a few updated EvoScan definitions
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From: Tri-Cities, WA // Portland, OR
a few updated EvoScan definitions
I made an attempt to derive better correlations for the coolant temperature and MDP.
coolant temperature (deg F): -1.24x + 222
I got this correlation by measuring the EvoScan raw output in the morning after the engine had cooled down to ambient temperature overnight, and then assuming that the coolant temperature was around 185 F at normal operating temperature (as mentioned by a few people using pocket loggers).
MDP (bar): -0.00495x-1
Got this by measuring the raw value with the engine shut off and then with the engine idling. I correlated the values to the values on my MR boost gauge. When using this correlation, the value from EvoScan tracks my boost gauge up to 0.2 bar, and after that the boost gauge keeps going, but EvoScan stays a 0.22 bar (which is expected for the USDM ECU and pressure sensor).
coolant temperature (deg F): -1.24x + 222
I got this correlation by measuring the EvoScan raw output in the morning after the engine had cooled down to ambient temperature overnight, and then assuming that the coolant temperature was around 185 F at normal operating temperature (as mentioned by a few people using pocket loggers).
MDP (bar): -0.00495x-1
Got this by measuring the raw value with the engine shut off and then with the engine idling. I correlated the values to the values on my MR boost gauge. When using this correlation, the value from EvoScan tracks my boost gauge up to 0.2 bar, and after that the boost gauge keeps going, but EvoScan stays a 0.22 bar (which is expected for the USDM ECU and pressure sensor).
Last edited by mrfred; Sep 4, 2006 at 09:09 AM.
If you want, extract the DATA.XML file from my Log Analyzer for Evoscan, and update the XML, and upload it to this thread.. Or E-mail it to me.. I'll make sure both the zip and other locations are updated after you guys can verify its as close to correct as its gonna get..
FWIW on the US car, MDP is going to be a max of 14.7psi absolute (1 bar) where an absolute vacuum would be 0psi, and sea level would be 14.7psi..
Hopefully you took that into account when you created your conversion.. The highest it should read is just over 1 bar.. since it does have some variance for slightly below sea level (and high pressure weather at the same time)
Hopefully you took that into account when you created your conversion.. The highest it should read is just over 1 bar.. since it does have some variance for slightly below sea level (and high pressure weather at the same time)
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Yep, my MDP correlation will read 0 bar when the engine is not running (ign ON). I'm at 300 ft above sea level.
I'm pretty sure that the MDP correlation is right on the money, but I'd like to better correlate the coolant temperature, maybe next weekend. If possible, I want to disconnect the sensor and correlate it using a pot of boiling water.
Everyone seems to be assuming that the correlations are linear functions. Is that a reasonable assumption?
I'm pretty sure that the MDP correlation is right on the money, but I'd like to better correlate the coolant temperature, maybe next weekend. If possible, I want to disconnect the sensor and correlate it using a pot of boiling water.
Everyone seems to be assuming that the correlations are linear functions. Is that a reasonable assumption?
Last edited by mrfred; Sep 4, 2006 at 09:09 AM.
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From: UK
Code:
Engine coolant and intake air temperature ;* ------------------------------------------ ;* ;* Approximate sensor curves (temperature ;* against ADC value, taken from MMCD). The ;* control points in the service manual are ;* quite close (0 to 2 degC off). ;* ;* ;* ADC ECT IAT ADC ECT IAT ADC ECT IAT ADC ECT IAT ;* degC degC degC degC ;* ;* $00 158.0 184.0 $40 52.0 56.0 $80 21.0 23.0 $c0 -7.0 -7.0 ;* $01 154.4 178.1 $41 51.3 55.3 $81 20.6 22.5 $c1 -7.5 -7.6 ;* $02 150.9 172.5 $42 50.7 54.6 $82 20.2 22.1 $c2 -8.1 -8.2 ;* $03 147.5 167.2 $43 50.1 53.9 $83 19.8 21.7 $c3 -8.6 -8.8 ;* $04 144.2 162.0 $44 49.5 53.3 $84 19.4 21.2 $c4 -9.2 -9.4 ;* $05 140.9 157.1 $45 48.9 52.6 $85 19.0 20.8 $c5 -9.8 -10.1 ;* $06 137.7 152.4 $46 48.3 52.0 $86 18.7 20.4 $c6 -10.4 -10.7 ;* $07 134.6 148.0 $47 47.7 51.3 $87 18.3 19.9 $c7 -10.9 -11.3 ;* $08 131.6 143.7 $48 47.2 50.7 $88 17.9 19.5 $c8 -11.5 -12.0 ;* $09 128.6 139.6 $49 46.6 50.1 $89 17.6 19.0 $c9 -12.1 -12.6 ;* $0a 125.7 135.7 $4a 46.1 49.4 $8a 17.2 18.6 $ca -12.7 -13.2 ;* $0b 122.9 132.0 $4b 45.6 48.8 $8b 16.9 18.2 $cb -13.2 -13.9 ;* $0c 120.2 128.5 $4c 45.0 48.2 $8c 16.5 17.7 $cc -13.8 -14.5 ;* $0d 117.5 125.1 $4d 44.5 47.7 $8d 16.1 17.3 $cd -14.3 -15.1 ;* $0e 114.9 121.9 $4e 44.0 47.1 $8e 15.7 16.8 $ce -14.9 -15.7 ;* $0f 112.4 118.8 $4f 43.5 46.5 $8f 15.3 16.4 $cf -15.4 -16.3 ;* $10 110.0 116.0 $50 43.0 46.0 $90 15.0 16.0 $d0 -16.0 -17.0 ;* $11 107.6 113.2 $51 42.4 45.4 $91 14.5 15.5 $d1 -16.5 -17.6 ;* $12 105.3 110.6 $52 41.9 44.9 $92 14.1 15.1 $d2 -17.0 -18.2 ;* $13 103.0 108.1 $53 41.4 44.3 $93 13.7 14.6 $d3 -17.5 -18.8 ;* $14 100.8 105.8 $54 40.9 43.8 $94 13.3 14.2 $d4 -18.0 -19.4 ;* $15 98.7 103.5 $55 40.4 43.3 $95 12.9 13.7 $d5 -18.6 -20.1 ;* $16 96.7 101.4 $56 39.9 42.8 $96 12.4 13.3 $d6 -19.2 -20.8 ;* $17 94.7 99.4 $57 39.3 42.3 $97 12.0 12.8 $d7 -19.8 -21.5 ;* $18 92.8 97.5 $58 38.8 41.8 $98 11.5 12.4 $d8 -20.5 -22.3 ;* $19 91.0 95.7 $59 38.3 41.4 $99 11.1 12.0 $d9 -21.3 -23.1 ;* $1a 89.2 93.9 $5a 37.8 40.9 $9a 10.6 11.5 $da -22.1 -24.0 ;* $1b 87.5 92.3 $5b 37.3 40.4 $9b 10.2 11.1 $db -23.0 -24.9 ;* $1c 85.9 90.7 $5c 36.9 39.9 $9c 9.7 10.7 $dc -24.0 -26.0 ;* $1d 84.3 89.2 $5d 36.4 39.4 $9d 9.3 10.2 $dd -25.0 -27.1 ;* $1e 82.8 87.7 $5e 35.9 38.9 $9e 8.8 9.8 $de -26.2 -28.3 ;* $1f 81.3 86.3 $5f 35.4 38.4 $9f 8.4 9.4 $df -27.5 -29.6 ;* $20 80.0 85.0 $60 35.0 38.0 $a0 8.0 9.0 $e0 -29.0 -31.0 ;* $21 78.6 83.6 $61 34.5 37.5 $a1 7.5 8.5 $e1 -30.5 -32.5 ;* $22 77.4 82.4 $62 34.0 37.0 $a2 7.1 8.1 $e2 -32.2 -34.1 ;* $23 76.2 81.1 $63 33.6 36.4 $a3 6.6 7.7 $e3 -33.9 -35.7 ;* $24 75.0 79.9 $64 33.1 35.9 $a4 6.2 7.3 $e4 -35.8 -37.5 ;* $25 73.9 78.8 $65 32.7 35.4 $a5 5.8 6.9 $e5 -37.7 -39.3 ;* $26 72.9 77.7 $66 32.3 34.9 $a6 5.3 6.4 $e6 -39.7 -41.2 ;* $27 71.9 76.6 $67 31.8 34.4 $a7 4.9 6.0 $e7 -41.7 -43.0 ;* $28 70.9 75.5 $68 31.4 33.9 $a8 4.5 5.6 $e8 -43.7 -44.9 ;* $29 69.9 74.5 $69 31.0 33.4 $a9 4.0 5.2 $e9 -45.8 -46.8 ;* $2a 69.0 73.5 $6a 30.5 32.9 $aa 3.6 4.7 $ea -47.8 -48.7 ;* $2b 68.1 72.5 $6b 30.1 32.4 $ab 3.2 4.3 $eb -49.8 -50.6 ;* $2c 67.3 71.5 $6c 29.7 31.9 $ac 2.7 3.8 $ec -51.8 -52.4 ;* $2d 66.4 70.6 $6d 29.3 31.4 $ad 2.3 3.4 $ed -53.7 -54.1 ;* $2e 65.6 69.7 $6e 28.8 30.9 $ae 1.8 2.9 $ee -55.5 -55.8 ;* $2f 64.8 68.8 $6f 28.4 30.4 $af 1.4 2.4 $ef -57.3 -57.4 ;* $30 64.0 68.0 $70 28.0 30.0 $b0 1.0 2.0 $f0 -59.0 -59.0 ;* $31 63.1 67.1 $71 27.5 29.5 $b1 0.5 1.5 $f1 -59.0 -59.0 ;* $32 62.3 66.3 $72 27.1 29.0 $b2 0.0 0.9 $f2 -59.0 -59.0 ;* $33 61.5 65.5 $73 26.6 28.6 $b3 -0.3 0.4 $f3 -59.0 -59.0 ;* $34 60.7 64.7 $74 26.2 28.1 $b4 -0.8 -0.0 $f4 -59.0 -59.0 ;* $35 59.9 63.9 $75 25.7 27.7 $b5 -1.3 -0.5 $f5 -59.0 -59.0 ;* $36 59.2 63.1 $76 25.3 27.2 $b6 -1.8 -1.1 $f6 -59.0 -59.0 ;* $37 58.4 62.3 $77 24.8 26.8 $b7 -2.3 -1.6 $f7 -59.0 -59.0 ;* $38 57.6 61.6 $78 24.4 26.4 $b8 -2.8 -2.2 $f8 -59.0 -59.0 ;* $39 56.9 60.9 $79 23.9 25.9 $b9 -3.3 -2.8 $f9 -59.0 -59.0 ;* $3a 56.1 60.1 $7a 23.5 25.5 $ba -3.8 -3.3 $fa -59.0 -59.0 ;* $3b 55.4 59.4 $7b 23.0 25.1 $bb -4.3 -3.9 $fb -59.0 -59.0 ;* $3c 54.7 58.7 $7c 22.6 24.7 $bc -4.8 -4.5 $fc -59.0 -59.0 ;* $3d 54.0 58.0 $7d 22.2 24.2 $bd -5.3 -5.1 $fd -59.0 -59.0 ;* $3e 53.3 57.3 $7e 21.8 23.8 $be -5.9 -5.7 $fe -59.0 -59.0 ;* $3f 52.6 56.6 $7f 21.4 23.4 $bf -6.4 -6.3 $ff -59.0 -59.0
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Originally Posted by jcsbanks
Engine coolant and intake air temperature
...
Above is from a DSM 1g commented disassembly from DSM-ECU Yahoo group.
...
Above is from a DSM 1g commented disassembly from DSM-ECU Yahoo group.
I fit the 1G DSM coolant temperature data between 100F and 316F to keep the polynomial down to third order. It tracks the 1G DSM data nicely between 100F and 316F:
-0.0003893xxx+0.08056xx-6.5226x+315.73
The result is in Farenheit. I deal with Centigrade all day, but still have a better feel for Farenheit. Note the syntax of the equation. This is the only way I could get EvoScan to understand it. It didn't like sci notation, it didn't like "^", and it didn't like n*x*x (x*x*x*x works though).
I fit the intake air temperature from 50F to 363F. I had to use a fifth order polynomial to get a good fit. The equation is:
-0.00000003166xxxxx+0.00001425xxxx-0.002490xxx+0.2143xx-10.279x+361.01
I did some logging in EvoScan with these long equations, and the logging rate was not adversely affected. Coolant temperature settled in a 182F which is right in line with what everyone is saying. Intake air temperature was hovering around 100F when cruising along in traffic.
Originally Posted by mrfred
Nice. My few data points match up well with with the corresponding data points in the 1G DSM data. I fooled with a bunch of curve fits, including some customized equations. The best fit for the fewest number of fitting parameters turned out to be regular old polynomial fits.
I fit the 1G DSM coolant temperature data between 100F and 316F to keep the polynomial down to third order. It tracks the 1G DSM data nicely between 100F and 316F:
-0.0003893xxx+0.08056xx-6.5226x+315.73
The result is in Farenheit. I deal with Centigrade all day, but still have a better feel for Farenheit. Note the syntax of the equation. This is the only way I could get EvoScan to understand it. It didn't like sci notation, it didn't like "^", and it didn't like n*x*x (x*x*x*x works though).
I fit the intake air temperature from 50F to 363F. I had to use a fifth order polynomial to get a good fit. The equation is:
-0.00000003166xxxxx+0.00001425xxxx-0.002490xxx+0.2143xx-10.279x+361.01
I did some logging in EvoScan with these long equations, and the logging rate was not adversely affected. Coolant temperature settled in a 182F which is right in line with what everyone is saying. Intake air temperature was hovering around 100F when cruising along in traffic.
I fit the 1G DSM coolant temperature data between 100F and 316F to keep the polynomial down to third order. It tracks the 1G DSM data nicely between 100F and 316F:
-0.0003893xxx+0.08056xx-6.5226x+315.73
The result is in Farenheit. I deal with Centigrade all day, but still have a better feel for Farenheit. Note the syntax of the equation. This is the only way I could get EvoScan to understand it. It didn't like sci notation, it didn't like "^", and it didn't like n*x*x (x*x*x*x works though).
I fit the intake air temperature from 50F to 363F. I had to use a fifth order polynomial to get a good fit. The equation is:
-0.00000003166xxxxx+0.00001425xxxx-0.002490xxx+0.2143xx-10.279x+361.01
I did some logging in EvoScan with these long equations, and the logging rate was not adversely affected. Coolant temperature settled in a 182F which is right in line with what everyone is saying. Intake air temperature was hovering around 100F when cruising along in traffic.
-1.45x + 308
for coolant temp in MMCd which I've found to be extremly accurate:
http://mmcdlogger.sourceforge.net/#Protocol
Your multiple order equations may be more accurate (I trust your math) however. In the real world that above equation has served me well for years.
Last edited by dan l; Sep 5, 2006 at 07:00 PM.
