29LikesBest 17.5 Motor For 2017 TC?
06-05-2019, 09:38 AM
#46
I run on asphalt,
okay, maybe I'll go w the R1 then. It is what most at my club are running.
As for motor analyzers, I have one and have done my own tests as well. Funny thing I've noticed, some motors put out more RPM on the analyzer yet on the track are slower. Iam guessing other variables play a factor in real world racing vs what the analyzer shows.
okay, maybe I'll go w the R1 then. It is what most at my club are running.
As for motor analyzers, I have one and have done my own tests as well. Funny thing I've noticed, some motors put out more RPM on the analyzer yet on the track are slower. Iam guessing other variables play a factor in real world racing vs what the analyzer shows.
06-05-2019, 09:40 AM
#47
I run on asphalt,
okay, maybe I'll go w the R1 then. It is what most at my club are running.
As for motor analyzers, I have one and have done my own tests as well. Funny thing I've noticed, some motors put out more RPM on the analyzer yet on the track are slower. Iam guessing other variables play a factor in real world racing vs what the analyzer shows.
okay, maybe I'll go w the R1 then. It is what most at my club are running.
As for motor analyzers, I have one and have done my own tests as well. Funny thing I've noticed, some motors put out more RPM on the analyzer yet on the track are slower. Iam guessing other variables play a factor in real world racing vs what the analyzer shows.
06-05-2019, 08:48 PM
#48
Tech Master
Ive been trying to help people who use motolyzer figure out how to tune a motor that is loaded and their isnt a perfect quick and easy way. Your hunting for 2 points. Peak efficiency (cooling) for timing and peak power for lap times. But the points move dramatically from loaded to unloaded.
peak efficiency (timing and minimal heat) is 10-15 percent less rpm than peak power. Finding the peak of power should be done with gearing first regardless of heat. If you find the best lap time with gearing first and then adjust your timing to the coolest motor you will find peak efficiency. Now you have the two peaks. If you then go back to changing the gearing to move motor rpms up by less than 10 or 15% and dont overheat the motor in a race you can make tiny adjustments to timing to pull a little more temp out. Between 40-50 degrees usually.
im not convinced that is simple enough and still concise but maybe..
peak efficiency (timing and minimal heat) is 10-15 percent less rpm than peak power. Finding the peak of power should be done with gearing first regardless of heat. If you find the best lap time with gearing first and then adjust your timing to the coolest motor you will find peak efficiency. Now you have the two peaks. If you then go back to changing the gearing to move motor rpms up by less than 10 or 15% and dont overheat the motor in a race you can make tiny adjustments to timing to pull a little more temp out. Between 40-50 degrees usually.
im not convinced that is simple enough and still concise but maybe..
06-05-2019, 09:57 PM
#49
Just get a Fantom icon or v3t/v3R tour gear it and call it a day.....Lots of headaches(smoking) with the other brands.....Good Luck at the Roar Nats !!!
06-06-2019, 06:42 AM
#50
get any of the recent top-of-the-line motors and you'll be 99% there, be it BrandA or BrandZ.
Until you can drive a full 5 minutes in the A-main with 0.3s consistency, any amount of that hypothetical extra 1% you *might* get with the new "motor-of-the-month" is useless except for lightening your wallet... and even then...
Until you can drive a full 5 minutes in the A-main with 0.3s consistency, any amount of that hypothetical extra 1% you *might* get with the new "motor-of-the-month" is useless except for lightening your wallet... and even then...
06-06-2019, 06:44 AM
#51
06-06-2019, 09:02 AM
#52
I agree with Lonestar's post. Most of the motors are very even today. Driving and Setup are more important factors. I have Team Powers motors, R1, and Trinity. I really like the Team Powers and R1's. Pick your poison..... I do feel that there is a difference in performance should you have a 2 year old motor for stock/blinky classes....
06-06-2019, 09:41 AM
#53
Tech Initiate
Kv. absolute timing and unloaded current (amps) tell you nothing about how much power the motor makes. The only effect of kv is that you have to adjust your gear ratio to compensate for a difference in kv between different motors. Unless you are limited by the gear ratios you can run due to rules or physical configuration of the chassis you shouldn't care for what the kv of a motor is.
A 3000kv, 150watts motor will be faster than another motor which is 4000kv, 120watts once the gear ratio has been adjusted to suit. The only way to know how much power a motor is capable of is to 'sweep' the timing in fine increments (1degrees) and dyno at each timing. You then pick the timing which produces the maximum power, and don't care for what the resulting current, torque or Kv is.
If you don't have a motor dyno and use lap times to tune then you inevitably end up playing a balancing act between motor timing and gear ratio. Adjusting the motor timing will change the Kv which can compensate for an inappropriate gear ratio. So if you are just adjusting motor timing and measuring lap times you may arrive at a motor timing that gets you the fastest time for your current gear ratio, however the timing will not be optimal for the motor to produce maximum power. With the motor timing adjusted for maximum power and the gear ratio adjusted for the resulting motor kv you will go even faster.
The only significance of the unloaded current measurement is that it is a rule-of-thumb to gauge if the motor is going to run blazing hot (if it measures like 20A+) and perhaps run down the battery too much over the course of a long race. If you only care for making power, you shouldn't care how much current it draws unloaded. However, if your battery runs down and decreases in voltage over the course of a race then motor power goes down too. Starting the race with slightly lower timing and therefore lower motor power but having the motor run much more efficiently (e.g. 6A unloaded current draw instead of 20A) may mean that the motor power doesn't fall off so much towards the end of the race. Then there is the possibility of using a higher capacity battery so the battery voltage doesn't drop as much over the race, keep the motor timing optimised for max power but have the weight penalty of the higher capacity battery...
A 3000kv, 150watts motor will be faster than another motor which is 4000kv, 120watts once the gear ratio has been adjusted to suit. The only way to know how much power a motor is capable of is to 'sweep' the timing in fine increments (1degrees) and dyno at each timing. You then pick the timing which produces the maximum power, and don't care for what the resulting current, torque or Kv is.
If you don't have a motor dyno and use lap times to tune then you inevitably end up playing a balancing act between motor timing and gear ratio. Adjusting the motor timing will change the Kv which can compensate for an inappropriate gear ratio. So if you are just adjusting motor timing and measuring lap times you may arrive at a motor timing that gets you the fastest time for your current gear ratio, however the timing will not be optimal for the motor to produce maximum power. With the motor timing adjusted for maximum power and the gear ratio adjusted for the resulting motor kv you will go even faster.
The only significance of the unloaded current measurement is that it is a rule-of-thumb to gauge if the motor is going to run blazing hot (if it measures like 20A+) and perhaps run down the battery too much over the course of a long race. If you only care for making power, you shouldn't care how much current it draws unloaded. However, if your battery runs down and decreases in voltage over the course of a race then motor power goes down too. Starting the race with slightly lower timing and therefore lower motor power but having the motor run much more efficiently (e.g. 6A unloaded current draw instead of 20A) may mean that the motor power doesn't fall off so much towards the end of the race. Then there is the possibility of using a higher capacity battery so the battery voltage doesn't drop as much over the race, keep the motor timing optimised for max power but have the weight penalty of the higher capacity battery...
06-06-2019, 11:13 AM
#54
Tech Master
Kv. absolute timing and unloaded current (amps) tell you nothing about how much power the motor makes. The only effect of kv is that you have to adjust your gear ratio to compensate for a difference in kv between different motors. Unless you are limited by the gear ratios you can run due to rules or physical configuration of the chassis you shouldn't care for what the kv of a motor is.
A 3000kv, 150watts motor will be faster than another motor which is 4000kv, 120watts once the gear ratio has been adjusted to suit. The only way to know how much power a motor is capable of is to 'sweep' the timing in fine increments (1degrees) and dyno at each timing. You then pick the timing which produces the maximum power, and don't care for what the resulting current, torque or Kv is.
If you don't have a motor dyno and use lap times to tune then you inevitably end up playing a balancing act between motor timing and gear ratio. Adjusting the motor timing will change the Kv which can compensate for an inappropriate gear ratio. So if you are just adjusting motor timing and measuring lap times you may arrive at a motor timing that gets you the fastest time for your current gear ratio, however the timing will not be optimal for the motor to produce maximum power. With the motor timing adjusted for maximum power and the gear ratio adjusted for the resulting motor kv you will go even faster.
The only significance of the unloaded current measurement is that it is a rule-of-thumb to gauge if the motor is going to run blazing hot (if it measures like 20A+) and perhaps run down the battery too much over the course of a long race. If you only care for making power, you shouldn't care how much current it draws unloaded. However, if your battery runs down and decreases in voltage over the course of a race then motor power goes down too. Starting the race with slightly lower timing and therefore lower motor power but having the motor run much more efficiently (e.g. 6A unloaded current draw instead of 20A) may mean that the motor power doesn't fall off so much towards the end of the race. Then there is the possibility of using a higher capacity battery so the battery voltage doesn't drop as much over the race, keep the motor timing optimised for max power but have the weight penalty of the higher capacity battery...
A 3000kv, 150watts motor will be faster than another motor which is 4000kv, 120watts once the gear ratio has been adjusted to suit. The only way to know how much power a motor is capable of is to 'sweep' the timing in fine increments (1degrees) and dyno at each timing. You then pick the timing which produces the maximum power, and don't care for what the resulting current, torque or Kv is.
If you don't have a motor dyno and use lap times to tune then you inevitably end up playing a balancing act between motor timing and gear ratio. Adjusting the motor timing will change the Kv which can compensate for an inappropriate gear ratio. So if you are just adjusting motor timing and measuring lap times you may arrive at a motor timing that gets you the fastest time for your current gear ratio, however the timing will not be optimal for the motor to produce maximum power. With the motor timing adjusted for maximum power and the gear ratio adjusted for the resulting motor kv you will go even faster.
The only significance of the unloaded current measurement is that it is a rule-of-thumb to gauge if the motor is going to run blazing hot (if it measures like 20A+) and perhaps run down the battery too much over the course of a long race. If you only care for making power, you shouldn't care how much current it draws unloaded. However, if your battery runs down and decreases in voltage over the course of a race then motor power goes down too. Starting the race with slightly lower timing and therefore lower motor power but having the motor run much more efficiently (e.g. 6A unloaded current draw instead of 20A) may mean that the motor power doesn't fall off so much towards the end of the race. Then there is the possibility of using a higher capacity battery so the battery voltage doesn't drop as much over the race, keep the motor timing optimised for max power but have the weight penalty of the higher capacity battery...
you can use the motolyzer to draw the efficiency and power curve unloaded. you can determine the power and efficiency curve on track and the difference between the 2 will have the same shape but current and rpm will be compressed.
timing doesnt seem to be effected by load or current but because of the compression to the curves from load it has to be different from loaded to unloaded. timing will shift power and efficiency around a little in the curve but its always less than what it had if it was set for the rpm it will be at. it reshapes the curve but at a very low efficiency.
06-06-2019, 08:43 PM
#55
Tech Master
a motor is also a generator at the same time its a motor. kv really describes when the voltage it generates equals the voltage you put in.
when the voltage generated equals the voltage given to the motor it doesnt spin faster anymore.
there are some losses and inefficiencies.
when 8 volts in equals 8 volts back emf or the voltage that is generated the motor doesnt go faster and your numbers support that and its why tuning to lap time is more useful to you.
its more useful because lap times take more power to decrease time. specifically more torque at the rpms you need. or more torque at the average rpm of a lap. gearing aligns the average rpm the track requires to the peak torque/rpms (power). this peak power (torque/rpms) is a bump on a curve. when you tune for time you are finding the top of this power bump.
there is another bump. its the efficiency bump. the efficiency bump is where the motor converts more current into torque and you get a cooler motor and power that is within 10-15 percent of peak power. between the coolest point and the torqeyist point is a combination of best lap time and coolest motor. it somewhere between the efficiency bump and the power bump. lap times and temperature tell you the peak of these two different bumps.
a motolyzer can show you the peak efficiency bump shape and peak power shape for an unloaded motor. when you load the motor the two shapes still apply except they will both simultaneously be 1/2 scale or 3/4 scale of the unloaded curves. both curves can be drawn by plotting amps per rpms. efficiency curve will be least amount of amps for every rpm the motor spins from 0 up to max rpm. once you have that based on setting your timing you are within 10-15% of the timing that will get you peak power. find peak power on the track and dont worry about heat. but dont set your timing below the timing you found in the peak efficiency test.
that last paragraph is what you work out with lap times and temperatures and doesnt require the motorlyzer if you do it well (which i know you do).
06-07-2019, 04:41 AM
#56
Tech Adept
Watch nick adams YouTube channel he test every part of the motors not the the bit on the low level motor checker
his dyno has a flywheel weight to load motors ,
have a watch of a few
https://m.youtube.com/channel/UCbiW6...LgAw&wlfg=true
his dyno has a flywheel weight to load motors ,
have a watch of a few
https://m.youtube.com/channel/UCbiW6...LgAw&wlfg=true
06-07-2019, 07:59 AM
#57
Correct.....Nick Adams tests as much as anyone can while sharing his findings. Other folks leave you in the dark !!!
06-07-2019, 08:33 AM
#59
This is all helpful, I am in the market for a new motor, not because I feel ill be faster with a new motor, but because my current one is going on its 4th race season. Its lost its punch it once had and isnt performing like it used to. I've used it a lot, and on my last race was over heating it even though I went down a pinion size. It's not as efficient as it was.
Hence why I need a new motor. Sounds like many of the new motors are all pretty close in perfotmance.
iam looking at an R1 and a friend recommended the muchmore (forget what they call it).
Hence why I need a new motor. Sounds like many of the new motors are all pretty close in perfotmance.
iam looking at an R1 and a friend recommended the muchmore (forget what they call it).
06-07-2019, 08:45 AM
#60
This is all helpful, I am in the market for a new motor, not because I feel ill be faster with a new motor, but because my current one is going on its 4th race season. Its lost its punch it once had and isnt performing like it used to. I've used it a lot, and on my last race was over heating it even though I went down a pinion size. It's not as efficient as it was.
Hence why I need a new motor. Sounds like many of the new motors are all pretty close in perfotmance.
iam looking at an R1 and a friend recommended the muchmore (forget what they call it).
Hence why I need a new motor. Sounds like many of the new motors are all pretty close in perfotmance.
iam looking at an R1 and a friend recommended the muchmore (forget what they call it).
