is 1.3.1

Goodwrench...

With fantom data, you should be able to get most torque curves pretty close to paralell with most any motor of the same type... the ones with more power will be higher torque uniformly across the entire RPM range... this is if you follow my method... If you use the "apply gears" button, then you will often get a torque curve that intersects at one point and is higher or lower on either end... My personal opion is that is not the correct gearing... at least not if the slopes are greatly differnt with the same type of motor...

Great program! I think there is a minor calculation error for the suggested gearing formula?

The reason why is I used two motors and one had a lot less RPM but a lot more torque than another motor. The higher RPM motor (my base motor) is geared at 31. However, the program told me to gear the higher torque (less RPM) motor down to a 28 pinion. In reality it should be geared up to 34.

I think the factor should be divided and not multiplied?

-Rich

Here is the motor data I used:

Motor 1 - GM3

RPM Torque Watt Eff Amps
24006 4.2 74 71 14.9
22643 5.6 93 74 17.8
21761 6.5 105 75 20.0
20906 7.4 115 74 21.9
19943 8.5 126 72 24.9
18846 9.5 133 68 27.8

Geared 31/100

--------

Motor 2 - blue end bell

RPM Torque Watt Eff Amps
21895 4.8 79 75 14.9
20506 6.4 97 77 17.8
19587 7.3 106 75 20.0
18336 8.3 113 73 22.0
17604 9.4 123 70 24.9
16569 10.6 130 66 27.8

-Rich

I had exactly the same thing happen with a Monster as Motor #1 and a GM3 as motor #2. The GM3 turned less RPM and it still told me to go down in pinion size for the GM3.

Mike,

Keep up the good (and might I say very guick) help for all us racers.

Thanks....

Pizzadude

Mike is the tire dia in inches or can I also use mm's...
Or maybe you could make this an option in your next release?!

Thanks for the gearing calculator!

Pizza

I have a question about gearing for p2k and green3,,I always hear that the p2k needs 2-3 teeth higher pinion than the green3, however my Fantom program is telling me to run the same pinion gear, maybe 1 tooth more, depending on track size(105, 110, 115, and 118) for the green3. Spur is the same size for both. These motors have a few runs on them, grn3 power is 61.95, 19560 @ 3.1, torque is 93, p2k is 59.40, 18059 @ 2.7, .911 torque...Where am I going wrong with this deal??? I have never seen this gearing difference show up in the program, seems to be the other way..

PizzaDude,

It doesn't matter. If you put in mm, you'll get mm out. If you put in inches, you'll get inches out. The only thing that varies is weather your talking about diameters, radii or circumferences. But I already allow for that.

Thanks Mike,

I see that now...

Pizza

Yes, I think Mike has a boo boo in it... It seems he's either named the "referance motor" as the "gear motor" or the other way around.... the gearing info is basicly just the oposit of what it should be... unless I and others are just confused... I hate to say it, but I think it's a mistake...

This really is a great program... If I'm not mistaken when I pluged other data Rich had given us previously for his Cleavland Paradox motor and a Monster motor he gave us data for on the other thread... it would require like 6 or 7 teeth differance in gearing... The data for these two motors was included in the dynodata.zip file I gave earlier.... If this is accurate, it's way differnt then what I beleive Trinity has been telling us... Don't they say something like 3 teeth differnt??? perhaps they are saying 3 teeth differnt then a GM3... that maybe I could beleive... I haven't really compared a GM3 to a Monster yet... hmmm I do have dat for Mike's GM3 and his Monster...

I know I feel much more confident that I could take a motor out of my car and place anohter one in it and have what I beleive should be gearing that is very close to what it should be... assuming the first motor was geared well... If the dyno data is accurate, and my method of selecting simmilar gearing is correct, I beleive I should be able to finnaly swap a motor out and not have to do a whole bunch more fiddling with gears and on track testing... but only time will tell if this holds up well or not... I am exteemly hopefull that it will.


Well I went and looked at the data for Mike's Father's GM3 compared to Mike's Monster (the strongest of three dyno runs he gave) and it said about 4.5 teeth differnt for gearing...

I beleive there is not doubt if you only used 3 teeth differnt like Trinity says, the Monster would either be faster on the track, or burn up... one of the two... however I don't think that would be the ideal differance in gearing...


One thing I eventualy would like to discuss with TurboDyno guys... what is it that seems to make the lengtht of the 'torque' curve (and other curves too) of a higher RPM motor longer then the curve of the lower RPM motors? (I'm talking about after you show the data with differnt gearing) Is this just some odditity in the way things work when using a Dyno such as the Turbodyno? or is this somehow indicating that more RPM is better???

I beleive it's a oddity of the way the dyno is doing it's job... I don't beleive it indicates anythign about the proformance of the motor... I think you just have to imagine that the proformance for the lower RPM motor will continue on in the same general path as it's taking... baiscly that it's a matter of perspective and understanding that your looking through a window so to speak at this bigger thing... I think since the torque at the dyno is lower for the high RPM motor, the data is spread out further with relation to RPM... That's my theory anyway...

I hate to be the bearer of bad news...The rollout is a bit off.

Oh... for the record... if there had been a program like Mike's available and a interface between the TurboDyno and a computer so that the data would transfer automaticly.... I may not have sold my TurboDyno...

If someone was extreemly ambitious, I bet a IR interface to the TurboDyno could be made... But I'm in no way shape or form suggesting that anyone such as Mike do this... However that would be one extreemly cool thing for TurboDyno users...

Hi Glenn - I don't know if you want to use the Monster Stock numbers I gave a while back for comparison. :-) I don't think I fully broke in that motor and the brush setup I put on it doesn't seem to work very well. I am going to mess with it a bit today and use a different brush setup and see what happens.

Did you get the updated .exe file Fred? we thought we had the rollout calculation fixed yesterday afternoon...

The package isn't updated yet... and it looks like there is at least one other bug that needs fixing so the package won't likely get updated till the others have been fixed...

I have to apologize to Mike... I've been acting as his chief beata tester... and obviously I haven't done my job very well... my only defense is my work is as good as my pay... :)

Fred, version 1.3.1 has the corrected roll-out. :)

missed the post...

Well...

I have to say that my work is as good as my pay too. :D

I'll have the new bugs fixed soon.

I'll disagree with you, Mike. So far your work is priceless (in a great way) compared to your pay. :D

This program is something I've been looking for for a long time. I'm sure if you wanted donations you'd get it. I, for one, would donate. :)

Ok, here it is, Version 1.3.2

I flipped the way it calculates and applies ratio's to the motors.

It now tells you to gear a RPM motor lower than a Torque motor.

If anybody wants to donate money...

I do take Paypal. All proceeds will go to new motor purchaces. All you need to do is use my email, mike.golden@sencore.com :D

Super Mike!

Hey ... back to a post I made a couple days ago.. what do you think the amp number should be in the "apply gears" section for 4-cell stock oval ??

Does anyone have that info ?

Thanks

Also, I'd like to hear suggestions. You can post them or email them. Or call, or snail mail, or tell me or what ever. (The last sentence is me being sarcastic to myself)

TeamGoodwrench,

If you look at what Dynomohum said a few posts back, there might be a better way. Basically, if you make the torque curves look parallel when the graph is in RPM view. There are a few caveats to this, but he talked all about it above.

OK.. I'll try that. I thought he was saying to make them overlap -- which mine never do. Making the PARALLEL makes sense.

Thanks!

Now that my internet connection is working again...

The gear motor rollout has the ratio applied backwards. As the calculator gears down, the rollout gears up.

Thanks for all the work!

TemGoodWrench:

To choose what amp draw to do the "gearing," you should have an estimate for the average amp draw of your motor during a race. Do do this, you need to have cycled your batteries at some point. For example, let's say your batteries were cycled at 30 amps and discharged in 280 sec. You then race. After the race, discharge the pack at the same 30 amp setting to 0.9 volts/cell. Let's assume this comes out to 60 sec. (The key to this being "easy" is to cycle and dump at the same amp draw.) Your average amp draw would then be 30*(280-60)/280 = 24 amps. Now comes a little be of "art." If you're running oval and never lift, this is probably a pretty good average amp draw. However, if you are lifting in the corners, or running road course where you lift, then the actual amp draw is probably slightly higher, maybe 26 amps or so. This will get you close for an inital guess that can have the gear ratio refined on the track.

RWB -- Thanks!

Goodwrench.... If I could get your data I could pretty easly show you what I think is the best way to do it... without the data it's very hard for me to explain my ideas... I could use snuffy's data to show you some examples, but I think it would be much easier and clearer if I just showed you with your own data.


Fred... are you still using the older version? or the most recent version? (I haven't even tried Mike's newest version yet... I just got back home from a Dr visit...)

DynoMoHum -- I'll get you the data over the weekend. Thanks for the offer !!!

I use a Fantom -- what is the best way for me to get you the data ?

I beleive the average amp draw idea is slightly flawed. I don't think that it's totaly baseless or meaningless, but I do beleive the differnt motors can operate at differnt amp rates and be more or less effective depending on lots of factors. Primarly efficiency... but anyway...


My basic idea where Golden's dyno viewer comes into play has nothing to do with amp draw, or such... it has to do with on track testing to find the correct gearing for a motor. Then taking that motor's dyno data and comparing it to another motor's dyno data... then you use something like the gearing slider on the DynoViewer to choose gearing that will most closely resemble the torque output of the motor that you know works well... Depending on effciency and other factors you may be able to gear the motor up or down a little from this point to go even faster...

In the end one motor might work best at a average of 25 amps, and another might work best at a average of 27 amps... it depends on the effciency of the motors... Obviously the more current you use, the more likely heat buildup will become a issue... However + or - 2 or 3 amps may make you go faster or slower... but still Torque at the wheels is what really makes you go fast on the track.

This is kinda of a new concept... not really new, but differnt then many of us had previously been considering...

Average amp draw is a good thing to know... but it is only part of the picture... because of effciency mostly amp input is somewhat of a meanigless item by itself.

I'm still refining my ideas on all of this... so bear with me... :)

Fred B has on track data that shows 45 amps or so is not unheard of in roadcourse racing... and in fact may be hit once a lap or more...

For oval racing, it's differnt... Diffent for 4 cells then it is for 6, differnt for short courses vs. Long... differnt for Stock then it is for 19 turn, etc... For 4 cell I beleive about 30 to 20 amps is the most important area... but depending on which dyno you use... 30 amps on the dyno might not be at all what your motor sees in the car... the dyno is just a rough estimate in many cases... No dyno gives you exactly the same condtions as will the motor will see on the track and in your car...

For example... if you put a 30 amp load on a 4 cell pack, the voltage will not be 5 volts... and the current at 3.2 volts is much diffent then the current at 5 volts.... So current numbers on a dyno are not one for one with current numbers in the car....

Goodwrench... I beleive that the Fantom Facts II dyno keeps all the motor data in one file... I forget the name of the file right now, perhaps someone else will give us the name... I'll check it out eventualy and get back with you...

Theoreticly you can either email me the file, or post it somewhere on the internet and tell me where to get it...

If you send me the file with all the motors, tell me a couple in perticular that you are interested in, then I could start looking at those first... I think once I show you my idea, you'll be able to duplicate the same basic tehnicque quite easily...

Snuffy gave us all his dyno data way back when... (a few weeks ago... I bleive the name of the file is somewehre in a previous post to this topic... I'll go look)

The file is alldata.abc (I think) it's probably best if you zip it first... but then you could attach it to a post here if you like...

OK.. will do.

Thanks!

The DynoViewer instaler with the latest version of Golden's DynoViewer is available at the usual location...

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

I haven't personaly tried this new version yet... but based on what I've heard it should have all previously discovered bugs corrected...

DynoMoHum is right. The Fantom filename is Alldata.abc.

You can also export individual motor files to the dos format. I'm just not sure how to do it offhand.

Another way is to export it to excel.

I think I'd prefer just to look at the alldata file...

Sorry DynoMoHum, I didn't mean to imply that I was speaking for you.

I was just giving the options for exporting fantom data.

That's alright... I just don't know how to deal with the other stuff... besides if he gives me/us the alldata file I can look at all his motor data and maybe offer some suggestions as to which motor I think is best... Basicly the more data the better... :)

Works for me.

DynoGuru's;

From what I have been reading in recent weeks. I gather that most of you are Oval racers only. With that said, now my questions.
For TC racing, what should I be looking at in the Robi Dyno data when comparing motors. Also would you consider a 1 watt increase in power after some tuning, significant?

Thank you, popsracer

For the most part a motor that works well on a Oval will also work well on a roadcourse, at least in my opion it will.

Depending on what voltage you are testing at, one watt can be more or less significant. I beleive it if you have consistnatly 1 watt more with one motor then another, then it's most deffintely significant. 1 watt of peak power on a 7.5 volt test is less then 1%. One watt of peak power on a 5 volt test is almost 2%, hence the reason I say voltage matters in this. It's all realitive.

My current thinking is that viewing data in relation to AMP input is decieving. I think this is just as true in TC as it is in oval. Data in relation to amp input is more about effciency then it is anything else. Efffciency is important, but not the only thing that's important.

I currently beleive that peak power is more significant then most other numbers. If you use Golden's DnyoViewer looking at the RPM graph, then adjust the gearing to compensate for differnt motor speeds it becomes pretty clear that a motor that has more peak power, also has more power at all other RPM once gearing is applied. It may take more current to produce this power, but it does have more power thougout the full RPM range in just about every case I have seen to date.

To me this tells us that a motor with more peak power will be faster on the track for short periods of time (like on minute or so) then a motor with less peak power. After the first minute lots of other factors come into play as a direct byproduct of effciency, or lack of effciency. Currently I see no way to easliy predict the effects of poor effciency over time. I mean you can make some assumptions that a more effcienct motor will stay fast for a longer period of time, because it wont heat up as much as a motor with very poor effciency... You can also assume that you battery packs will get drained quicker with a motor that has poor effciency, but this is not likely to be much of a factor in modern racing, not when we've got 3300 mAh packs. So... in my opion at this time... peak power is King, followed closely by the Queen who's name is effciency.

RPM is mostly for choosing gears... although I have seen in rare instances where this is not 100% true.

To find the right ballance between power and effciency, I beleive that on track testing is the only way to do it at this time.

If your running with low capacity batterys such as the 1200s and 1300s of days of old, then effciency is much more important then it is today. Spec batterys tend to fall into this class. However I know very few (None) people who use spec batterys in TC, or most other highgly competitive forms of roadcourse racing, or even off road racing.


By the way... if anyone can prove to me that peak power isn't pretty much 100% indicative of general output power across the intire RPM range of a motor, I'd like them to show me how they are doing it...

Sorry I can't give you exact numbers that will tell you if a motor is great or not...

On my Robitronic 60% peak effciency is about the minimum I would play with... even that is pretty low in my opion... Typicaly I see in the neighborhood of 65 to 75 on a good stock motor. 134 Peak power is the best I've seen... 128 is the best any of my own motors have done...(this is at 7.5 volts... 62 watts is my personal best at 5 volts)

DynoMoHum;

Your the man as always. I was refering to a Monster stock that I am favoring in my TC right now. When I first got back into electric TC racing my car was so much slower than everyone elses. I was running a P2K2 at the time. Did all the normal tuning things but nothing ever seemed to make a difference. Bought a Monster stock and swapped it out with the P2K2 and WOW. Now with my Dyno I see about 120w on the P2K2 and The Monster 123.6w after some minor tuning. But I have an OLD Reedy Rage Stock that is showing 122.8 on the Dyno with more Torque and less RPM (this figures). The Reedy was always so slow in my other car no matter how I geared it. This leads me to believe that a Motor with a Higher RPM and similar Power outputs will perform better on the track because of a wider power band. Providing you are geared to take advantage of that.

I gotta do some more tuning to shoot for that 125w mark. When I get some time I'm going to try different endbells and cans together to see if there is any improvement by using one over another.

DynoMoHum --

Here is my file from the Facts II.

There are several Monster motors and a few GM3s in it.

The motor named "MHP PRO" was really strong last night -- TQ and 2nd in the A-Main. Had really good power in the corners.

The motor named "JIMS BEST GM3" was a very strong GM3 in my friend's car -- both were strong.

The motor named "Team1 GM3" is the one that I am interested in comparing to the "MHP PRO" motor in terms of gearing difference.

Thanks

I'm still looking closer at the high RPM thing... for the most part I don't really think high RPM by itself is of any great bennifit... however I don't have enough on track experiance to say this definitively. Theoreticly I see no real advantage to high RPM...


Anyway... POWER is what I know for sure helps...

Goodwrench... I've got your file now, and Golden's most recent viewer... I'll look at your motor data soon.

Still looking at your motor data... I came back to get the info about what motors you were running and which one you specificly wanted to compare...

However the motor in MOTOR TEST is your strongest motor in my opion, and it has better effciency then MHP Pro. MHP pro and MHP 1 are nearly identical... I'd choose the one with more effciency just because it is more effcienct...

If you geared up MOTOR TEST one tooth above what you ran with MHP Pro, it would be even faster down the stratights and have nearly the same power in the corners. If you left the gearing the same, it would be stronger in the corners and nearly identical top speed... However the efficency is significantly better on MOTOR TEST, so it should work very well pretty well either way...

I'm going to try and make a web page to illustrate my points...

I'll go back and look closer at the ones you specificly mentioned...

I think "MOTOR TEST" was actually the dyno run on "MHP PRO" after the TQ qualifying run.

I pulled it out of the car, sprayed it out without removing the brushes and threw it on the dyno. Then I put it back in the car and it was really good in the A-main. I used the same gearing.

That's good... I knew they were very close to the same thing... You must have things setup quite well.. when they come off the track as good or better then they went on, that is a very good thing.

I had Ranked MHP 001 second best, I felt it was slightly better then MHP Pro, but not buy much. If I'm not mistaken gearing should be very simmilar on both of these...

I felt Jim's best GM3 was the fourth best looking dyno run... just slightly better then MHP 003... I'd have to look close, but gearing would not bee more then 1/2 to 1 tooth off of the MHPs...

Team 1 GM3 looks pretty bad compared to your best motors, and even compared to Jim's Best GM3... I'll get bak with you on the gearing... but really don't think you'll ever get it to go as fast as the MHP PRO... not unless you do some work on it...

This all assumes the Fantom is giving accurate data for all motors... I can't vouch for it... but I'm not going to tell you it's wrong... only you can decided if it's giving you informatin you can relate directly to the track... I suspect it does give you data that for the most part translates directly to on track proformance... However, if you rank these motors in terms of Peak power... a list of motors ranked by Max RPM is almost one for one with the peak power list... with the exception of MHP benchmark... that motor does somethign odd right at the end of the dyno run... it jumps about 500 RPM at the last moment... MOTOR TEST also gives slightly lower RPM then MHP Pro, even though MOTOR TEST has slightly higher Peak power...

In contrast I quite often see motors on my Robitronic with significantly lower RPM, yet have equal or better peak power then another motor. So I'm quite confident that this isn't directly related to a Flywheel type of thing... However it may have something to do with the fact that the Fantom tests at constant voltage, and the Robitronic doesn't... I still can't figure out why there are several realatively unexplainable differances in the Fantom and Robitronic data.

It could be that you just never dynoed a low RPM motor that proformed really well... I havne't used the Fantom enough to know if it does happen as often as it will on a Robitronic...

I can understand how the in-experienced Fantom operator might get the impression that higher RPM motors always produce the most power. Most of the time, but not always, the higher RPM motor IS actually making more power with some exceptions. Before Dyno's we used to apply a fixed voltage to the motor and listen to the pitch it produced, which was actually RPM. 9 times out of 10 we were right.Secondly, if you take a real close look at the Fantom time base, peak RPM is not actually peak RPM of the motor at all, just peak RPM over a specific alloted length of time. To prove this, just watch the peak RPM number displayed on your screen while the motor is spinning, then watch the max RPM recorded in the time base. The Fantom stops recording max RPM at a certain point, the point of zero amp draw if my memory seves me right, therefore only recording useable RPM, a very nice feature in my book.The experienced Fantom owner knows motors can easily be tuned with very high power and low RPM, where track conditiond require, like touring car.The myth that the Fantom dyno always produces higher power numbers for higher RPM motors is just that: a myth, and just exposes the operators lack of experience with this Dyno. Please don't anyone take this the wrong way, but you DO have to have a certain minimum amount of knowlwedge to get the most from this or any dyno. After 6 years and thousands of motors I still learn some little trick every week to help tell me which motors will perform best on the track.