datalogging

datalogging

How to datalog

 

When developping a tuningfile logging data is absolutely necessary. It is even more important than doing dyno runs.

Always start with a baseline of the complete original car. This is needed to see how the car responds in the normal OEM condition. Is there a problem shown in OEM condition, then stop the project and first solve the issue before going further.

 

The channels to log are:

 

engine speed – rpm

pedal postion

engineload

trottle body postion

intake manifold pressure

boost pressure request

boost pressure actual

wastegate dutcycle

lambda request

lambda actual

injection in milligrams

injector pulsewidth

railpressure

mass air flow

intake air temperature

oil temperare

water temperature

exhaust gas temperature

Ignition per cylinder

Ignition adaption (advancement/retarding)

Knock voltage

Cam phasing

 

The best way to show all this data is to store data as excesheet

See example below

 

                               
    Engine Load Engine Load Engine Load Boost Pressure   Engine Speed Engine Load Boost Pressure Boost Pressure   Engine Speed Coolant Intake Air Ignition
  CZAS (specified) (spec. corrected) (actual Value) Control (N75) CZAS (G28)   (specified) (actual) CZAS (G28) Temperature (G62) Temperature (G42) Timing Angle
    % % % %   /min % mbar mbar   /min *C *C *PGMP
  0,03 94,7 92,5 29,3 95,7 0,06 1080 36,1 1190 990 0 1080 93 48 27
  0,12 97 92,5 45,1 96,1 0,15 1120 48,1 1080 990 0,09 1080 93 48 5,3
  0,21 96,2 95,5 52,6 95,3 0,25 1080 53,4 1160 1000 0,18 1080 93 49 13,5
  0,31 97,7 94 54,9 100 0,34 1120 58,6 1420 990 0,28 1120 93 49 12,8
  0,4 99,2 97 64,7 100 0,43 1160 65,4 1440 1000 0,37 1160 93 49 6,8
  0,5 102,3 98,5 66,9 100 0,53 1200 66,9 1470 1010 0,46 1160 93 49 7,5
  0,59 102,3 100 67,7 100 0,62 1240 68,4 1490 1010 0,56 1200 93 49 6
  0,68 104,5 101,5 68,4 100 0,71 1280 69,2 1520 1020 0,65 1240 93 49 4,5
  0,78 106 103 69,2 100 0,81 1320 69,9 1530 1040 0,75 1280 93 48 5,3
  0,87 109 104,5 69,9 100 0,9 1320 69,9 1530 1050 0,84 1320 93 48 5,3
  0,96 110,5 107,5 70,7 100 1 1400 71,4 1570 1060 0,93 1360 93 48 5,3
  1,06 112,8 110,4 71,4 100 1,09 1400 71,4 1590 1070 1,03 1400 93 48 5,3
  1,15 115 110,4 72,2 100 1,18 1440 72,2 1600 1080 1,12 1400 93 48 6,8
  1,25 116,5 113,4 72,9 100 1,28 1480 72,9 1630 1090 1,21 1440 93 48 15,8
  1,34 117,3 113,4 72,9 100 1,37 1480 72,9 1650 1100 1,31 1480 94 48 15
  1,43 119,5 114,9 74,4 100 1,46 1520 74,4 1680 1110 1,4 1520 94 48 15
  1,53 121,1 117,9 75,2 100 1,56 1560 75,2 1700 1120 1,5 1520 93 47 15
  1,62 123,3 119,4 75,2 100 1,65 1560 75,9 1720 1130 1,59 1560 93 47 12
  1,71 124,8 120,9 75,9 100 1,75 1600 76,7 1730 1140 1,68 1560 93 47 15
  1,81 126,3 122,4 76,7 100 1,84 1600 76,7 1750 1140 1,78 1600 94 46 12
  1,9 127,8 123,9 77,4 100 1,93 1640 77,4 1760 1150 1,87 1600 94 46 12
  2 129,3 125,4 77,4 100 2,03 1640 78,2 1770 1160 1,96 1640 93 46 12,8
  2,09 130,1 125,4 78,2 100 2,12 1640 78,2 1780 1170 2,06 1640 94 46 12,8
  2,18 131,6 126,9 78,9 100 2,21 1680 78,9 1800 1180 2,15 1680 94 46 12,8
  2,28 133,8 128,4 78,9 100 2,31 1680 79,7 1820 1180 2,25 1680 93 46 12,8
  2,37 135,3 129,9 78,9 100 2,4 1720 78,9 1830 1190 2,34 1680 94 45 12,8
  2,46 136,8 132,8 79,7 100 2,5 1720 79,7 1840 1200 2,43 1720 94 45 12
  2,56 138,3 132,8 80,5 100 2,59 1760 80,5 1850 1200 2,53 1720 94 45 12
  2,65 139,8 134,3 80,5 100 2,68 1760 80,5 1860 1210 2,62 1760 94 45 12
  2,75 141,4 135,8 81,2 100 2,78 1800 81,2 1880 1210 2,71 1760 94 45 12
  2,84 141,4 137,3 82 100 2,87 1800 82 1890 1220 2,81 1800 94 45 12
  2,93 143,6 138,8 82,7 100 2,96 1840 82,7 1920 1230 2,9 1840 94 45 11,3
  3,03 145,1 140,3 83,5 100 3,06 1840 83,5 1930 1240 3 1840 94 45 11,3
  3,12 146,6 141,8 84,2 100 3,15 1880 85 1940 1250 3,09 1880 94 45 11,3
  3,21 148,1 143,3 85 100 3,25 1920 85,7 1950 1260 3,18 1880 94 45 11,3
  3,31 150,4 144,8 86,5 100 3,34 1920 86,5 1970 1270 3,28 1920 94 45 12
  3,4 151,1 146,3 86,5 100 3,43 1960 87,2 1990 1280 3,37 1920 94 45 11,3
  3,5 151,9 147,8 87,2 100 3,53 2000 88 2000 1290 3,46 1960 94 45 10,5
  3,59 152,6 147,8 88,7 100 3,62 2000 88,7 2000 1300 3,56 2000 94 45 12
  3,68 153,4 149,3 89,5 100 3,71 2040 90,2 2000 1320 3,65 2000 94 45 11,3
  3,78 154,1 149,3 91 100 3,81 2040 91 2000 1330 3,75 2040 94 45 11,3
  3,87 154,9 150,7 91 100 3,9 2080 91,7 1990 1340 3,84 2080 95 45 12
  3,96 156,4 150,7 91,7 100 4 2120 91,7 2000 1350 3,93 2080 95 45 12
  4,06 157,1 152,2 92,5 100 4,09 2160 92,5 1980 1370 4,03 2120 94 45 12,8
  4,15 157,9 153,7 93,2 100 4,18 2160 93,2 1970 1380 4,12 2160 95 45 12,8
  4,25 158,6 153,7 94,7 100 4,28 2200 94,7 1970 1400 4,21 2160 94 45 10,5
  4,34 159,4 155,2 95,5 100 4,37 2240 96,2 1950 1410 4,31 2200 94 45 9,8
  4,43 160,2 155,2 96,2 100 4,46 2240 96,2 1940 1430 4,4 2240 94 45 11,3
  4,53 160,2 156,7 97 100 4,56 2280 97 1930 1440 4,5 2280 94 45 8,3
  4,62 160,9 156,7 97 100 4,65 2320 97,7 1940 1460 4,59 2280 94 44 9,8
  4,71 160,9 156,7 98,5 100 4,75 2360 98,5 1920 1480 4,68 2320 94 44 10,5
  4,81 161,7 156,7 100 100 4,84 2400 100 1890 1510 4,78 2360 94 44 8,3
  4,9 161,7 158,2 101,5 100 4,93 2400 101,5 1890 1520 4,87 2400 95 44 9,8
  5 162,4 158,2 103 100 5,03 2440 103 1870 1540 4,96 2440 94 44 9
  5,09 162,4 158,2 104,5 100 5,12 2480 105,3 1870 1560 5,06 2480 95 44 8,3
  5,18 163,2 158,2 106 100 5,21 2520 106,8&a

 

as you can see this way it is very easy to see how the engine is performing at a specific rpm and pedal position.

 

Depending on the project a different of driving is needed during the logging.

 

In case of tuning the OEM ecu and OEM engine a WOT (Wide Open Trottle) run in 3rd gear give good information for making a proper tuning.

 

On dyno: make sure engine is working on normal operating temperature. Set correct load value, arrange proper cooling by a fan which simulates real driving wind on the engine, intercooler, but also under the car to cool the exhaust. Set ambient correction to DIN values

 

On road: find a good safe quiet piece of road where you can test safely. Note the current ambient pressure, temperature and humidity we have to take this into account when analizing the data.

 

The biggest problem for datalogging many cars is that there are not enough channels available to log.

 

Beneath we will give a list of channels which are minimally necessary

 

always rpm

 

always pedal position or engineload to see what the driver requests of the engine

 

For turbo petrol engines we need to see actual boost before and after tuning. If boost actual is not available at least measure intake manifold pressure

 

For turbo diesel engines we need to see at least njection in milligrams or even better injector pulsewidth

 

For all petrol engines we need to see actual lambda. If no obd data available an external lambda sensor in exhaust is last resort. In case of older cars the external widebandlambda sensor is even better since old cars many times have the narrowband lambda sensors installed on the car which are not accurate on a WOT run. Ofcourse the ecu knows this and when going WOT the ECU does not use the lambda sensor to control fuel but instead uses the fuel maps inside the ecu. So when a narrowband sensor is installed and you logged this data during WOT, remember not to use this data.

 

For all petrol engines we need to see ignition or even better ignition adaption. Ignition adaption allows us to see the ecu correcting ignition according to knock and temperatures.