Which rotor did you select with the motor?

Ultra Select on the fantom facts machine 3 it gave a gauss reading of 1654/1642

curios as to what gearing and timing you ran?

Gauss readings are good, but I think rotor weight might have more effect on power than anything else...
Here are some of my rotor weight measurements:
Novak 12.3mm : 27grams
Novak 13mm : 30grams
Novak 14mm. : 35grams
R1 wurks v16 12.5mm : 25.3grams
Fleta 12.5mm steel : 26.3grams
Fleta 12.5mm titanium : 22.2grams(crazy rpm)
Novak HV 12.3mm : 44grams
Brushed 27t epic : 46grams
Brushed 19t epic : 60grams
Brushed 12x2 flatwire : 51grams
Such heavy weight on the brushed side, no wonder those magnets had to keep getting zapped, and power came late down the straight.... More mass vs less might reveal lots of hidden secrets... Hopefully the engineers will figure out the best rotor mass to make the most power, torque, etc, for the spec class.....

Rotor weight doesn't affect power output. It'll only affect spool up time, and it's fairly negligible compared to the inertia from the chassis.

Comparing rotor weights between brushed and brushless motors is also irrelevant, since on a brushed motor, the heavy component is the rotor while on a brushless motor, the heavy component is the stator. It's also not the reason why brushed motors had to be zapped. They used different kinds of magnets.

I think alot more testing needs to be done before we can say that rotor weight does not affect output power in a given size or whether the power will be at the bottom end or the top end....Although I can't really compare brushed to brushless, I can observe that in either case the more powerful rotors tend to weigh more on average and it is more prevalent in the brushless world than in the old brushed one... I know for a fact that the brushed motors with more winds(eg 7x3) had more power at the top end than a lower wind motor(eg 7x1) due to the two extra winds, eventhough the 7x1 would accelerate quicker...Two extra winds might weigh 15g or more. Would the effect be similar if compared two same size brushless rotors(12.5mm) except 15grams apart ??? Rotors are mainly classified in size, but should we also pay attention to weight as a tuning option ??? All I am suggesting is that rotor weight should also be taken into account, since the light titanium fleta rotors seem to increase kv exponentially, and that is a fact...
Ps: I've seen a few engineers even attempt hollow titanium motor shaft designs in an effort to reduce weight, eventhough it might be hard(not impossible) to do...Hopefully these light rotors can be used in 1/12 scale racing with reduced drivetrain weight.....

It's pretty simple Newtonian physics. Mass affects acceleration, not speed. You've been told that multiple times. The power output of the motor is the torque multiplied by the speed.

There have been true dyno tests done stating that it does affect speed. Specifically a lighter rotor will have more rpm a quicker acceleration and less torque. And similarly the opposite is true for a heavier rotor.

I think the scale is important in some of these 1to1 comparisons, because some of the stuff that we do in 10th scale really wouldnt work in a full sized racing car.

Is that actually because the rotor is lighter, or simply because there's less magnet involved? The behaviour you described sounds like a 12.3mm vs 12.5mm rotor. Assuming the magnet itself doesn't change in any way, I wouldn't expect additional mass on the rotor to affect torque or RPM at equilibrium.

The test i was referring to was a heavy rotor weight(12.5mm size) vs a lighter rotor weight (12.5mm size) Right if it was 12.3 vs 12.5 there is less material there, therefore what you said earlier is correct.

Correct, but I think it is important to note that a lighter rotor will accelerate quicker(0.2 sec quicker) by itself and probably slower under load if it has way less torque than the heavier rotor... I say it is best to have a heavier rotor and a lighter vehicle drivetrain: hopefully the drivetrain(minus the tires) could weigh exactly or close to the same as the rotor for the best possible Spec performance.... TC manufacturers are overbuilding their cars for mod racing, and they are not ideal for Spec performance: some of these car's drivetrain weigh over 90grams, wow.... I got my tc4's drivetrain down to about 50grams, and now I need a 40+ gram 12.5mm rotor in my 17.5t : that would be a total of 90grams rotating vs 112.2+grams in another vehicle with a fleta lightweight type rotor with less torque and less power.... Hopefully my dreams can come true ...lol...I am counting on the Fantom Team to deliver....
In addition, some magnets might weigh more than others. Will the weight difference unleach some more power ??? I guess the weight scales will be working overtime to get that extra 40 watt of power over all the other motor manufacturers...Taking weight off the chassis to add weight in the rotor might be the way of the future....Cheers...

Acceleration being about equal, then mass is the only variable left in the well known equation: E=mc2....
The strongest magnet vs the heaviest magnet.....
The stronger magnet reducing rpm might not produce as much power as a heavier but weaker magnet that runs at a much higher rpm... It is all about increasing the stored energy in the rotor through a compromise between mass(shaft+magnet) and high enough rpm(ideal gauss level) in a motor that is built right at the current Roar limits....

13.5 V3 has been ordered.

What's the latest on ROAR approval? Was hoping to see see info in this thread.

Who has the inside scoop?

E=mc2? We're not racing at relativistic speeds. Only classical Newtonian physics applies here.

No bert, e=mc^2 has nothing to do with motors.