Ohbse wrote:Nice work Doc, cool to see some actual testing of a high performance bike! It's definitely dishing out some serious torque, I guess it's incredibly unlikely to see loads like that in use on the street as you'd loop it over well before 100lb/ft could be applied to the ground.
As well as agreeing with Allex that a comparison with Cro/Qs would be awesome I have a little bit of a wish list for other testing if ever you get the opportunity..
Effect of PWR timing on wheel torque - Dyno is the only real way to quantify an improvement as the 'butt dyno' is not going to be much help at this power to weight level. How much advance is beneficial? At what point does torque go DOWN? Does this have a negative effect on efficiency? Initial timing etc could also be 'tuned' for both power and efficiency ideal compromise using a dyno for comparative data.
OVS - my understanding is this could potentially extend your power curve to a higher RPM limit before reaching the 'knee' we see in the graph. In your case this probably would not assist in the real world as your KV is so high, meaning you would be aero limited well before this effect would be the bottleneck, however it's very applicable for people running a Cromotor with standard KV over 70 km/h.
More current! There have been examples of russian guys tuning beyond the inbuilt limitations. Never has pushing beyond the limits been so easy for you! just flash unlocked firmware and away you go. Key to keeping this alive is thermal management, a topic you no doubt know a lot about. There's good opportunity to greatly increase thermal mass and ability to reject heat from the FET's, perhaps even internal ventilation to assist with other components longevity. Additional caps, Upgrade of phase wires to 8ga etc all possible to increase power potential. 180 amps battery, 400 phase should truly stretch your motor to the limit.
I'm sure you're busy and may not have a chance to do all this, but perhaps somebody does. When I receive my Max-e back from Russia I will see if I can locate a suitable dyno locally and do some testing of my own
Actually there is no tuning on the Max-E.. all stock parameters and autodetect has been set. but i was still able to get 10.5hp at the wheel with a single old outdated 5302 witch is already awsome i think. Once i have better weather here ( spring and summer) i'll have alot more occasion to tune it perfectly and they unlock it as well, but i'm going easy first then step by step i'Mll raise the tuning to next level of performances.
I predict that the Max E will probably overheat in real world use of 22s 130A batt current on teh road because the KV of that motor is just really high and inductance is so low too... so this 5302 is in fact a controller killer ... but as you said a good thermal management like thermal mass or adding fins to take profit of the wind will help.
I will also try my liquid cooled 5403 later maybe in end of april or may. I will also receive my custom cromotor.
I would like to have one bike for the road and one for the offroad... so i am not decided yet witch bike will be offroad equiped.. the Giant or the NYX...
My giant look mad max as well and the NYX look professional grade , sexy and high tech...
I have tried OVS set to about 5 with the 5302 with empty 22s and i still get 188kmh max no load speed. but when these are fully cahrged i also get 188kmh max no load speed witch make me believe that the controler is triggering speed limit. I have tried to set higher value than 188kmh but when i do that the speed limit actually reduce.. witch is something i dont understand with teh Max E and RC9e firmware.
Usually you get your peak power at the speed that correspond to hald the max no load speed ( thumb rule i'm using) so it the max speed is really 188kmh with this setup then i should get max power peak to about 94kmh witch make me believe that with thsi actual setup^, the powerband should be pretty impressive with all that acceleration sustained up to that speed !
I already experienced more torque/ trust than 120lb-ft with my old 5305 and a 20" wheel on 24s i had... this was my setup that towed a 19200 lb schoolbus. I had about 170 pounds of trust! witch was TERRIBLE test for the epoxy bonded Ultimate Torque arms !!! but they did the job perfectly !! that was about 1700 pound of force applied on both each of the 4 axel edges at 6mm radius from the center.