Just got back in from testing in the garage. I posted in the VESC forum, but I'll copy and paste the same post here (too much data to re-type):
"Just got back in from the garage. We're making some progress. And it's starting to look like Frank was right (sorry for doubting you, Frank). With the new gearing, running the compressor into choke (i.e. max load) we were able to hold 9.1 kW and hit 18,900 impeller rpm (72,917 eRPM to be specific; 6 pole motor = 24,305 motor rpm * pulley ratio of .778 = 18,909 impeller RPM). Voltage was pretty solid at 58.5 volts (my batteries are monsters - at 60lbs (27 kg) they should be - unloaded voltage was just under 62). Battery current was holding steady at 155-156 amps. The motor current was the limiting factor - I had it set at 300 motor amps, and it got there and just sat there. Duty cycle was also pretty stable at 61%. The only thing that got above ambient was the belt. As I would expect pushing 9kW of energy through it. And it was just a little warm to the touch (maybe 20-25* C).
I'm not too concerned about the performance with the compressor in choke - it'll never run there on the car; so this is just a durability test. Just out of curiosity, what's the max I should run the motor current at? At 300 motor amps, it's a little high for the motor. At 95% duty cycle, however, that would put us at 285 motor amps, which is about it's rated max. Obviously, the best thing to do would be to find the optimal pulley ratio that's the best compromise on the running car. But that I need to test on the dyno - testing on a public street is far too dangerous. I probably should also machine the bore on the 16 tooth pulley and see if that gives us better on car performance; but once again, right now it looks like the 14 tooth pulley is our friend (also Frank's suggestion). Especially since there's so little voltage drop."
"Just got back in from the garage. We're making some progress. And it's starting to look like Frank was right (sorry for doubting you, Frank). With the new gearing, running the compressor into choke (i.e. max load) we were able to hold 9.1 kW and hit 18,900 impeller rpm (72,917 eRPM to be specific; 6 pole motor = 24,305 motor rpm * pulley ratio of .778 = 18,909 impeller RPM). Voltage was pretty solid at 58.5 volts (my batteries are monsters - at 60lbs (27 kg) they should be - unloaded voltage was just under 62). Battery current was holding steady at 155-156 amps. The motor current was the limiting factor - I had it set at 300 motor amps, and it got there and just sat there. Duty cycle was also pretty stable at 61%. The only thing that got above ambient was the belt. As I would expect pushing 9kW of energy through it. And it was just a little warm to the touch (maybe 20-25* C).
I'm not too concerned about the performance with the compressor in choke - it'll never run there on the car; so this is just a durability test. Just out of curiosity, what's the max I should run the motor current at? At 300 motor amps, it's a little high for the motor. At 95% duty cycle, however, that would put us at 285 motor amps, which is about it's rated max. Obviously, the best thing to do would be to find the optimal pulley ratio that's the best compromise on the running car. But that I need to test on the dyno - testing on a public street is far too dangerous. I probably should also machine the bore on the 16 tooth pulley and see if that gives us better on car performance; but once again, right now it looks like the 14 tooth pulley is our friend (also Frank's suggestion). Especially since there's so little voltage drop."