For some reason, water dipping doesn't work as well on the new brushes. It takes a little longer. In the old days, you would only dip the motor for a few seconds.

Want to speed things up? Add some salt...just clean it out after.

Pepper too?

Nah, that just makes you sneeze. Hot stuff, Texas pete raises the temps though ;) ;)
:lol:

Just helps the water conduct...:p

Well, I took some time and played with thee old dyno last night...

Started out wanting to explor spring tension some more. I also played with voltage a little...

My spring test sort of started out where my other older spring test left off. The lightest springs I used this time were like 7 on the fiddlestick. Those were some new greens I recently purchased. I had reds that were 8, and purples that were 9 fiddle stick units. THe stiffest springs in my old test were 7.5 on the positive, and 7.0 on the negitive side...

My new test was not nearly as dramatic as some of the results I observed on the older test. Basicly the green springs had slightly less RPM then did the red springs, power was very simmilar. Purple springs were almost indistiguishable on the dyno from the red springs.... This was all on a Monster stock motor with brushes that had the Trailing edge trimed and a H-cut... I did some testing at 5 volts, and more at 5.5 volt setting on my Robitronic dyno.

Probably the more interesting part of what I did last night was when I started playing with voltage increases from 5.0 up to 5.5 in 0.1 steps... The inrease in peak power appears to be somewhat logarithmic, rather then linear. There probably is some perfectly reasonable explination for this, it may be as simmple as the fact that peak power moves toward higher and higher amp rates along with the increase in voltage.

For example... on this perticular motor with two red spring on it... at 5.0 setting, Peak power was about 59 watts, at 5.1V it was about 60, 5.2v was 62, 5.3 was 64, 5.4 was 68, and finnaly at 5.5 volts peak power output was around 71.

What does all that mean? Well for one thing... the more voltage you have, the better off you are. But basicly you can't do much about that with motor tuning, so you left with finding better batteries, speeed controls, and wiring to get improvments there.

It may come as very little surprize, but spring tension around the level of a red spring is about as good as things get for a 4 cell type setup... Purple doesn't seem to be much differnt howerver.


Also... at 59 watts at 5 volt setting... my Monster still doesn't really run all that great... not terible, but it's certianly not my best motor (62 is a good motor, 64 is the best I've ever seen) I do know however that it seems to do quite well at higher voltages, at 7.5 volts it proforms about as well as any motor I've ever had. But this is somewhat unrelated to springs... I don't know what I could do to make my Monster work better at 4 cell voltages... I'm still trying to figure that out.

Dyno,

You might want to try running the same test with a different motor (GM3 or whatever). Just from what I've heard, the ROM seems to be good in 6 cell but not as good in 4 cell. Oval might be a different story but you might want to look into it.

Dyno, there is a reason why the power out increases like that. The answer electrically is that V=IR, where V = voltage, I = Current, and R = Resistance. By that equasion, you should be able to see that holding the resistance constant and increasing the voltage, the current through the circuit will also increase proportionally the same. So, if you increased your input voltage by 10%, then the current in should also increase by 10%. And because overall power in has increased, power out should have also increased.

I don't know the current you put into the motor, but the generic equasion would be (New_Voltage / Old_Voltage)^2 * Old_Power. The "^2" means Squared.
Using your numbers (5.4 / 5.2)^2 * 59 = 68.8 Watts. Its a little off, but the efficency has changed.

Hope that helps.

Also, people have recently been talking about the new GP cells that have that 1.17 voltage over the usually 1.15. Lets find the difference in power for a 6 cell pack. I'm assuming a mod motor that puts out 200 watts.

(1.17 * 6 / 1.15 * 6) ^2 * 200 = 207

Thats a 7 watt increase.

If it was a 100 watt stock motor, it would now be 103.5, and a 3.5 watt increase on a stock is very noticeable.

Also consider that actualy some of the older GP 3300s were 1.13s with average being about 1.14 just a few months ago... I've heard of 1.178s being availble to people who are not even sponsored...

Now is .01 volt per cell worth X dollars? Only you can decide... but if someone tells you voltage doesn't matter, there confused or trying to mislead you...

Of course then you also get into that old battery debate of wether run time or voltage is better. However at some point it doesn't matter that much... a 1.141 420 second cell is not as good as a 1.178 420 second cell... and it will make your motor run better too...


I know for sure my Monster doesn't run as well at 5 volts as it does at 7.5 volts... I have seen a couple Monsters that looked pretty darn good at 5 volts... (better then mine anyway). Next chance I get I may do a simmilar voltage test with another motor just for kicks...

Keep in mind that unless you can somehow look at the discharge curves, a 420 with 1.165v might actually be even voltage or possibly higher to a 390 with 1.175v as far as actual voltage that you motor sees in a run. Of course a 420 1.175v will be better than a 420 1.165v. Batteries with 420 and 1.145 for me seem to run equal 390 1.155v. Runtime and voltage together = King. Just some thoughts.

Paul

with the fantom dyno what are some things to look at when tuning stock motors? what are good numbers and where shoul i look for them?

I know this is going to "stir the pot", but I felt this was the proper thread to post this... I have always been a believer in shaving a bit off the TRAILING edge of laydown brushes to improve efficiency and to eliminate the dead short which their escessive "wrap" creates. This has been true for every motor I've ever had until Big Jim introduced the "MVP" cut with BOTH the leading and trailing edges shaved down to produce about a 0.140" brush face width. When I got my first and only Orion CORE STOCK motor, I noticed the armature looked exactly like the MVP... This led to an "experiment" -- I tried sort of a 1/2 MVP cut, shaving only the LEADING edge of the brush... To my great surprise, it WORKED, and worked well! Just to prove to myself what was going on, I ran the motor on the track and then did some testing (see notes)...
NOTES:
1) This was an attempt to prove to myself that this motor (and so far it is the only motor for which this seems to be true) REALLY "likes" to have the LEADING edge of the brushes shaved down a bit rather than the usual trailing edge.
2) ALL tests were with the same brushes (this was a major pain, but I thought it was best for a "scientific" test). The change from leading edge cut to trailing edge cut and back was done by simply "flipping" the brushes in the brush hoods and then very diligently re-seating them.
3) The actual brush cut used is sort of 1/2 the "Big Jim" MVP cut, shaving one edge of the brush only, which brings the brush face width down from 0.185" to 0.163".
4) THIS MOTOR "LIKES" THE LEADING EDGE CUT! -- Note that the first test (fresh motor with full face serrated brushes) is pretty similar to the trailing edge cut test, and that the two leading edge cut tests are very similar, implying that the determining factor is the effective timing change introduced by cutting the 0.022" off the leading edge. I believe this has to do with the armature design (visually identical to the MVP), which becomes over-saturated with a full wrap, 24 degree timing, but is "happier" with the partial reduction in timing introduced by the leading edge cut and also with the reduced "wrap" of the now narrower brush face...
5) DON'T compare dyno's -- mine has always produced lower numbers than every other TD45 I've seen, but it's consistent, so it doesn't matter to me. On my dyno, the strongest motor ever tested was 98 watts at 20 amps at 7.00 volts, and I consider any motor with 90 watts or more to be a decent motor, with most of my race motors being in the 90-94 watt range...
6) All testing was at 7.00 volts, with the motor starting "cold", with each test consisting of 2-4 "pulls" until I got two back to back pulls that were essentially equal, with the last one in the series being the result "of record" for this test...

COR#1 -- TOP/Orion CORE RS "Dynotuned"
Brush: Stock 41200 (w/'1' in circle stamped on back)
Springs: (TOP/Orion)Red+/(TOP/Orion)Green-
7 Total Runs, with 3 Runs since Re-Build

Test: 20030111c -- Raw "Out of the Box" (uncut serrated brushes seated to the corners)
25507 2.7 51 49 @15A
23600 4.3 75 60 @18A
22423 5.3 88 63 @20A
21205 6.2 97 63 @22A PwrBand(15A-28A): 7,178 RPM
19742 7.5 110 63 @25A
18329 8.5 115 59 @28A

Test: 20030206b -- Raw After 3 Runs in XXX-KE, w/0.022 shaved off LEADING edge of brush
21979 4.1 67 64 @15A
20845 5.3 82 65 @18A
20025 6.1 90 65 @20A
19300 7.0 100 65 @22A PwrBand(15A-28A): 4,970 RPM
18184 8.1 109 62 @25A
17009 9.2 116 59 @28A

Test: 20030318d -- w/0.022 shaved off TRAILING edge of brush
27225 2.3 46 44 @15A
25111 3.7 69 55 @18A
23540 4.7 82 59 @20A <<<< Gear@
22244 5.6 92 60 @22A PwrBand(15A-28A): 8,456 RPM
20461 6.9 105 60 @25A
18769 8.2 114 58 @28A

Test: 20030322b -- w/0.022 shaved off LEADING edge of brush (As in 20030206b test)
22840 3.8 64 61 @15A
21593 5.1 82 65 @18A
20723 6.1 94 67 @20A <<<< Gear@
19969 6.9 102 66 @22A PwrBand(15A-28A): 5,189 RPM
18808 8.0 111 64 @25A
17651 9.1 119 61 @28A

Interesting,

We've tried the same thing in 12th scale. It seems like if you're running a motor that has less useable RPM (Either a high torque low RPM motor or a 4 cell motor with lower RPM) reducing the timing will generally produce more power.

Just as a note for everyone, the reason that we advance the timing in our motors is to compensate for the "rotation" of the magnetic field while the motor is running. A motor that runs at a lower RPM will need less timing to compensate. This seems to hold true for stock motors.

Interesting.... I didn't see this last bit of discussion till just today, I happed to be searching for some other info that I new was in this thread, and noticed that there were a few new posts i had not seen.


Up untill a month or two ago, I never cut any brushes except for a few cuts I made using the 'big jim' cut that trims both sides of the brush. Months ago now when Tfram started discussing brush overlap and shorting, is when I first got into it. Prior to that I really hadn't given it a whole lot of thought or consideration. Since then, I don't run any full faced brushes any more. When I first started playing with it, it was on a MVP. I first tried triming the leading edge, going with the my on guess that the MVP basicly had too much RPM and could stand to loose a little, and that triming the leading edge would be better. My first testing both on the track and the dyno was very promising, my MVP had never ran so good. (I've always hated them, but I only run 4 cell racing and I think that is part of the reason they didn't work so well for me). Later for kicks I tried reversing the brushes, to my surprize the results for me were very simmilar to when I had them in with leading edge trimed. I didn't really attempt to document any of this, I was just killing time one day at the track basicly.

For me, P2K motors have always ran good, and what I've come to beleive is that they don't seem to mind runing a full faced brush, and triming either edge of the brush doesn't seem to effect things very much at all. I've also observed that spring tension also doesn't seem to effect the proformance of P2K motors as much as it does on other motors. I'm not sure why this is.

I've played with quite a few Paradox motors as well, and they do seem to be more effected by triming brushes one way nor another, and also by spring tension, at least more so that I had observed with the P2K motors I played with. To be fair, I've probably spent more time on Paradox motors then any other motor, simply because I have a whole bunch and they just make a good motor to test with since the hoods are easy to tweak, and again I have a bunch of them.

Basicly I have never attempted to document what Tfram just reported on. I find it interesting, and ceritianly worthy of futher exploration.

Here is one of my current quandrys... I'm basicly really looking at moving on from stock racing and moving toward 19 turn racing. Mostly because I'm still a oval guy, and quite frankly 4 cell stock racing is kinda slow, and 19 turn is appealing simply from a speed factor. Now ROAR is apparently making 4 cell 19 turn oval a offical class. Basicly addopting the ARCOR motor as the standard if I understand it correctly. The reason I'm telling you this here is... I'm really looking forward to learning more about timing and how it effects motors and racing.

I expect I'll also still do some 4 cell stock racing, simply because I know that I have not even come close to mastering it, and would like to be able to do much better at it then I currently can. Stock motors are also still very fun to play with, and try to find ways to EEK out one more watt of power, etc... What I'm thinking now is that rather then playing with reversing the brush and such, why not just play with timing? Is there any real differance between changing the timing and triming the trailing or leading edge of a brush in a fixed timing motor? There may very well be a differance, but exacly what it is, is not very clear to me at this time.

In direct comment/question of what Fred and Tfram have just discussed... Other then trial and error, how would you know when a motor is likely to need more or less timing? (or when to trim the trailing or leading edge?) I mean Fred says timing is not needed as much on lower RPM motors, and is needed more on higher RPM motors... where is the line that determins when to switch...

Moments after I posted that last one... I got to thinking... What effect does voltage have on the perfect timing and/or brush overlap.

We know that RPM increases with voltage, so it's likely to have some effect on these issuses if for no other reason then the RPM is significantly effected by voltage.

Somewhat simmilarly... I continue to beleive that a Monster motor is a better 6 cell motor then it is a 4 cell motor. But I'm really unable to understand why.

HI Dyno...

About the question of when to trim, where to trim, etc...

What I have seen so far (again, based on a limited sample), is that motors with strong magnets (MVP, CORE for example) with the "MVP" armature (both the MVP and CORE use what is visually identical armatures) with the holes drilled in the laminations are ones that are "different". I blame this on the hole drilled in the center web of the lamination -- my theory is that it disrupts/weakens the electromagnetic field by eliminating the "iron mass" right at the center of the wire coil. The net effect is an "RPM" motor because the motor is now a poorer generator, thus reducing what is referred to as "back EMF". The negative side effect of this method of getting higher RPM's is that the lamination core can easily become over-saturated by the magnetic field generated by the windings. Once the laminations are saturated, all additional energy just produces HEAT and loss of efficiency. By reducing the "wrap" (and especially by trimming the leading edge and reducing the timing), it is possible to "tune" this so that you still saturate the armature without over-saturation. This optimizes power, efficiency, etc. and reduces heat. Since the MVP seems to have stronger magnets than the CORE, the MVP seems to "like" having both the leading and trailing edges trimmed while the CORE seems to "like" just trimming the leading edge...

Other motors, either due to weaker magnets or a non-drilled armature lamination (EPIC motors seem to "play" with the crown of the lamination, which affects the effective timing of the electromagnetic field but doesn't reduce the ability of the laminations to avoid over-saturation) seem to be MUCH more tolerant of a full face brush or a trimming of the trailing edge.
EXAMPLES:
1) I have a pair of C2 19 turns from Todd Putnam, and he barely shaves the trailing edge (brush face is 0.180"), but this is for an EPIC with a solid armature with no gaps...
2) P2K's have a altered lamination crown , but a nearly full stack (only about a 1/16" gap), so they can also tolerate a full face, but can benefit from a slight shaving of the trailing edge to gain efficiency by reducing the "short".
3) P2K2's have an altered lamination crown, but different (less alteration) from the P2K, but they also have a bigger gap (around 1/8") in the laminations, so they can saturate easier. I find they NEED some form of trimming the trailing edge (I use a 0.163" brush trimmed on the trailing edge). They seem to really be happy with this as they keep full timing, eliminate the short and seem to just reach full saturation without over saturation...
4) GM3's and Monsters have a greatly reduced armature stack, making them very sensitive to brush face size. I'm finding that they do NOT like the "MVP" cut, but that a trimming of the trailing edge (0.163" like the P2K2) combined with a thin dremel cut slot maintains optimum "wrap", eliminates the short, and reduces the brush face enough to flow just enough current to saturate the arm without over saturation..

"As always - Your mileage may vary"

OH -- I have an ARCORNITE that I have done some tuning/testing on if anyone is interested, but I have NOT gotten it on the track yet.

OK -- I'm still sort of new at adjustable timing motors (used to run "lizards", now testing an ARCOR motor)... Just "FYI", here are 5.00v TD45 dyno pulls for my one and only ARCORNITE with serrated 4383s, and springs equivalent to typical Red + / Green -:

MotorID: ARC19a

Test: 20030330c Desc.: 36 deg retest 19t
25166 1.8 34 32 15A
23313 3.1 54 42 18A
22185 4.1 67 48 20A
21186 4.9 77 50 22A
19789 6.1 89 51 25A
0 0.0 0 0 28A

Test: 20030327d Desc.: w/24 degrees 19t
19336 3.7 53 50 15A
18209 5.0 67 54 18A
17365 6.0 77 55 20A
16832 6.8 85 55 22A
16060 7.9 94 54 25A
0 0.0 0 0 28A

Notice that, within the test range of my TD45 (power supply limitations, etc.), the 24 degree test shows much better numbers, but when I look at gearing, I'd have to go to a HUGE pinion gear to get the needed rollout. By using the 36 degree setting, I can use a more reasonable pinion. I should note that some racers have had great success by going to a very small spur and big pinion so that they can use the 24 degree timing setup...

I'm kind of in the same boat with 19 turn motors. I've got a Chameleon 2 that I think runs quite well, but now ROAR using the adjustable timing in 19 turn, I figure that is the one to start working with to figure out how to make them run. Currently I can run any 19 turn I want basicly because our local racers basicly don't really care what kind of 19 turn you run.

I know my Chameleon requires a pretty big low ratio to use it's power... Others running ARCOR generaly have the timing cranked just about till the ring won't hold the endbell on. They seem to have less total power then a Chameleon, but they still seem to do quite well on the track. I don't fully understand why, and it has me really currious and wanting to understand more about timing and such.

It seems like this has basicly just given me a really good excuse to buy a ARCOR 19 turn and start playing.

Although I don't own a Fantom dyno, I was given the oportunity to put my ARCORNITE on one at an area track Saturday...

The pull was done at 36 degrees of timing, and they declared the motor "a keeper", so for that dyno, it looked good. Here are the numbers:

92.06 power @ 12623
23,800 peak @ 2.9 seconds
1.130 torque
65% Eff. at 16,713

For their track (flat carpet oval, around 135' racing line, 19t track record is 60 laps), the Fantom says to gear for 1.815" rollout... (Last time I ran a C2 on this track, before they went to the ARCOR motors, I geared at 1.837" rollout for a Putnam tuned C2 motor...)

Guys running TI based ARCOR's at 24 degrees are using a rollout of around 2.45"....!

Thats inline with what my Arcornite pulled on a Fantom, RPM's were the exact same, and my power was 94. So atleast we agree on what they get, and that was at 36 degrees of timing.

Thats inline with what my Arcornite pulled on a Fantom, RPM's were the exact same, and my power was 94. So atleast we agree on what they get, and that was at 36 degrees of timing.

I found it very interesting that the "spin up" time was so good too. I was worried that all that timing might drop the torque enough to make it take a while to spin up. But a 2.9 sec. spin up time looks pretty good to me. On short flat tracks, sometimes the spin up time can be a VERY important number. I know that with stock motors I've had some that looked decent on power and RPM, but had a 5 sec. spin up time and they just never performed -- when you turn a full lap in 4-5 seconds, a motor that takes 5 sec. to spin up never gets the job done...

Yeah, I hear you on spin up. :) Mine was 2.90 as well. :thumbsup:

Well... I've got me a Fantom Ti based ARCOR motor now... and I'm thinking about buying a Trinity Arcornite motor tomorrow... So I should be able to get some of my own data soon.

I know I raced some others with my Chameleon this past weekend. At least one other guy was using a Ti based ARCOR motor. By the end of the day We were all running very simmilar lap times, I had my Chameleon 2 geared at 2.74" rollout. I know one ARCOR Ti guy had a very simmilar rollout, but I'm not sure what he had his timing set at. One ohter that I think was using a ARCOR motor had a significantly lower rollout, and yet he too was running very simmilar lap times. This was on a rather large oval...

My Chameleon 2 is about a 88 watt motor on my Robitronic. I can't remember for sure what it was on the Fantom. 90 is about as good as I've ever seen on my Robi. If I remembr correctly, some locals have 19 turn motors that show well over 100 on a Fantom.

I spent about an hour last night dynoing my new Ti based 19 turn ARCOR motor. I'm starting to get a better picture of what happens when you increase the timing on these motors. At this point I don't have a detailed aynalisis of what I see, but I beleive this is one of those situations where viewing motor proformance in relation to amp input is really quite misleading.

What seems to hapen when you increase the timing of these motors (and it's probably simmilar to what happens with any mod motor) is that the shape of the power curve changes significantly in relation to RPM. Peak RPM increases with timing, yet the point of peak power in relation to RPM doesn't change quite as much. So... lets say at 24 degrees of timing peak power occurs at 45% of maximum RPM, but at 36 degrees it is more likely to uccur at 40% of maximum RPM. This may seem like a very trivial thing, but I don't think it is really.

What also happens is that peak power declines slightly, like 1 or 2%, but power near the peak RPM increases more like 30% or more. When you apply gearing (based on looking at data with Golden's DynoViewer), you see that say at 10,000 RPM the 24 degree motor puts out 123 watts and the 36 degree motor puts out 120 watts. Yet at 20,000 RPM the 24 degree motor puts out 52 watts and the 36 degree motor puts out closer to 69 watts. So, it could be said that when you increase the timing from 24 degrees to 36, you give up like 2% of your power in the corners, yet you gain like 30% more power at the end of the straights.

The question becomes this... which would you rather have? 2% more in the corner, or 30% at the end of the straights?

When I first started racing 19 turn, and started dynoing guys ARCOR motors who were really fast, I couldn't understand how they mangaged to be so fast, because at the time I was looking at data in relation to amp input, and peak power was clearly lower, as was power at every other amp step along the way. It just didn't make any sense to me. Well... if you look at it in relation to RPM and you apply some gearing, it becomes more clear.

Don't think you gain 30% at higher RPM for free... Amp input at those higher RPM is also higher then it is with the 24 degree timing, but it's still realtively low... At the same point where I told you the 36 degree motor had 30% more power then the 24 degree motor, the motor was also consuming 42% more current. The 24 degree motor was drawing just 13 amps, where the 36 degree motor was consuming 18.5 amps. Just be aware that at peak power these motors are consuming more or less equal amounts.

In short... there's more to what first meets the eye when you strart cranking the timing on a motor. I'm no expert on this, as I've just recently started looking into it... but I know for sure in many cases a motor with 36 degrees of timing will beat a 24 degree motor, even when it has slightly less peak power.

I'll try and document this as best I can soon. I will also say that higher RPM in a fixed timing situation like stock motors, doesn't ussualy look quite the same as what I see when higher RPM comes as a result of higher timing. RPM is not always created equaly.

I should also warn that apparently this situation I describe is pretty hard to see on a TurboDyno. I've entered Tfram's data into Golden's DynoViewer, and I see that it's virtualy impossible to see what I see when using my Robitronic data. with the CE TD data, it appears as if gearing alone will take care of the RPM differances. Part of the reason for this I beleive is because at 5 volts, the loction of peak power on one of these motors is higher then 40 amps. Tfram's data only shows a small portion of the total picture. I don't really mean this as an attack on TurboDynos... I'm just pointing out what I see, and if you try and see what I'm describing with Tfram's data, it's going to be impossible from what I can tell at this point.

Dyno,

You can place a trend line on the turbodyno data in excell. I forget exactly what I was using but it actually comes out pretty close to what the motor would put out on the dyno. You can use the equation of this trend line to extrapolate approximate performance at peak power. I used some 5 volt stock data to prove it out and it's surprisingly close.

Looks like I used a 2nd order polynomial for power and EF and just a straight line for torque and current.

It looks like TFram's data doesn't go up far enough to show the curve for power. I think we might need to go to at least 30 amps to get a reasonable curve. The power trend does follow what you are saying.

As I mentioned in one of my posts, my power supply doesn't let me go far enough into the power curve, so I agree with your observations... I'm using a heavy duty 30 amp supply, and for 6-cell offroad testing, where actual amp draw seems to average around 20-22 amps, I'm fine for stock class motor tuning. BUT -- for "Mod" or for 4-cell oval, it's different. In the last year or so, 4-cell oval around here has gone from using efficient, "torque" motors to amp-sucking RPM motors, and even for stock, average amp draw is more like 25-30 amps... I should be able to add a 28 amp step to my TD45 with my current power supply, but I know from experience that a 30 amp step is "out of bounds" (the dyno seems to complete the pull, but the LCD display goes blank during the 30 amp segment!)...

As you have noted, for modern stock motors and for "mod" motors, I'm clearly not getting the peak power point...

By changing the power source to a 12 battery, I should be able to go all the way to the dyno's 45 amp limit, but I've purposely avoided that up to now...

Since the Robi and Fantom use a battery type power source, they can map out a more complete power curve... Sigh... I still prefer my TD45, but....

I think what you have is fine for general tuning in mod. A small battery would do a good job but, it's kindof a pain.

I prefer the TD as well...I just need to send it in for the 45 amp upgrade.

If you have the DynoViewer and would like to see some of the data I collected last night, I've zipped up 4 text/data files that represent my Fantom 19 turn ARCOR motor set at 4 differnt timing settings. 24, 30, 32, and 36.

THe files are ziped in the following file

http://www.wiltse.net/zips/timing19.zip


At this point I'm thinking I might start out with a bit of a compromise and run like 30 degrees of timing.

If you look at those files with the dyno viewer, you will see that if you look at the data in relation to AMP input, the 24 degree timing appears to be better all the time. Yet if you swtich to the RPM based graphs, that's when things get interesting. What I see, is what I would call a 'wider' power band (wider RPM range) with the higher timing.

For those of you who don't have the DynoViewer, or simply don't want to download and look at the data... I have thrown together a very quick web page with 3 differnt images, and a very breif explination of what they are.

http://www.wiltse.net/timing19.html


I would really encurage you to look at the data more extensively with the DynoViewer, I simply can not begin to show you all the subtle differances that can be seen between the various timing settings and how it effects torque, current, RPM, power, etc...

Perhaps I can get my answer here. What RPM is max on a 4 cell stock motor with a light load. All I am trying to figure out is top speed of my carpte knife. I don't have a clue what the RPM is of my motor at the end of the straight. Its a P2K2. Rollout is in the real low 40s.

I asked in a different forum and aparently there I am stupid.

Thanks all you dyno guys, I am learning a lot about power from all this stuff with out owning a dyno or spending the time you guys do.

And YES mister MO Hum, it seems to me a little more tension on the brush springs bring on a little more torque. So thank you.

David Root

Perhaps I can get my answer here. What RPM is max on a 4 cell stock motor with a light load. All I am trying to figure out is top speed of my carpte knife. I don't have a clue what the RPM is of my motor at the end of the straight. Its a P2K2. Rollout is in the real low 40s.

Well -- The only stupid question is one you don't ask because you don't know you don't know... LOL! You are welcome here... We all started at the beginning too...

Based on what I see with 4-cell stock 12th scale onroad (I also have a 'Knife 3.1) and in 4-cell stock oval, here's my guess...

Even with small rollouts to let the motor "breath", and even with a long straight, the friction and aero drag will probably never let the motor get past around 17,000-18,000 RPM for a P2K2... That is a typical range for my good P2K2's at a 15 Amp load on my TD45 dyno... These motors almost pull that much amperage with NO "load" so I figure that's a real world max RPM range... I'd say use 17,000 as a "typical" value...

Does that help?

Thank You! It was my guess too. I figured some where between 17 and 22, closer to the 17 because it is 4 cell.

I have learned much on that other message board, but seem to have out grown it. I am as fast or faster than most on the straight when I am racing stock. Now i am working on my driving skills. That is why I jumped into the 12th scale. I love it. Simple and straightforward Yet the most difficult to master for me so far.

Off Road starts here in a month or two, I can't wait to use what I have picked up over the winter in knowlege and driving skill.

Thank You
David Root :wave:

Now i am working on my driving skills. That is why I jumped into the 12th scale. I love it. Simple and straightforward Yet the most difficult to master for me so far.

Off Road starts here in a month or two, I can't wait to use what I have picked up over the winter in knowlege and driving skill.

I've always found that 12th scale hones driving skills more than any other form of racing -- it's all about smoooooth, "the line", carrying momentum in the turns, etc... I've found that stock offroad on a tight, technical track is a close second for many of the same reasons.

My first love is Oval (mostly 4-cell stock now), but I don't get to do as much of that lately....

Slightly off topic but does anyone have any Robi dyno data for modified motors particularly the Orion Core Touring 12x1, or indeed for a P2K2.

I've got lots of Robitronic data, not for 12 turn Orion modified motors, but alot for stock motors, and some for 19 turn motors. I for sure have some P2K2 data somewhere...


What exactly are you looking for in the data?

I may have some 12 turn arms somewhere and could possibly throw one in a can and make a couple runs. However I'm just recently getting into modified motors, and I can tell you at this point the results are highly dependent on the timing and that interpetation of just exactly what is good and what is bad is not really known by me at this time.

Go back to my last few posts about my 19 turn ARCOR motor and you will get some idea of why I consider modified motors to be whole new chapter in my own personal quest to understand motors and dyno numbers.


I will add that my latest experiance in 19 turn racing was a very positive one. I'm very much looking forward to playing with timing and 19 turn modified motors. My first race experiance with adjustable timing motors was very good.

Dyno: What is the latest version of Mike's Dyno viewer? I have 1.3.5 Would like to be able to print my TD 45 data. Just now getting into oval. My calculations showed a rollout, but motor was flat. Put the data into DV and rollout dropped 1.6 teeth! Showed me what I missed.

In relation to the P2K2 it was just for comparison on my motors which are standard. I wanted to see when I start fiddling with them that I am moving in the 'right' direction, or is it just a question of max power and then gear it to suit?
As for the modifieds again it is the same as above, but what would be good power figures for a 12x1, std timing. I only got the motor and didn't get to dyno it before using it and was wanting to gauge if it had gone off much (187 Watts at present, seems low?).

300M, the newest version of Golden's DynoViewer is 1.3.5. I'm not sure what you mean when you say you put the data into the DV and the rollout droped... The DynoViewer really only helps to gear a motor in relation to another motor. If you line up the torque and power of two motors, then you can refferance the gearing for the second motor if you do it right it works pretty good. When/if you start talking about mod motors, then it can get kind of interesting in trying to do this gearing if you start playing with timing.

Mattlyness, for fixed timing motors like a stock motor I recomend tuning for peak power. A good stock motor at 5 volts is about 62 watts peak, with the highest I've ever seen being about 64 watts. At 7.5 volts the start of a good motor is about 128 watts peak, and I've seen a few up towards 134 watts peak.

As for the 12 turn... I can't comment much on that at this time. I will see if I can find a 12 turn arm to play with, but my recent experiance with 19 turn adjustable timing motors is that it can get very tricky trying to decide what makes the best motor once you start chaning the timing. The best I can do at this time with regard to mod motors is refer you to my recent posts where I played with the timing on my 19 turn motor. When I ran that motor this past Friday I ran it at about 28 degrees, and then once cranked it up to about 30. It ran better at 30 then it did at 28... On the dyno, it's very hard to see exactly why. The reason why seems to be in the basic shape of the torque curve.

If you don't have Golden's DynoViewer yet, I recomend getting it....

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

I'm not 100% sure if that is the latest DynoViewer or not, install it and then check to see if it's version 1.3.5, if it's not then down load this other file and use the .exe in it insted of the .exe the instaler put in place. (you won't need to re-install however, just use the newer .exe)


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

PS... if you download the DynoViewer soon, and find out for sure if the main zip file has the newest version or not, please let me/us know... I can't remember for sure it's been so long since I did it myself.

300M, the newest version of Golden's DynoViewer is 1.3.5. I'm not sure what you mean when you say you put the data into the DV and the rollout droped... The DynoViewer really only helps to gear a motor in relation to another motor. If you line up the torque and power of two motors, then you can refferance the gearing for the second motor if you do it right it works pretty good. When/if you start talking about mod motors, then it can get kind of interesting in trying to do this gearing if you start playing with timing.


Thanks Dyno. I still green on the oval so I am still in the seek and find on general rollout. I do a comp of 20 amp number to ge the rollout. What the DV showed me is something I forgot about one of my P2K2's. That one likes less gear, like a monster does. If I max the numbers out without looking at the curve the info is not evident. Looking at the curve the power/RPM dip from high to low in the 20 amp range. So I geared wrong. Could tell in the final as power was off.

In 4 cell stock racing with a pan car, typicaly we have been running between about 2.3" and 2.6" rollout. I beleive I was told that the track had about a 190' run line. Last time I ran stock my fastest lap times were with about a 2.32" rollout with one of my Monster Motors. I beleive I'd be pushing 2.5" with a P2K2, I might push 2.65" with a P2K if I were to run one. However I also know some very fast guys that can run close to 2.5" with a Monster, to some degree it depends on your ablity to keep the speed up in the corners and/or your driving ablity. I don't think I'd go much lower then this, unless the track was really short and wouldn't hesitate to go higher if the track was longer.

I find this interesting, I gear my 1/12 on road for a rollout of 1.62 or 41mm. Nothing to do with Dyno Data, but I would never go near 2.5" or 63mm. All I would do is go slow or smoke my motor. This is stock P2K2.
I go as fast as everyone else on the straight. The guy that held the track record was geared about the same. I have NO idea what the oval guys use for rollout. the track is 40 X 80 or 40 X 100.

Like David, I was using 42mm rollout on my 1/12. 23x53 track On the oval higher, from memory, the oval numbers are considerbaly higher. Not 100% but like Dyno 2+ David, the 1/12 weight is 28 oz. 1/10 Oval weight is 39.8 That will drive up the rollout. I use the same motors in 1/12 and 1/10 P2K2 or P2K. Monster I have I am not impressed with.

Are you running Roadcourse in 12th? That's just a little lower than what we were running the ROM at on the roadcourse but pretty close.

If not already clear, the rollout numbers I gave are for 4 cell stock oval racing. I don't beleive I've ever ran any less then 2.0" rollout this year even on the shortest track. It seems that the rollout that is typical for many of those I race with has gotten higher over this year's racing. If I remember correctly in the begining of the year we were running around 2.2", and lately as I say, even with the Monster motor and it's big RPM we have been running higher then that.

We average about 30 amps, maybe even slightly higher, or I supose slightly lower depending on lots of factors. Near as I can tell we are operating at very close to peak power for about 90% of the race. The cars really don't accelerate that much from the end of the corner to the end of the straight, mostly because the fast guys get through the corners at a very high rate of speed.

We are running a flat carpet oval that I am told has more or less the same dimensions as the track that was used at the snowbirds this year. I think the track record was like 52 laps in 4 cell stock. My personal best was just 49 laps. The fastest guys are capable of doing 4.5 second laps in the opening laps, and typicaly slow to like 4.7 seconds near the end of a race. My own personal best lap was like 4.7 seconds, typicaly I go about 4.9 or 5.0, my goal has always been to achive some consistant 4.8 second laps and really never quite achived that goal this year. I've spoken with all the fastest guys and my rollout is very close to what others are running, as are my average amp draws. Bascily my problem is driving and car setup. I still don't feel all that bad about my own situation because many of my competitors are really more or less capable of speeds that would do quite well in national events, also because this is my first year of really competitive oval 4 cell pan car racing.

Fred: Yes, road course with the 1/12. Oval with the 1/10 (KSG).
rollout for the MVP is lower. I do not use the moster as it is a RPM freak and I am not partial to those. Prefer the P2K2 as a good all around motor.

Reading my last post I was not clear. For Oval I run 2.0+ rollout. Depends on the motor.

Dyno, we have a big shootout at our track next weekend so I am not going to give my actual rollout number. Have to have some advantage of my labor and they did not give theirs when we were at their track. :D I understand the increase in rollout. In TC we were raising the bar more with higher numbers and more speed. Motors were really getting hot.

I just looked back through my dyno data. Rollouts for my T1 were ~28mm (1.12"). 1/12 was ~42mm (1.68") My KSG, 4 cell stock, the number are over 2.0. I have not checked the discharge nunbers as I have 2 new 3300's I have not cycled. Humm add that to the to do list.

Our track is 132' race line with 7 degree banking in the straight and 14 degree in the turns. Track record was set last week in masters stock. 67 laps 4:02 min In my 2nd week of racing I went from 51 laps to 55 laps :) I improved, and had fun. Record laps are 3.5 sec, my best to date is 3.9 My bud did a few pratice laps with the car and did 3.7 sec laps. So I am close on motor, car was tight. The guys are giving me hints on stettings and I am trying to get smooth running the line. I enjoy the racing and that is all that matters.

300M,

That probably is pretty close for an MVP in 12th. I too dislike the ROM for 4cell roadcourse. It always feels undergeared on the straight and overgeared on the infield.

FWIW, my all time favorite motor for 12th onroad is the GM3. We're running 767's and narrowing up the brushes until we stop dumping. Usually about 7 amps at 3 volts.

Fred: I use the MVP to pratice with and P2Pk to run. MVP is a dog, low on power. Was a freebie and not worth the time to make run. Using 768 in that as it likes them better or the narrow 766. I use the 769's in the GM3's they seem to like that brush.

Just thought I'd bump this up to the front.