Had a little test-drive today: motor power has evolved a bit faster than my driving skill and it was a very big switch to get used to after having mainly played low-speed off-road lately :D.
Ran 42/42 gearing for a no-load speed of 185 kph @ 3.7V/cell on 6S, based on measured 1510 kv. Wanted to run 2 6S packs and 1 7S pack, but had to stop halfway the second 6S pack, because the gears (both pinion and spur) came loose and got chewed-up a bit. Had some throttle glitches in the beginning, with sudden brake pulses while accelerating, which might have been a contributing factor to that, but I think all-in-all the tiny M3x6 screws holding the gears to the spur mounts are just too small. Have to see how I fix that. On the spur-side, I can add lock-nuts, but on the pinion-side there's not any space for that... to be continued...
Anyway, the important part: managed to get it up to 160 kph; motor wasn't breaking a sweat: max temp I saw was 48°C @ 17°C ambient, but I was changing settings a lot and not driving continuously. When everything is dialed in and with some more space and practice, I will be able to push it harder and temps will obviously rise, but from what I can tell so far, I think this motor won't become the bottleneck and I will be killing my batteries before the motor. Looking at the log data, I think I never really reached steady-state speed (need a bit more space and guts for that); data shows peak RPM was about 29-30k. Taking into account the Voltage sag (from ~3.9 to 3.4 V/cell) in the data from the 160 kph run (see below), it means the motor was running at ~94% of it's no-load kv under ~150-160A load, I think that's pretty good performance, and I am a bit relieved I did not immediately run in to the 60k ERPM mother-of-all-efficiency-walls. I started with 4 degree timing (found some info from Neu on timing settings, although not sure whether 100% applicable to 56mm dia 6-poles:
http://www.neumotors.com/NeuMotors/FAQs_%26_setup.html), but switched back to 0 after I experienced some glitches in throttle response, which I thought might caused by the timing; turned out it wasn't, but left the timing at 0 nevertheless, as it ran well and I already had all the speed I could handle.
@ Lizard: what timing did you run on your TP5840? Maybe wrong timing could be a factor in your resluts with it? Having seen how my TP5660 roars, I can't imagine yours not being able to top the TP4070, unless it's faulty.
What is a bit bothersome is the ripple Voltage under throttle ramp-up. I thought the amount of Current draw is what causes ripple, bit it seems it's more the combination of high draw, low duty-cycle... maybe I should practice ramping throttle up quicker, in order to get to higher duty-cycles faster, but then peak Currents will increase again, and there's only so much power the wheels can put on the road anyway before losing traction... so I'll also see if I can fit some more caps easily.
Gave the 2015 GRP tires another try (S3 compound this time), but they really suck balls and caused many near-misses and very high blood-pressure, in a bad way :), even hit my new camera tripod again, skating over the asphalt... luckily no major damage, but driving with those tires on a narrow street, is more scary than fun. Doing burnouts until they started to melt helped a bit to increase stickiness, but as soon as they got cold again it was back to drifting. Hope they go back to 2014 compound next year, or introduce some S0s.
Anyway, pics or it didn't happen:
New personal record:
Whe needs a body when you can have THIS instead:
160 kph run, with Torque Control on 5:
150 kph run, with TC on 4:
Loose gears:
Throttle glitches (sudden brake pulses out of nowhere...)
Settings:
Small video - not much but at least gives a bit of an impression of how it drives:
[YOUTUBE]-u0wiBMkxmE[/YOUTUBE]
Also realized I hadn't even bothered to check ESC temps:
