Back to looking at dyno output for the pupose of evaluating motors...

take a look at the following, it's a graph of two of Snuffy's best motors (in my opion). They are both monster motors. One is one he called RM-02 and the other is listed as MOTOR TEST.

I've used Mike Golden's "DynoViewer"(TM???) to display these two motors in relation to amp input.

Here's the graph...

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


I think the choice of these two motors is not a easy one to make. Motor one has peak power of 64 watts, and Motor 2 has a peak of 65 watts... advantage Motor 2... However Motor one only uses 29 amps to produce it's 64 watts, while Motor 2 uses 32 amps to produce it's 65 watt peak. Motor 1 puts out more power bellow 30 amps then Motor 2, and vica versa... I honestly do know know how to choose between these two motors. I think it's a very interesting study in motor choice especialy if your averaging 30 amps during your race.

Anyone else have ideas on which of these motors is better? and why?


My guess is that Motor 1 had realitively light spring on it, realitive to Motor 2 that is... However it could be something else causing the lower RPM and higher effciency...

By the way... here is a graph made with Excel of the same two motors, in the same format (in relation to amp input). It took me a heck of a lot longer to make this graph then it did to use Mike's DynoViewer to view it...

http://www.wiltse.net/images/rm2_motor.gif

My graph is pretty nice, but Mike's dyno viewer is really slick.

Here is a link to the DynoViewer.

I originally wrote it to compare gear ratios between 2 motors. The "Load From File" loads Robi .txt files, and the "Load From Clipboard" loads the Fantom's "Timed Based Data" from the clipboard.

As it turns out this program works great for viewing Fantom data with relation to Amps.

This is Free software that I wrote. Anyone may use it as they like. Of course I will maitain the Copy Rights :D, but that doesn't mean much.


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

Mike's software really is pretty cool, espeicaly for viewing the Fantom stuff... His gearing change/viewer feature is something that the Robi doesn't have, so if your trying to figure out what happens if you gear things a certian way, his viewer does something that you can't do on the Robi or the Fantom as far as I can tell.

I'm still playing with his gear slider, in an effort to see just what the possiblitys might be in gearing a motor differntly to make better use of the power/effcinecy of a perticular motor. It's not always as cut and dry as one might think.


I put up Mike's viewer on my site just as a public service. The site Mike had been using didn't allow files bigger then 2M, and his package was just over that limit. He had to break it down into two or more items on the site he had been using, so I offered him a place to put it in one chunk... I certianly make no claims or warrantys to his stuff... (other then it seems to fill a need for some dyno users out there)

For what it's worth....

I was observing some of Big Jim's discussions on dynos recently. He appears to have clarified his comments about the Fantom giving High RPM motors favor over lower RPM motors. I don' t beleive I've ever seen him make the comments so clearly preiviously. Having read his recent comments, it seems it's likely the Power Factor numbers that he doesn't trust.

At this point I would tend to agree. From what I have seen, the High, Medium, and Low power factor numbers seem odd at best. Mostly what I've observed about them is that there can be two differnt motors with clearly differnt power output when viewed in relation to amp input, yet the power factor numbers are nearly identical.

Does anyone have a clue as to how Fantom figures High, Medium, and Low power factors? My suspesion is that it's somehow relating power to RPM... If this is the case, then it would surely make a high RPM motor look best, that's just the nature of how things look in relation to RPM... Unless a motor is just pure junk...

I had an brief opertunity to do some testing on a Fantom dyno this weekend. Unfortunately I couldn't get the data directly on to my computer. I did write down some of the numbers that I thought might be most helpfull to me.

I dynoed a EX-Street Spec motor that I know is a very good motor, and I also dynoed a Paradox handout motor that I know is a average at best stock motor. On the Fantom the EX-Spec motor did show up as being better then the Pardox, but only by 3% (based on peak power).

When I got home I dynoed the same two motors on my Robitronic dyno. On the Robi the Ex-StSpec motor shows 18% better peak power. This is with the 5 volt setting on the Robi.

I intend to run both these motors on the CE TurboDyno 45 tonight, to see what it says...


I find it extreemly stange that there is such a huge differance between the power output of these two motors when viewed on two different flywheel dynos. I could understand if one dyno was putting out slightly higher numbers but both motors showed the same level of increase... but when the differacne between the two motors goes from 3% on the Fanto to 18% on the Robi... makes me think that one of these dynos is not very accurate...

I did not do any on track testing with these motors to see what happend in that regard. That will have to be a future test.

I can say that in the past I've always been able to back up my Robi data with on track proformance. I also have been able to see simmilar realitive proformance differances for motors when I dynoed them both on the Robi and the CE TD. So... that leads me to be more suspiscious of the Fantom then of the Robi... I will do more testing and keep you all informed of what I find.

I think I need a expert driver to run a EX-Spec motor and a Paradox... to get me some on track data...

Either way... I think something is very strange... I just don't know exactly what it is.

Hey guys;

I just curious what would cause one motor (everything being equal) to be a "DOG" and other to be a "ROCKET". I would think that the Armature would have more variables to cause this than the Can and Endbell to cause so much difference in performance between two identical motors.
Any thoughts on this (PLEASE don't tell me to do a search)

Thanks, Popracer

pops I have found quite the opposite. The thing that matters most of course is the condition of the comutator and brushes but right after this is the proper alignment of the brushes in the endbell and that is what most people over look.

I have done ALL of the recommended tuning options to this motor and nothing seem to work. I have all of the tools needed to maintain and tune motors (except a Dyno) EVERYTHING is Aligned, broken in, seated and trued as per: Big Jim, Fantom & Trinity websites.

I suffered with this motor for several months of racing (P2K2) before trying another one in my car and what a difference. Exact same Motors tuned the EXACT same way in the Exact same car with the Exact same gearing.

That's why I am asking. Is there someway to tell in the package just by looking closly or is it just luck of the draw on motors.

Thanks, Popsracer

At some point all three play a role. Can, arm, and endbell. I honestly do not know which is more important.

I do know this... I have one EPIC endbell that I can put on almost any EPIC arm/can combination and I often see 2 watts differance in the proformance vs. when I use a differnt endbell.

I have tried to figure out just what makes this one endbell work so much better, but I can not figure it out. Once I realised this, I stoped trying to do extensive dyno testing of differnt model motors unless I could use the same endbell. I feel it's a unfair test if I use other endbells and then try and say... motor A is worse then motor B...

I have also seen noticeable differances when exchanging only the can, or the arm in motors. I just don't have good data that I could say for sure how much your likely to see. I think if you have 5 motors and want ONE good motor you would systematicly take each component and test it aginst all the other components... find the best components and combine them to get one hot motor. This too could be problematic however... because at somepoint one can may work well with one arm, but not work well on another arm etc... I supose the same can be true for endbells...

IF you could trust the seller of the motor to provide accurate dyno results you could tell alot about a motor. However you often CAN NOT trust the dyno data given by some of the biggest names in RC motors. I'll try not to name any names... but company T used to use Robitronic dynos for their lables, now they use Fantom... I have NEVER seen a company T 'pro' motor with fully seated brushes.

I know for a fact that unless the brushes are fully seated, a dyno run means absolutely nothing. This is because the motor will run MUCH differntly once the brushes are fully seated.

Company T is not the only company I don't trust in this area... just an example of one...

If you find a small motor tunner, then you are much more likely to get a dyno lable you could trust...

My general problem with even smaller motor tunners is this... What's the likely hood that I get a REALLY HOT motor from one of these guys? Arent't they very likely to keep the very best motors for themselves? and/or their sponsored drivers. I'm a natural born skeptic... so I like to tune my own motors, and I suspect I'm just as well off picking a motor randomly from a batch of un-touched motors directly from Japan.

Either way... never trust dyno data taken from a motor that is not fully broken in.

TMFU; (what does tmfu stand for?)

Thanks, Your response was what I was hoping someone would be able to provide. You just gave me another reason to buy a Dyno.
I had read somewhere awhile back that there was something to look for when selecting motors in the LHS's. But I wasn't into electric r/c then so I didn't save the information.

Popsracer

TMFU stands for "The Man From Utopia"... my computer work station is named 'utopia'... and therefor I am from utopia... and a man... so...

I really should ask Hank to change my name. Too man people assume bad things about TMFU... One person was certian it has something to do with company 'T' and four letter words that are not very nice... It has nothing to do with RC or company T... It's a refferance to a obscure Frank Zappa album titled... 'The Man From Utopia'.


Even if you trust dyno lables... takes a fair amount of knowlege to interpet one... Most often all that is given are 'peak' numbers. Peak numbers are of minimal value by themselves... If I had to choose one single number that is most important I'd say EFFCIENCY. Many people would disagree with that... but my reasoning is this... Effciency is the only way to achive more POWER... if a motor is not effcient it will never use the input power effectively... Still... Effciency by itself is not all that usefull.

If I was to pick a motor by using only one number it would be peak torque.

I agree the best stocks that I have ever had were ones that were untouched. ESP sold me quite a few "tear down" motors without brushes springs etc. In the end they probably cost me a bit more but they were well worth it.

Greetings everyone,
I recently got a used robi dyno, and I would appreciate tips on what to look out for.

I tried it on my race motor, a Tamiya "Super Modified 11T" (11x2 arm). Basically tested various timings. The odd thing about this motor is that the maximum power output reading as well as the RPMs stay more or less similar. Only when I up the timing, the efficiency goes down and the spool up time decreases. This happens till about 20 degrees. If I hit 24 degrees the spool up time goes down quite a bit. So I choose the timing with the best spool up time.

Whereas on my bashing 23x2, every time I up my timing the max effciency and max power actually goes up! But decided to hold back to run only 22 degrees.

I did not compare the other screens on my dyno because, frankly, the information is overloading me :eek:

On the track though, the dyno seems to bear out. I get much better pick up (and I can gear up further) by picking the timing which gives me the best spool up time. Seems like the robi is a pretty good investment.

Do appreciate you guys thoughts on this.

Thanks!

Regards,
Alvin

A poorly aligned brush hood can drastically affect motor performance. And, with folks messing around with brush hoods, they have a higher risk of causing more harm than good.

Personally, I feel a lot of folks should not be messing with brush hood alignment. For the majority of Trinity based stock motors I have found them not to require as much brush hood alignment as Reedy based stock motors.

I've found on Epic based motors that just having the brush hoods in line with each other and centered to the comm that the motor works just fine in conjunction with the brushes properly broken in.

No need for anyone to tell me that having the brush hoods properly aligned gets max power out of the motor and that sometimes means they are not lined up with each other.

I am just saying that for the majority of club racers they do _not_ need to go through that lengthy process of messing with brush hoods.

I am a fairly experienced racer and an okay motor tuner (I tuned the motor that TQ'd stock touring car at the Cleveland Champs last year). I had a case where I adjusted the hoods on a motor where I thought the hoods were properly aligned. I threw the motor on the dyno and the power numbers were about 8 watts lower all around from where they should be and the over all motor stats just sucked. On a whim I used my rod and bar alignment tool in the motor, made everything parallel/in-line, threw the motor back on the CE dyno, and got 103 watts at 20 amps (7V fixed).

Proper brush break-in is a lot more important. Too often I see folks just breaking in new brushes for 300 seconds. Sorry, the time for break-in depends on the type of brush (re: how hard the brush is). For the 767s I run, I have had to run the motor for over 1500 seconds at 3V before the brushes were completely broken in.

Anyways, Popsracer, if you aligned your brush hoods on the one doggy motor, I would start by aligning the brush hoods so they are in-line with each other and the bushings (hopefully you have a rod and bar type alignment tool), put new brushes in, break the brushes in, and see how the motor feels.

btw: not all motors can be geared the same -- even the same type of motor with the same brush/spring setup.

Anyways, those are just my opinions.

-Rich



Originally posted by popsracer
I have done ALL of the recommended tuning options to this motor and nothing seem to work. I have all of the tools needed to maintain and tune motors (except a Dyno) EVERYTHING is Aligned, broken in, seated and trued as per: Big Jim, Fantom & Trinity websites.

I suffered with this motor for several months of racing (P2K2) before trying another one in my car and what a difference. Exact same Motors tuned the EXACT same way in the Exact same car with the Exact same gearing.

That's why I am asking. Is there someway to tell in the package just by looking closly or is it just luck of the draw on motors.

Thanks, Popsracer

For the most part I concur with Rich. My best motor/endbell is one that I never touched. It's one that came direct from Trinity with pretty good alignment, so I never fiddled with it. I have ruined as many bursh hoods as I have made better... I think I've gotten better at it after doing it 20 or 30 times... but still tweaking a brush hood can be a tricky thing. I have not really experiemented with in line with the arm shaft vs. wear marked down the center of the brush, but I have no reason to doubt Rich's experiance... I personaly know Rich... and what I know of him, gives me even less reason to doubt his experiances... (I also have no doubt that he's as good or better at tunning a motor then I am...)

I totaly agree with Rich's comments about gearing. Each motor is differnt, even between the same models. I've got data that I beleive proves conclusively that just changing springs on a motor can make the RPM change enough to warrant a gear change. This seems espeicaly true with todays high RPM motors like the GM3 and Revenge of the Monster.

All of this points me in the direction that a good dyno is a very usefull thing... but you must learn how to use it. You can acomplish the ultimate goal with on track testing, but in my opion that will be a VERY long procedure without some dyno data to help... depending on your driving and set up skills, you may never be able to relate motor proformance directly to on track proformance. Too many variables that can happan on the track... miss a turn by a inch or two, etc...

Back to hood alignment... one reason I have had doubts about using the wear mark down the center of a brush to determine ultimate hood alighment... What if the contour of the brush is not centered exactly when you start your hood alignment procedure? If the contour is not exactly centered on the bursh you start with, the wear mark would not be centered either. It would be VERY hard to verifiy if the contour of the brush is centered, without some really fancy equipment.

New findings on my quest to find out more about the Fantom dyno...

I ran my Ex-Spec motor and the average Paradox motor on my CE TurboDyno last night. I never really quite found the Peak power output of the EX-Spec motor... I went as high as 40 amp load, and never found the motor to drop off in power. It had reached 106 watts at 40 amps, with voltage of 5 volts. The Paradox reached a peak power of 84 watts at 32 amps, 5 volts. So the differance in peak power on the CE is at least 26% in favor of the EX-Spec motor.

Review... The differance in peak power on the Fantom was about 3%... On the Robi the diff was 18%... both in favor of the Ex-Spec motor...

So... based on peak power alone all three of these dynos show the Ex-Spec motor with more power. That's a good sign...

However I have serious concerns about the small margin of differance on the Fantom. I have stock motors that are at least 5% better then this Paradox. I have a very strong suspiscion that it would be very likely that a good stock motor may very well show up as being stronger then this Ex-Spec motor on this Fantom dyno. I am 100% certian that neither my Robi or my TurboDyno would ever find any stock motor that could exceed the power output of this Ex-Spec motor.

I beleive there is something wrong with the Fantom dyno... At the very least there is something very odd with it and the 'facts' it reports to it's users. If I get a chance I plan to investigate it further...

For anyone who is interested... I've made a web page with dyno data for this Pardox and Ex-Spec motor... It's got data I collected from a Fantom, my Robitronic, and my TurboDyno. I changed nothing at all on the motors between dyno runs... I have added commentary along with the data... I'd be happy to hear anyone's comments about what might be happening and why...

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


If anyone knows how the High, Medium, and Low power factors are calculated on the Fantom I'd really like to hear about it... Based on this data... I can't make heads or tails of them.

Rich Chang;

The P2K2 in question was a "Pro" version. I ran it one race and was not happy with the performance at all. I disassembled and inspected, decided to do all of the checks/maintenance that is normally done between race days.
The Hoods were aligned with a Stick through the hood only. I could not find the kind that goes through the bushings too, so i had to settle with the standard tool. The used Brushes look "Perfectly" aligned to the Com when examining wear marks.
If I gear the motor for top speed at the end of the straight. There is NO punch in the corners. If I gear for punch, then top speed suffers.
What really told me that this motor is a DOG is when i replaced it with another P2k2 and applied the same tuning to it. The second motor is a rocket. Exact same type of motor, same tuning, gearing, everything. I suffered with this motor for several months of racing thinking that the problem lye elsewhere. NOW with just a motor change my car is competitive with the other cars in my class.

Thanks, Popsracer

I posted under the topic "Electric Motor Dyno help " how I understand the Fantom dyno calculates numbers. Post is too long to put here too.

When the "Fantom" was an "RSR" dyno many years ago, I sat down and calculated/reproduced the numbers for the dyno screen, so I'm pretty sure I did that right. The one number I was off a little on was the moment of inertia of the flywheel. It seems Fantom makes a correction to the flywheel inertia number for "earth torque," (i.e., the earth is also spinning) which I didn't have a value/calculation for.

I read your post on the other thread... I don't fully understand your comments about the power factors, but I kinda do... I started to assume they had something to do with RPM... but reading your discription it's not exactly directly related to that... Anyway... thanks for the comments your the first person that's commented about the Power Factors at all...

As for the Fantom's Torque numbers... at one point I was convinced that they some how calculate a 'realtive' torque... that is it sort of seems that they give each motor 100 (or 98) as the maximum torque which occurs at start up, and then torque reaches 0 at max RPM... This may be exactly what they are doing, I don't know for sure... I do know there torque numbers seem a little odd.

This is the first time I've heard of 'earth torque'...

I think what the Fantom gets that others do not is the motor's own moment of inertia. I can see how a more lightly built ROM would look better than a P2K or whatever, even though the power curves at a more steady state would be equivalent (as we've seen). I'm not sure how well this will translate to car performance. A motor with a light arm and a small pinion might have less inertia but it has to get to a higher RPM to make power.

I am going back to the idea that the Fantom is comming up with Torque numbers that represent 'realtive' torque. Realitive to Maximum for that perticular motor.

At this point I went back to Snuffy's Fantom data... I looked at MOTOR TEST (a new Monster), and a motor listed as FRP2K-01. I've taken the data from the clipboard and pasted it to Mike Golden's DynoViewer... For both of these motors, torque starts out at more or less 95 and goes sperate ways from there...

I bascily NEVER see this behavior with Robitronic Data... Especialy when you have two motors with such differnt max RPM.

I am about 96% convinced that the Fantom is comming up with something that I would term 'realtive' torque. If this is true... then it would likely go a long way to explaining the behavior I was seeing with my Ex-Spec motor and my Paradox when I recently tested them on a Fantom.

RWB the Correllieous (I think i mispelled it) force from the earth rotating is so small that it would be negligible. Anyways if it wasnt it would matter if your dyno was pointed north-south or east-west. And since we are taking a relative measurement anyway why would they include this? Nobody is racing out in space on a stationary platform.

Pat:

The explanation of the earth torque correction is directly from Dave C. himself, who wrote the program.

Latest findings on the Fantom 'Facts'...

I've figured out why the Fantom torque numbers seem to be inconsistant when trying to reverse engineer the value for 'JM' talked about earlier.
It seems that Fantom is using the acceleration numbers from the next time period to calculate torque for the present time period. That is...

If you look at the numbers for .1 second, the torque values for that interval are derived from the increase in RPM listed for the .2 second interval... the same is true for each time interval afterwords...

As reported earlier Fantom also uses the current value of RPM in their 'power' calculation. From what I have read average RPM for the time interval should be used.

If you go through and caculate numbers for Torque and Power using the the average RPM and actual accelertation for the present interval, you tend to get higher output power numbers, and the effciecy numbers also increase as one might expect. The numbers start to resemble those that can often be seen on a Robitronic or TurboDyno.
(that is effciency starts to go up to at least 60% at it's peak for a good stock motor)

I have no idea why Fantom is doing what they are doing. Near as I can tell what they are doing is wrong. Based on Snuffy's Fantom data the error is not all that great when you compare it as it relates to potential differance between the most favored motor vs. the most handicaped one. Perhaps 1% at most on all of the stock motors Snuffy had given data for. It seems that this does favor higher RPM motors... I haven't figured out exacly what the worst case senerios would be, but I do know that any motor that has a sharply declining Torque slope will be handicaped by Fantom's methods. On the contrast a motor with a torque slope that doesn't decline as rapidly will tend to show slightly improved power numbers over much of that motor's power curve. As I say... I have no idea why Fantom would do this. I don't know if it's just a plain old mistake, or if they for some reason feel this is the right thing to do and have reasons for it...

I do know that the Competition Electronics TurboDyno that actualy measures Torque and can use fixed 5 volts for testing, does not agree with Fantom's methods and/or 'facts'. Personaly I would tend to beleive the TurboDyno's results more willingly, simply because there is very little that could be wrong with their method of determining power output and/or effciency. So... based on what I have seen, I can't help but think that Fantom is doing something wrong.

Now, I still haven't fully been able to explain what I'm seeing when I dynoed my EX-Spec motor and compared it to a average Paradox motor. At this point I can't prove with math that Fantom's 'Facts' would be off enought to cause the very small margin of differance seen on these two motors. I still don't have ALL the numbers from my Fantom test of these two motors, so I have been unable to do an extensive analysis of the dyno runs... I really do feel that it is very odd that the margin of differance on the Fantom is only 3% on these two motors, yet on the Robi and TurboDyno it is at least 18%... I really want to find out why.


Meanwhile... The way Fantom is doing things seems to discurage certian motor tuning techniques... It makes me wonder if people who use Fantom 'Facts' machines are tuning motors in ways that make them look better on a Fantom, but actualy are not living up to their true potential. This would seem to be especialy likely whith high torque motors like the P2K and even on other motors like the EX-Spec with it's realtively low timming... Things that ussualy make a high torque/low RPM motor run better, may show up as being a bad thing on a Fantom... This may account for one reason some companys seem to think their newest High RPM motors are somehow better then their older lower RPM motors... At best... I don't trust Fantom's Facts machine as much as I do either the Robitronic or the CE TurboDyno and I'm getting closer to figuring out exacly why...

I'll soon post my Excel spreadsheet that has some of the calculations and such that has lead me to the point I'm at now.

RWB either they are feeding you a major load of BS or they have no idea what they are doing.

More and more I'm thinking maybe both are true when it comes to the Fantom Facts machine...

From what I've seen, I think the problems could be corrected fairly easily however... unless I find something further to question...


ALso...

RWB... I've tried to use your info on the Power Factor numbers to figure out how they are calculated. You may very well be on the right track, but at this point I've not come up with what I consider to be the actual method used to calculate high, medium, and low power factors that Fantom gives. I must say... these power factor numbers seem to be almost worthless, and quite possibly very misleading... I really wonder why they were included at all in the dyno output of the Fantom.

I have a question guys -- it seems that in scanning through this thread, there is a lot of negative comments about the Fantom dyno.

Yet, at our track, and at the recent ROAR Region 5 Oval championships, the Fantom was the ONLY dyno you saw there. NO others -- no Robotronic, no CS.

These guys are factory drivers and could have whatever they wanted. So why are they all -- 100% of them -- using Fantom dynos ???

Thanks for clearing this up :)

Pat:

I've sometimes wondered if there were some fish stories to some of that...

TMFU:

The low/mid/hi power numbers were somewhat useful when stock motors were "slower" (i.e., spin-up times of 3+ seconds??). One track we ran at years ago was a 100+ ft drag race with 180 degree turns at either end. You almost came to a complete stop before turning. In that case, you tried to get the low and mid range power numbers up (more or less just some guidance). Another track was so smooth and fast you just tickled the throttle to set the chassis (if you lifted at all). People were always looking to maximize the hi power range numer for that track. In these cases, the power range numbers were easier to understand that trying to figure out spinup times or portions of spinup times (which the program doesn't calculate). If you look at these as guidance numbers, rather than absolute numbers, they do ok. Perhaps these numbers are now outdated if most people today have a better understanding of power bands and how to tune within/to a given power range.

There's something else you can do with Fantom that you can't (at least I haven't figured out how to) do with the CE. If you look at the tail of the RPM vs time (??, it's been a while since I've done this, but I think that's the right screen) curve, it should be smooth. If it has bumps, its's a good indication that there is brush bounce, need higher pressure springs or smoother comm. So again, this is great for 5 volts, and if they do convert to 7 volts, this could also be a useful indicator for 6 cell.

I'm not an oval racer but I'm pretty sure Oval racers primarily care about RPMs?

From what I have found (like what Glenn said) RPM motors look much better on the Fantom dyno. Torque motors look better on the CE dyno. That is my experience (and it was tested many times this past weekend at the US Indoor Champs at Cleveland).

So, the Fantom dyno seems much better for Oval racing than a CE dyno would be.

However, as long as you know how to use the data and gear accordingly, one can win with either dyno.

-Rich

Teamgoodwrench,

From what I understand at this time is that the problem is that Dyno and Pat just can't see the logic in the Facts numbers. (BTW I don't either).

That's the reason why they are discussing this.
They are testing and trying to figure this out.
Someone who's just bashing, wouldn't go through that much trouble.

But Teamgoodwrench, maybe you can shed some light on this item.
Can you explain these numbers?

Or maybe you know someone who could respond to this thread and shed some light on matters.
Participate in the discussion!


Regards,
Pizza

Thanks for the posts!

I just got a Fantom, so I'm a newbie with it I'm afraid.

From what I've seen at the track, the guys are looking at the power number primarily and the RPMs second.

After that they are using the DOS version of the software to get the required rollout using the track record as the target lap number.

I haven't seen them using the Windoze version of the software at all.

From my perspective I'm just simply trying to understand the Fantom Dyno and the numbers it gives. I have heard negitive things about it for a long time, but I'm trying to figure it out for myself and trying to report the facts about what I find. I find that if you look on the surface it's numbers are just not very beleviable... Especialy it's effciency numbers, they are WAY lower then what I've seen with other dynos. This alone just doesn't make sense...

I have looked at Snuffy's Fantom data quite extensively and I see what I beleive are obvious flaws in the data and/or how the data is represented. At this point I would clasify the flaws as being somewhat minor... however I also have concerns that the flawed data could quite easly mislead you into thinking that tunning for HIGH RPM is the best thing to do. I don't see this with the Robitronic or the TurboDyno.

As for oval racers, and their use of the Fantom and/or high RPM motors... well maybe they go hand in hand... If the Fantom tells you that high RPM motors are better then Low RPM motors, then the likely conclusion would be that Fantom users would prefer high RPM motors. However the fastest oval racers in my area only play around with the Fantom... They also use the CE and it's my belief that they put more trust itn the Turbodyno then that do the Fantom. My sample is very small... and maybe strictly a regional thing...

I personaly beleive that ANY of the current EPIC motors are fully capable of putting out huge peak power numbers these days... THis includes the P2K and Paradox motors... Most people buy the newest motors, simply because they are the newest thing and people like to try them... I also still know fast guys who use Paradox motors at times...

One of the most interesting things I've heard recently about the Fantom is that the local fast Oval guys are not at all impressed with the gearing features of the Fantom... for years I have heard nothing but praise of the Fantom gearing thing... So I found this really odd that the local guys don't think much of it.

Anyway... I really am trying to give the Fantom a fair evaluation... I'm not trying to purposely slam it or give it negitive comments without cause. I'm just reporting what I've found. At this point I personaly wouldn't buy one if I needed a new dyno. However if it was the only dyno I had available, I beleive I could make sense of it's data one way or another. I do beleive that it's current software is flawed and could could likely be made much better with a few realtively minor changes.

I'm going to ask Mike Golden if he will modify his DynoViewer to calculate Torque, Power, and effciency they way I beleive they should be calculated... Perhaps he will make it so that you can see Fantom's numbers or the numbers I feel are more accurate... If Mike will do this, then I would likely use his softare to view Fantom data if I ever had to use one as my only source of dyno data...

Just for fun, here is the CE dyno sheet for the 1/12th motor I ran this past weekend at the US Indoor Champs.

This motor ran like a charm (I was 2 seconds ahead of TQ in the 4th round with less than 2 minutes to go before I got hit by a back marker and a crappy solder joint I made gave way and the battery pack came apart).

This motor looked like crap on the Fantom dyno. On the Fantom dyno it barely had 51 watts peak power.

-Rich

If anyone want's to see the Excel spreadsheet I've been playing with to figure out what Fantom is doing, they can get it here...

www.wiltse.net/zips/facts_III.zip

Sorry but there's not really and comments in it... but if you looke closely you can see the formulas I'm using and can see some graphs that represent Fantom's data compared to my data... On the graphs I currently have I've used 'relitive' numbers for the Fantom numbers... What I mean is I've made the Fantom's peak power numbers for Snuffy's best motor equal the peak power numbers I caclulate for the same motor. All other "rel" numbers are realtive to this motor... You will see that some of the lower RPM motors get a boost from my calculations, and the location of the peak power changes... It's my beleif that my numbers are more accurate.

I didn't include Fantom's torque numbers on the graphs... mainly because they basicly mirror my numbers, except for the fact that they are off by .1 seconds on each occurance...

Which version of the Fantom software are you guys saying is "flawed" ?? The DOS version or the current Windoze version ??

Or both ??

Thanks

I am working with the Facts II data... At this point I have no way to get the data from the DOS softare... however based on the fact that the DOS software also gives very simmilar power and effciency numbers, I would conclude that it too has the same flaw in it.

I'm not sure anyone else here is going as far as to say they see flaws in the Fantom data... Some are pretty much backing this up with there comments, but I have data that seems to indicate there are indeed flaws in the data and/or the way it's reported.

Over the years there have been many people make very vague claims that the Fantom is flawed... Not many people have given data that directly supports there opions however. My analysis of the Fantom is about as extensive as I've ever seen in this regard.

So... I'll raise the question again. If it is indeed "flawed", then why, for example, did ALL (100%) of the ROAR Region 5 Oval Championship drivers last month (factory sponsored and all) rely on the Fantom dyno exclusively ??

I'm confused.

From what I have seen with Snuffy's data the flaw I see only changes the peak power by a 1 or 2 percent. When I compared Snuffy's highest RPM motor(and best overall motor) to his lowest RPM motor, the flaw is responsible for like 1% or very close to that in favor of the high RPM motor. This is a very small amount...

However it is significant in my opion... because the way it shows up... If you have a naturaly torquey motor, and you use the Fantom to tune it, it's going to tell you to tune it in a way that is not likely to put out the most power for that motor.

Peak power is KING in Oval racing... Many new motors are fully capable of putting out large amounts of peak power... If you go to a race with handout motors, the flaw may not even show up... since the nature of all the motors used is going to be simmilar, quite possibly may become a non-issue... especialy to a knowegable racer...

And the simple fact that these top level drivers likely use on track results more then their dyno...

Why do they use the Fantom? I don't know... you'll have to ask them... however in my opion they'd get better data from a CE TurboDyno or a Robitronic Dyno...

It could be that they dont know any better and it really doesnt mater that much anyway (maybe we dont need dynos to go fast hmmmm).

I base nothing on what "everyone is doing. I just bought some batteries from a national caliber racer...this guy is in the A all the time at oval races. The packs looked like a 10 year old built them. They are great cells but if you put them together like he did you loose any advantage that you get from the great cells. (You know who....if your reading this I didnt mean to offend you, the batteries themselves are great.)

The fact is most racers don't understand how these things work and basically put faith in a "magic box"

You know what I find really quite funny (or maybe quite sad) is that one of the biggest motor makers in the world has switched to the Fantom dyno... I don't think they do much factory Oval racing however, so they are not likely the sponsers of the racers Team Goodwrench has observed.

Now as I say, the error in the Fantom data is quite small... however for me when I tune motors I'm extreemly excited if can find a 1% increase in power... so when there's potentialy a 1% error in the data under certian condtions I find this totaly unacceptable for myself... I guess I'm just too much of a perfectionist...

Which motor maker are you referring to ?

I beleive they spell it TRINITY...

They used to use Robitronic to make lables for their 'Pro' motors. A few months ago they switched to the Fantom.

I asked why they switched on their techtalk forum... I beleive part of the answer was... 'the dyno test takes less time'.

I have to wonder how much of their motor design is based on the Fantom numbers... They seem to be leading the parade of high RPM stock motors.

A dyno doesnt make you fast it is just a reference point,I had a Turbo dyno for a long time and I now have a Fantom.Neither one is perfect.I never even considered a Robitronics mainly because I worried about service and no one I know has one.
Mainly I look at specific amp draw on the Fantom but the oval gear calc is a useful thing if you figure out how to relate it to a paticular track and your driving style.
Find a motor combo thats fast on the track and use it for a reference point for stock motors thats about all there is to it.


Teamgoodwrench,If I were you and I had all those guys to race with that were at the Region 5 race I would ask them about the Fantom,
Shwambeck,or Danny D,or almost anybody else that races at Trackside can tell you more than you will ever learn on this thread.
Cant wait for the nats in april,great track.

Hoopd,

I think everybody on this thread is pretty open minded.

So would you be willing to talk to those guys and let them inform us on the ins-and-outs af the Fantom.

As for Teamgoodwrench,
If all your other club-mates use this dyno you probably did the right thing in buyinmg this one.
They should be able to help you out guite good.


Regards,
Pizza

You definitely get a lot more data (at least from the DOS version) from the Fantom than you get from the CE dyno.

-Rich

Hey -- just getting ready to fire up my Fantom for the first time. I don't have a manual with it -- there are 2 sets of red and black wires on the right side of it. Do the both go to the battery/power supply or ???? One set is shorter and heavier guage wire than the other set. Both sets have alligator clips on them.

Thanks !

The longer leads hook to the pwr supply,the other two connect to the motor.Make SURE you dont hook up the pwr supply leads backwards or you wont get a chance to use it.