Is this good RPM?

[mavrick0611]

I just got a 10x3 motor and am going to race in very mild competitive local races. And at a constant 6 volts my motors highest RPM Rating is 36,600 RPMs (600 and something) IS this a good RPM rating for local mild races?
thanks!
aj

[mavrick0611]

its an integy v8 jetta. i ran it the other night and it seemed alot faster than my reedy pulse r 10x2 did. as long as it gets the job done.
aj

[tc3guy]

Mavrick,
what motor do you have? If thats a speed gem its probably ok but if its a D4 or a reedy fury thats a lower RPM than usual.

[jeepinator]

What are you measuring it with ? Or are you using the specs ?
No load RPM means absolutely nothing, BTW.
I have dyno'd like 8 million motors. No matter how much I think I understand the motor I am testing, or how I interpret the "data", the dang motor seems to perform differently in real world situations than I would have expected. I pretty much don't use the dyno any more.
Batteries, brushes, timing, and gearing all can make a profound difference on the characteristics of a given motor.
You have not really provided enough info to make an assesment anyway ...

[mavrick0611]

ok, when i get home, (im in indianapolis right now) ill type up that little paper that it was dynoed on and post it.
aj

[jeepinator]

There have been dynos that use a flywheel for load. They work on the principle that if you give the test motor X amount of energy and a known mass is accelerated to Y RPM in Z amount of time you can calculate everything necessary (Efficiency, power output, etc). These type of dynos seem to make the most sense to me, but the majority have not been of this type.
The more common aproach to dyno design is to use a slave motor to provide load. The slave motor is loaded applying a variable resistance (electrical) accros the connection terminals. The slave motor and the test motor are mechanically coupled at the output shafts. This is where the RPM sensor is placed as well. I think most designs have used optical mechanisms to determine RPM. The coupling has "paddles", for a lack of a better description, on it to block a beam of light once or twice a rotation.
Anyway, I have one of the cheaper dynos. It is the Tekin DYN900. I doubt they still make it. It is the salve motor type.
I found that the dyno worked best when comparing the motor to itself (using different brushes, timing, etc) than comparing one motor to another. Still, though, I would work on a motor all night to gain the most RPM at full load out of a stock motor only to find it was a dog at the track. Sometimes this could be fixed with gearing, but sometimes I would just go hmmmm ...
Maybe I am just not smart enough ;)

[chizzler]

i find your theory of the donut-shaped universe intriguing...... :D :D

[Leet TC3]

Testing a stock motor, or any motor with advanced timing, with no load is pretty worthless.

But, correct me if I'm wrong, I thought Dynos use flywheels, etc., to simulate loads?

I realize that this still isn't "real world". But it would serve a purpose of comparing the same model motors, and it would allow you to test various springs, brushes etc. to find the best combination for a particular motor.