Re: Water / Meth injection - $200 bounty
Posted: Sat Aug 29, 2020 10:02 am
Well, in arduino max PWM is 255(100% output), sadly speeduino is using its own custom code to generate pwm which max value is only 100(100% output), anything above 100(101-255) is limited to 100. So TS config is ok.
Closed loop wmi was not as much tested as different modes, its depend on fuel injector PW to calculate wmi PW.
Lets see what number we should put in wmi table to get some reasonable results.
Closed loop is calculated like that:
wmiPW = (PW + wmiOffset) * 10 * wmiTable(MAP, RPM) / 100
Lets assume that:
RPM = 6000
Map = 150 kpa
PW = 20ms
wmiOffset = 0ms
And we want to find table cell value that will give as wmi max pwm value of 100:
wmiPW = 100
100 = (20 + 0) * 10 * wmiTable(MAP, RPM) / 100
100 = 20 * 10 * wmiTable(Map, RPM) / 100
100 * 100 = 20 * 10 * wmiTable(Map, RPM)
(100 * 100) / (20 * 10) = wmiTable(Map, RPM)
wmiTable(Map, RPM) = 50
wmiTable(150, 6000) = 50
That's mean that to achieve 100% wmi PWM at 6000RPM, 1.5Bar load and injector PW of 20ms you need to have value 50 in table, anything below that will limit wmi PWM, anything above will still be 100%.
My advice would be to use open loop, which is much easier to tune and use.
Closed loop wmi was not as much tested as different modes, its depend on fuel injector PW to calculate wmi PW.
Lets see what number we should put in wmi table to get some reasonable results.
Closed loop is calculated like that:
wmiPW = (PW + wmiOffset) * 10 * wmiTable(MAP, RPM) / 100
Lets assume that:
RPM = 6000
Map = 150 kpa
PW = 20ms
wmiOffset = 0ms
And we want to find table cell value that will give as wmi max pwm value of 100:
wmiPW = 100
100 = (20 + 0) * 10 * wmiTable(MAP, RPM) / 100
100 = 20 * 10 * wmiTable(Map, RPM) / 100
100 * 100 = 20 * 10 * wmiTable(Map, RPM)
(100 * 100) / (20 * 10) = wmiTable(Map, RPM)
wmiTable(Map, RPM) = 50
wmiTable(150, 6000) = 50
That's mean that to achieve 100% wmi PWM at 6000RPM, 1.5Bar load and injector PW of 20ms you need to have value 50 in table, anything below that will limit wmi PWM, anything above will still be 100%.
My advice would be to use open loop, which is much easier to tune and use.