1000 was a WAG, I ordered a Sentry (was going to build one but heck, its cheaper than I could probably bring one together for
and will gather data.
I assumed (have not put it up on a scope yet) that the coils field strength is controlled by a high-speed pulse, same as traditional brushed motors. I meant increase that duty cycle so as to raise the input power higher than that throttle setting would normally call for, resulting in the RPMs the driver is calling for, but at a higher torque.
Yes, just like the good old brushed esc's the fets still operate at "x" frequency and are PWM for variable speed. However, there are 3 "banks" of these fets; one for each phase on the motor. I see what you meant by spike the duty cycle, but the esc's are already firing each phase as long as possible (120 degrees of rotation) before moving on to the next. Basically they are already doing what you want to the max. At full throttle the only switching going on is between each bank for each phase and the operating frequency of the fets is moot.
Let me try and put it another way.
Its my understanding that as timing advances, maximum RPM can be raised but at the cost of torque and with the back EMF heating up the motor. In yesteryear, the compromise was: enough advanced timing to increase top end, but not so much that the motor overheats and has no low-end torque. For this reason motors are still shipped with X amount of advanced timing, with no assumptions about what the ESC will add.
Here's what catches everyone with timing. Less timing does not mean more torque at all rpms. There is a "perfect" degree of timing for every rpm range of the motor and any less timing than that results in less torque and less current and more timing results in less torque with more current (which is the cause of most heat). The standard timing is the best average "overall" timing for the entire rpm range. Lets say at 0 rpm the perfect timing is, well, 0 for the most torque (it actually tends to be somewhat past zero on our wye wound motors). Now at 1000 rpm you would actually be losing torque running zero timing. The question everyone trying to find out with testing various setups is "what degree is optimal?" Thats where the boost ramps are played with for hours on end. lol
But times have changed dramatically; no compromises are necessary, we can change the timing in software to suit what the driver is calling for at any isntant in time. Great. Except why start at X? why not start at neutral where torque is maximized?
If you check most RS setups everyone is reducing their timing on the Redline motors around 0 to 10 degrees depending on how much low end torque they want. Its just easier programing wise to set the motor at the minimum required rpm and just call on software to add timing.
Coming out of a corner I am far more interested in torque than potential top speed, I would like the ESC to retard the timing [from the factory setting of, say 15 degrees] all the way to 0, and increase the power delivery from the battery so I have a smooth increase of throttle, but with much more available torque.
See above.
THEN blast the timing up to 50+ degrees for the [short] straight following the corner, and maybe even ramp it up to 80 or 90 (or whatever) for a long straight.
Follow? All I see in my Tekin manual is how to increase the timing. I am prepared to retard the bell on my Ballistics all the way to zero to simulate these effects, but not if giants have gone before me and found it to be pointless.
This is just what most setups do. The big issue most people are running into now is that the timing scheme between manufacturers is not equivalent at all.