Ok, what I'm I doing wrong? Just got a BK Precision Model 875B LCR Meter today. I went to the novak site and followed the instructions. My motors read lower than the site, by a good bit.. I zeroed the meter by the instructions that came with the meter.

13.5 BL:

#2 motor

no rotor- 59.6
rotor- 36.9 to 41.5


#4 motor

no rotor- 57.6
rotor- 36.4 to 40.5

#5 motor

No rotor- 59.7
rotor- 38.8 to 42.3 Lowest to highest reading

#6 motor

no rotor- 59.6
rotor- 38.0 to 41.1 Lowest to highest reading

I know the #6 motor runs good, its my best running motor!

I have dynoed and ran both motors and the #6 motor is much better than the #5 motor.


The motors are stock never tampered with...........

What is legal?


10.5 BL:

no rotor- 35.1
rotor- 23.1 to 25.6

Post your results!

Jflack,

We currently tech all motors at our track using an inductance meter and the numbers you are showing are very similiar to what i see every week. he one thing I've noticed is the hotter the motor gets the lower the number will be. BUT, if all motors are teched are the same time all should be close to the same. I dont feel as thow this is a good way to determine the performance of your motor but more to determine the range of inductance to be sure racers are within rules. I have noticed the faster motors due have a lower inductance. here is what I've found for numbers.
10.5- w/rotor mid teens--low 20's
13.5- w/rotor mid 30's--mid 40's
17.5- w/rotor high 40's mid 50's

Where did Novak post the motor information from the Snowbirds A-Mains?

Jflack,

We currently tech all motors at our track using an inductance meter and the numbers you are showing are very similiar to what i see every week. he one thing I've noticed is the hotter the motor gets the lower the number will be. BUT, if all motors are teched are the same time all should be close to the same. I dont feel as thow this is a good way to determine the performance of your motor but more to determine the range of inductance to be sure racers are within rules. I have noticed the faster motors due have a lower inductance. here is what I've found for numbers.
10.5- w/rotor mid teens--low 20's
13.5- w/rotor mid 30's--mid 40's
17.5- w/rotor high 40's mid 50's

So if my motor comes off the track at 140 motor B 170 motor C 120 and motor D 190 how can teching them be accurate? Wouldn't teching them at room tempature produce more accurate results? I wonder if a pre race tech is a safer way to do this? So many questions in BL yet all of a sudden nobody remembers how to take a motor out of there car! Funny how things work out...We used to cut comms every round, yet I havent seen one rotor out of a motor yet to check the sensor board location...This is not a slam to you....You are the only one I have seen atleast try to tech....

...since going Brushless - I don't know anybody other than myself that's taking motors out of their cars.

I do because I only have 4 motors and 6 cars, so I'm always having to shuffle from one to the other.

We also picked up an inductance meter this past week, and I'm going to test my motors - and a few others to get a benchmark and learn about what I'm looking at.

last year of the focar season everyone who ran 10.5 gave me there motors before they practiced! i took an hour pulling every rotor out of every can and checking the inductance with a meter. i than wrote down every reading and tagged each motor as legal for that days racing.

10.5 room temp no rotor 13.5 at room temp with rotor 34.2 35.2 34.9
31.2
30.6
30.0
31.2
31.6
31.8

a drop of epoxy paint on the purple ring and can works great for a days racing if the paint is split the motor needs to be teched again. i haven't seen anyone else in florida on-road or oval come close to this process......i think it's important,but i'm crazy!

last year of the focar season everyone who ran 10.5 gave me there motors before they practiced! i took an hour pulling every rotor out of every can and checking the inductance with a meter. i than wrote down every reading and tagged each motor as legal for that days racing.

10.5 room temp no rotor 13.5 at room temp with rotor 34.2 35.2 34.9
31.2
30.6
30.0
31.2
31.6
31.8

a drop of epoxy paint on the purple ring and can works great for a days racing if the paint is split the motor needs to be teched again. i haven't seen anyone else in florida on-road or oval come close to this process......i think it's important,but i'm crazy!
Not crazy at all...Every form of racing does this type of tech..It's called Pre-Race inspection..When I ran Super Latemodels we had a race at OPS Speedway once a year that gets 100 cars.Every car had to go through tech before they were allowed to practice.What your doing isn't un heard of at all...It also wouldnt be to much for the racer to have there motor out , apart and ready for inspection...It takes 2 minutes to inspect, assemble and seal. We don't seem to want to be bothered in RC..We are more interested in taking racers money and getting out of the door once the money is collected.... Sad..

P.S. Since when does a Race Director have no balls! Seems like they don't want to hurt anyones feelings..This isn't Politics this is RACING...If someone is doing something wrong then correct it....When I spend alot of money to go to a race my feelings are hurt when you don't tech!

the readings on the noval site are high..talked to charlie and he said that he was goning to update it soon..also the lowest 10.5 at the birds checked 31.4 from what i heard..

last year of the focar season everyone who ran 10.5 gave me there motors before they practiced! i took an hour pulling every rotor out of every can and checking the inductance with a meter. i than wrote down every reading and tagged each motor as legal for that days racing.

10.5 room temp no rotor 13.5 at room temp with rotor 34.2 35.2 34.9
31.2
30.6
30.0
31.2
31.6
31.8

a drop of epoxy paint on the purple ring and can works great for a days racing if the paint is split the motor needs to be teched again. i haven't seen anyone else in florida on-road or oval come close to this process......i think it's important,but i'm crazy!


Are those numbers with a BK precision meter? Makes a big difference when comparing!

I don't know how it compares to the other meters being used, but this is the meter we've got.

http://www.sedmm.com/UploadFiles/2007911516752.jpg

LC Meter Link (http://www.sedmm.com/product.asp?productid=103)

sorry my reading were not done with a bk meter...i have since sold the meter to another promoter here in floirda who will use it. it's in good hands now.

one of the reasons to get as many readings with "your" meter as you can with different motors....you will get a nice baseline to go by.

the guys in the 10.5 class were all more thsan happy to have there motors teched...we have a good group of guys...

JBR- Been telling you for weeks now about post race tech being inaccurate....YOU HEAR ME NOW!!!

Not crazy at all...Every form of racing does this type of tech..It's called Pre-Race inspection..When I ran Super Latemodels we had a race at OPS Speedway once a year that gets 100 cars.Every car had to go through tech before they were allowed to practice.What your doing isn't un heard of at all...It also wouldnt be to much for the racer to have there motor out , apart and ready for inspection...It takes 2 minutes to inspect, assemble and seal. We don't seem to want to be bothered in RC..We are more interested in taking racers money and getting out of the door once the money is collected.... Sad..

P.S. Since when does a Race Director have no balls! Seems like they don't want to hurt anyones feelings..This isn't Politics this is RACING...If someone is doing something wrong then correct it....When I spend alot of money to go to a race my feelings are hurt when you don't tech!

I've been saying that for while now! seems none wants to listen until things get out of hand..but i have had some converstations with certain people about pre race tech and sealing the motor!look for it real soon!

I did some research and this is what I have found for rules. I have not seen anything for 21.5 numbers as of yet.

BK875B LCR Meter


10.5 (Snowbirds A-Main tech)
31.40 Micro Henries minimum
36.00 Micro Henries average (Rotor removed)
???? Micro Henries maximum


13.5 (ROAR Rotor removed)
57.00 Micro Henries minimum
63.00 Micro Henries average
67.00 Micro Henries maximum

17.5 (ROAR Rotor removed)
102.00 Micro Henries minimum
105.00 Micro Henries average
108.00 Micro Henries maximum


[B][I][COLOR=#ff0000]21.5 ([FONT=Arial] Rotor removed)
[SIZE=2]???? Micro Henries minimum
136.00 Micro Henries average
???? Micro Henries maximum

Jflack- i see how you check its values but how did you dyno your motors?
they need a chassie dyno to check H.P.,Tq,mph and that would leave the motor inside the car
hook up a meter to the batt and set the car on the rollers and hit the gas and wala!
most classes run the same speedand have about the same acceleration find out a range and only tech the fastest guy's motor check inbetween each heat

Fantom Dyno....... The differences in the meter reading can be seen on the Dyno....

Fantom Dyno....... The differences in the meter reading can be seen on the Dyno....

I use the radio gear but on a Turbo Dyno. When our inductance meter shows I should see the same thing. A lower inductance reading with higher dyno numbers.

21.5 BL motor

rotor- 85.6
no rotor- 136.8

I use the radio gear but on a Turbo Dyno. When our inductance meter shows I should see the same thing. A lower inductance reading with higher dyno numbers.

Yes, I see higher reading in almost all areas.

21.5 BL motor

rotor- 85.6
no rotor- 136.8

Hey Flack, please post all 3 poles:

"AB"
"AC"
"BC"

I did some research and this is what I have found for rules. I have not seen anything for 21.5 numbers as of yet.

BK875B LCR Meter


10.5 (Snowbirds A-Main tech)
31.40 Micro Henries minimum
36.00 Micro Henries average (Rotor removed)
???? Micro Henries maximum


13.5 (ROAR Rotor removed)
57.00 Micro Henries minimum
63.00 Micro Henries average
67.00 Micro Henries maximum

17.5 (ROAR Rotor removed)
102.00 Micro Henries minimum
105.00 Micro Henries average
108.00 Micro Henries maximum


Here's a thought/question.....On the readings on Novak's site, the difference between a 10.5 and an 8.5 is only about 11.5 points inductance. The lowest motor in the 10.5 scenario is 4.6 points lower than the AVERAGE(not the highest number). That's more like a 9.7turn compared to an average 10.5! I remember when John Zubak had his now infamous mistake of running a 8.5(5800) motor when he thought it was a 10.5(4300), it was almost 3 laps difference when he changed motors. Based on that, I don't think it's unreasonable to think that the variance in the 10.5 motors may acutally be close to a lap difference......

Now, in all fairness, I don't know if Tony is claiming his info to be 100% guaranteed acturate or not, and if Novak updates their info for inductance it may change that scenario as well. But it is something to think about, and I think that's why some people are curious.....

Here's a thought/question.....On the readings on Novak's site, the difference between a 10.5 and an 8.5 is only about 11.5 points inductance. The lowest motor in the 10.5 scenario is 4.6 points lower than the AVERAGE(not the highest number). That's more like a 9.7turn compared to an average 10.5! I remember when John Zubak had his now infamous mistake of running a 8.5(5800) motor when he thought it was a 10.5(4300), it was almost 3 laps difference when he changed motors. Based on that, I don't think it's unreasonable to think that the variance in the 10.5 motors may acutally be close to a lap difference......

Now, in all fairness, I don't know if Tony is claiming his info to be 100% guaranteed acturate or not, and if Novak updates their info for inductance it may change that scenario as well. But it is something to think about, and I think that's why some people are curious.....

ROAR does not have rules for a 10.5 and a 21.5 so that info is up in the air.

Those are ROAR min/max (13.5 and 17.5) and what NOVAK has for average on the website. Nothing about "claiming", read section 8 of the ROAR 2008 rule book.

Those are ROAR min/max and what NOVAK has for average on the website. Nothing about "claiming", section 8 of the ROAR 2008 rule book.

Gotcha! Just wasn't sure if your info was printed somewhere or "this is what I've been told"! LOL That actually makes more sense too, because I think Jody M referenced the fact novak was going to update their numbers, so that might be why the difference is so big on the 10.5. I initially assumed the 10.5 average was the average of the 10.5 A main cars.....

Gotcha! Just wasn't sure if your info was printed somewhere or "this is what I've been told"! LOL

Now ROAR does not have rules for the 21.5 or 10.5 but just some info I gathered that tech used at the Birds (10.5).

8.8.4.3 Winding:

Modified Brushless Motors: Only three slot (phase) “Y” wound stators are

permitted. No delta wound stators allowed. Only circular (round) pure copper wire

permitted. No turn limit.

Stock Motor: Only three slot “Y” wound stators are permitted. No delta wound or

slot less stators are allowed. Only circular (round) pure copper magnet wire

permitted. The three slotted stator must be wound with 17.5 turns of 2 strands of

20 AWG or 2 strands of 0.80 mm IEC per slot. The inductance for each slot of the

stator shall be 102.00 Micro Henries minimum and 108.00 Micro Henries

maximum, measured with the rotor removed from the motor.

Super Stock Motor: Only three slot “Y” wound stators are permitted. No delta

wound or slot less stators are allowed. Only circular (round) pure copper magnet

wire permitted. The three slotted stator must be wound with 13.5 turns of 2

strands of 21 AWG or 2 strands of 0.71mm IEC and two strands of 23 AWG or 2

strands of 0.56mm IEC per slot. The inductance for each slot of the stator shall be

57.00 Micro Henries minimum and 67.00 Micro Henries maximum, measured with

the rotor removed from the motor.

ROAR does not have rules for a 10.5 and a 21.5 so that info is up in the air.

Those are ROAR min/max (13.5 and 17.5) and what NOVAK has for average on the website. Nothing about "claiming", read section 8 of the ROAR 2008 rule book.

Be a whole bunch of folks getting tossed out in the 13.5 class if those standards stay in place for Roar cause I have seen many motors lower than 57.00.

Matter of fact I have never seen one over 60 but then again I have only seen maybe 30 or so checked so who knows!

Be a whole bunch of folks getting tossed out in the 13.5 class if those standards stay in place for Roar cause I have seen many motors lower than 57.00.

:woohoo::woohoo::woohoo::woohoo::woohoo:

Does that mean you'll win? :freak::rolleyes::confused:

:woohoo::woohoo::woohoo::woohoo::woohoo:

Does that mean you'l win! lol

Prob not cause I only have 1 out 4 that reads higher than 57.:woohoo:

:woohoo::woohoo::woohoo::woohoo::woohoo:

Does that mean you'll win? :freak::rolleyes::confused:


If you build my diff I might! lmao

Matter of fact I have never seen one over 60 but then again I have only seen maybe 30 or so checked so who knows!

Maybe ROAR needs to update there current 2008 rule book and include the "Because Brian hasn't seen it rule"? lol

Just pickin' bud...........

If you build my diff I might! lmao

A SMOOOOOTH diff is a FAAAAST diff! Come by and see me my son and I'll hook ya up with the killer diff again!

Maybe ROAR needs to update there current 2008 rule book and include the "Because Brian hasn't seen it rule"? lol

Just pickin' bud...........


Nah they just need to get their head out of the sand and get some good numbers.

Jody tell your boy to build me a diff and quit worrying about motors! lol:freak:

stock racing keeps looking better! just cant win..lol another stupid rule

stock racing keeps looking better!

Damn cherry picker :eek:

stock racing keeps looking better! just cant win..lol another stupid rule

Speaking of stupid rules make sure you don't use motor freeze at a BRL race! lmao

Nah they just need to get their head out of the sand and get some good numbers.

Jody tell your boy to build me a diff and quit worrying about motors! lol:freak:

Oh no, got a box of 17.5's and 13.5's comin' in. They all need "F" brushless brushes, stealth springs, and the rotors turned.:dude:

I thought I was the only one turning my rotors...lol

so what kind of number should i be looking for on a 17.5 W/ the rotor?

Never seen a 17.5 BL motor, I think they are a Myth!

...I've only tested one 17.5 so far - w/ the rotor, and I'm in the 62.3 range. I have 2 more to test - but I need to unsolder them from the car.

like to see where that is compared to others.

62.5 to 68 is what I have seen on the 17.5. We have been inductance testing every week.

Thanks Bill,

We just got our meter, and I'm working on compiling a number base for the 17.5 and 21.5 motors.

charlie at novak said the only true way to test a motor is without the rotor! just to let you know if your gonna set some rules.

Not crazy at all...Every form of racing does this type of tech..It's called Pre-Race inspection..When I ran Super Latemodels we had a race at OPS Speedway once a year that gets 100 cars.Every car had to go through tech before they were allowed to practice.What your doing isn't un heard of at all...It also wouldnt be to much for the racer to have there motor out , apart and ready for inspection...It takes 2 minutes to inspect, assemble and seal. We don't seem to want to be bothered in RC..We are more interested in taking racers money and getting out of the door once the money is collected.... Sad..

P.S. Since when does a Race Director have no balls! Seems like they don't want to hurt anyones feelings..This isn't Politics this is RACING...If someone is doing something wrong then correct it....When I spend alot of money to go to a race my feelings are hurt when you don't tech!

Right On Justin! Thorough and accurate tech is long overdue for R/C. I have requested that my motors were torn down after I win a big race or National event..yes, requested it! That eliminates all gray area in anyones head, as well as removes any doubt there may be whether or not everything was fair and square.

From a manufacturer standpoint, it also positively promotes my business- another legal win in the books for Putnam. With all the nonsense that has taken place in the past few years, I make sure I'm not grouped in with the cheaters... :thumbsup:

And from what i have seen doing the inductance test , is with out the rotor installed the numbers stay the same each time you test, withe the rotor installed the numbers change with the location of the rotor, As you turn the rotor the numbers go up and down.

anyone dyno a 17.5 yet ? I messed with the one that just I just got but was shocked to see how low the numbers were. On the fantom with the esc set to 0 timing i got 36 watts 10700 rpm and 920 tq wit the timing up to 6 i got 42 watts 11700 rpm and 970 tq. I dont know how it compares to a 27 turn brushed as mine are running 67 watts just wondering if the motor is a dud the rotor gausses good on my gauss meter ? How are the other dynoed 17.5s compare to your 27 turn brushed motors

from what I've heard the FANTOM type dyno won't get you good numbers w/ that low of rpm motor. They look much better on a turbo dyno.

We know by the way they pull, a 17.5 has more power than a brushed stock motor.

ok when I get home today I'll spin it up on the turbo dyno to test it i also have the robitronics and a quillen dyno just to see what the results are. I know my mamba drag motors make over 700 wats on the fantom with the regulator off and a 4 cell lipo . The 17.5 has low low rpm only 11700 so mayne your right but i dont see crazy tq numbers either albie