So I recently had an MS parallel built for one of my 94's by Chad (cjernigan). Awesome build quality and ******* amazing tech support over the phone. He called me more than my girlfriend over the weekend to see how it was coming and if i figured **** out. He even walked out of a wedding to call me, not his. Anyway, back to the matter at hand, easytherm values. Seems for some reason nobody had these available for the 94-early95 Miata, at least not the Bias Resistance settings. So I did a ton of trial and error testing, swapping my PNP and MS parallel in and out of the car while holding sensors in ice, seeing when fan cames on, etc. What I finally settled on was close enough. MT indicated 212 clt when fans came on, i think the factory ecu turns them on at 205. so its off my ~3% which i can deal with for now. MT showed iat temps of ~35-36 in a cup of ice water, again, close enough for now. With the following settings, the temps mimicked what my MSPNP showed when i quickly swapped setups. I'll probably work on it a lil more but I lent my MS out to some idiot that totally screwed up his build(compy) so it'll have to wait till I get it back. Here are the settings I settled on. The CLT temp-resistance pairs are DIY's values. The IAT values are GM sensor defaults. I know it shouldn't make sense that the IAT resistor value is lower than R4 in the MS but i'm sharing the sensor with the stock ECU so i'm sharing the stock bias resistor as well so the bias had to be adjusted. Copy at your own risk.

__________________

How often DOES he call your girlfriend?

why low the bias? if the factory bias is 1.4K, then you need to add 2.4K in there for R7 and R4. so 3915 total each.

well there is no r7 but 3915 for the IAT didn't work out

question on easytherm. is it possible that the easytherm program takes into account that you are using a 2490ohm resister at R4 and nothing at R7 so there is no need to add 2490 to the IAT value? anyone? i mean it is designed for the MS, right?
has anyone who has added the 2490 value to IAT actually tested their numbers by holding the sensor in a known temperature liquid while still connected to the car harness and read the temp values in MT?

cuz i did. i held the GM IAT sensor in a thermos of 191 degree water(according to a thermometer i used) and MT showed 191 exactly. and i know the thermometer was accurate because it showed ~212 in a pot of boiling water.

__________________

do this. click on rx7 defaults, and click write. it will prompt you to add 2490.

no. it will not.

it'll do this

Attached Thumbnails

 

last time it prompted me to change it to 49490. dunno why yours is different.


btw, i love how you took the screenshot after you posted



here;'s the thing, when you generate the file, it will say file generated with 47000 bias on R4.


; Generated using EasyTherm4.exe,
;
; Air Temp Thermistor Comment Field
;
; ***** CAUTION - NON STD BIAS RESISTOR REQUIRED *****
; File generated for use with 47000 ohm resistor at R4

maybe an upgrade that takes into account the 2490 in the MS? lets try this, write yours with stock rx7 settings and lets compare my matfactor.inc with yours

; Generated using EasyTherm4.exe,
;
; Air Temp Thermistor Comment Field
;
; ***** CAUTION - NON STD BIAS RESISTOR REQUIRED *****
; File generated for use with 47000 ohm resistor at R4
;
; Steinhart-Hart coefficients: A= 8.591697E-04 B=2.323741E-04 C= 6.746512E-08
;
; Input Data Temp, degC Resistance
; 20 41500
; 50 11850
; 85 3500
;

MATFACTOR:
; ADC Temp, degF
DB 100T ; 0 Sensor Failure - 100% applied
DB 255T ; 1 404.93
DB 255T ; 2 340.95
DB 255T ; 3 307.43
DB 255T ; 4 285.13
DB 255T ; 5 268.60
DB 255T ; 6 255.54
DB 255T ; 7 244.80
DB 255T ; 8 235.70
DB 255T ; 9 227.82
DB 255T ; 10 220.89
DB 255T ; 11 214.70
DB 249T ; 12 209.12
DB 244T ; 13 204.05
DB 239T ; 14 199.39
DB 235T ; 15 195.09
DB 231T ; 16 191.10
DB 227T ; 17 187.37
DB 224T ; 18 183.88
DB 221T ; 19 180.60
DB 218T ; 20 177.50
DB 215T ; 21 174.57
DB 212T ; 22 171.78
DB 209T ; 23 169.13
DB 207T ; 24 166.59
DB 204T ; 25 164.17
DB 202T ; 26 161.85
DB 200T ; 27 159.62
DB 197T ; 28 157.48
DB 195T ; 29 155.42
DB 193T ; 30 153.43
DB 192T ; 31 151.51
DB 190T ; 32 149.65
DB 188T ; 33 147.85
DB 186T ; 34 146.10
DB 184T ; 35 144.41
DB 183T ; 36 142.77
DB 181T ; 37 141.17
DB 180T ; 38 139.61
DB 178T ; 39 138.10
DB 177T ; 40 136.62
DB 175T ; 41 135.18
DB 174T ; 42 133.77
DB 172T ; 43 132.40
DB 171T ; 44 131.05
DB 170T ; 45 129.74
DB 168T ; 46 128.45
DB 167T ; 47 127.19
DB 166T ; 48 125.96
DB 165T ; 49 124.75
DB 164T ; 50 123.56
DB 162T ; 51 122.40
DB 161T ; 52 121.26
DB 160T ; 53 120.13
DB 159T ; 54 119.03
DB 158T ; 55 117.94
DB 157T ; 56 116.87
DB 156T ; 57 115.82
DB 155T ; 58 114.79
DB 154T ; 59 113.77
DB 153T ; 60 112.77
DB 152T ; 61 111.78
DB 151T ; 62 110.81
DB 150T ; 63 109.85
DB 149T ; 64 108.90
DB 148T ; 65 107.96
DB 147T ; 66 107.04
DB 146T ; 67 106.13
DB 145T ; 68 105.23
DB 144T ; 69 104.34
DB 143T ; 70 103.46
DB 143T ; 71 102.59
DB 142T ; 72 101.73
DB 141T ; 73 100.88
DB 140T ; 74 100.04
DB 139T ; 75 99.21
DB 138T ; 76 98.39
DB 138T ; 77 97.58
DB 137T ; 78 96.77
DB 136T ; 79 95.97
DB 135T ; 80 95.18
DB 134T ; 81 94.40
DB 134T ; 82 93.62
DB 133T ; 83 92.86
DB 132T ; 84 92.09
DB 131T ; 85 91.34
DB 131T ; 86 90.59
DB 130T ; 87 89.84
DB 129T ; 88 89.11
DB 128T ; 89 88.37
DB 128T ; 90 87.65
DB 127T ; 91 86.93
DB 126T ; 92 86.21
DB 126T ; 93 85.50
DB 125T ; 94 84.80
DB 124T ; 95 84.09
DB 123T ; 96 83.40
DB 123T ; 97 82.71
DB 122T ; 98 82.02
DB 121T ; 99 81.33
DB 121T ; 100 80.65
DB 120T ; 101 79.98
DB 119T ; 102 79.31
DB 119T ; 103 78.64
DB 118T ; 104 77.97
DB 117T ; 105 77.31
DB 117T ; 106 76.66
DB 116T ; 107 76.00
DB 115T ; 108 75.35
DB 115T ; 109 74.70
DB 114T ; 110 74.05
DB 113T ; 111 73.41
DB 113T ; 112 72.77
DB 112T ; 113 72.13
DB 111T ; 114 71.50
DB 111T ; 115 70.87
DB 110T ; 116 70.24
DB 110T ; 117 69.61
DB 109T ; 118 68.98
DB 108T ; 119 68.36
DB 108T ; 120 67.74
DB 107T ; 121 67.12
DB 106T ; 122 66.50
DB 106T ; 123 65.88
DB 105T ; 124 65.27
DB 105T ; 125 64.65
DB 104T ; 126 64.04
DB 103T ; 127 63.43
DB 103T ; 128 62.82
DB 102T ; 129 62.21
DB 102T ; 130 61.61
DB 101T ; 131 61.00
DB 100T ; 132 60.40
DB 100T ; 133 59.79
DB 99T ; 134 59.19
DB 99T ; 135 58.59
DB 98T ; 136 57.98
DB 97T ; 137 57.38
DB 97T ; 138 56.78
DB 96T ; 139 56.18
DB 96T ; 140 55.58
DB 95T ; 141 54.98
DB 94T ; 142 54.38
DB 94T ; 143 53.79
DB 93T ; 144 53.19
DB 93T ; 145 52.59
DB 92T ; 146 51.99
DB 91T ; 147 51.39
DB 91T ; 148 50.79
DB 90T ; 149 50.19
DB 90T ; 150 49.59
DB 89T ; 151 48.99
DB 88T ; 152 48.39
DB 88T ; 153 47.79
DB 87T ; 154 47.18
DB 87T ; 155 46.58
DB 86T ; 156 45.98
DB 85T ; 157 45.37
DB 85T ; 158 44.76
DB 84T ; 159 44.16
DB 84T ; 160 43.55
DB 83T ; 161 42.94
DB 82T ; 162 42.33
DB 82T ; 163 41.71
DB 81T ; 164 41.10
DB 80T ; 165 40.48
DB 80T ; 166 39.87
DB 79T ; 167 39.25
DB 79T ; 168 38.63
DB 78T ; 169 38.00
DB 77T ; 170 37.38
DB 77T ; 171 36.75
DB 76T ; 172 36.12
DB 75T ; 173 35.48
DB 75T ; 174 34.85
DB 74T ; 175 34.21
DB 74T ; 176 33.57
DB 73T ; 177 32.92
DB 72T ; 178 32.27
DB 72T ; 179 31.62
DB 71T ; 180 30.97
DB 70T ; 181 30.31
DB 70T ; 182 29.65
DB 69T ; 183 28.98
DB 68T ; 184 28.31
DB 68T ; 185 27.64
DB 67T ; 186 26.96
DB 66T ; 187 26.28
DB 66T ; 188 25.59
DB 65T ; 189 24.90
DB 64T ; 190 24.20
DB 63T ; 191 23.50
DB 63T ; 192 22.79
DB 62T ; 193 22.08
DB 61T ; 194 21.36
DB 61T ; 195 20.63
DB 60T ; 196 19.90
DB 59T ; 197 19.16
DB 58T ; 198 18.41
DB 58T ; 199 17.66
DB 57T ; 200 16.89
DB 56T ; 201 16.13
DB 55T ; 202 15.35
DB 55T ; 203 14.56
DB 54T ; 204 13.77
DB 53T ; 205 12.96
DB 52T ; 206 12.15
DB 51T ; 207 11.32
DB 50T ; 208 10.48
DB 50T ; 209 9.64
DB 49T ; 210 8.78
DB 48T ; 211 7.91
DB 47T ; 212 7.02
DB 46T ; 213 6.12
DB 45T ; 214 5.21
DB 44T ; 215 4.28
DB 43T ; 216 3.34
DB 42T ; 217 2.38
DB 41T ; 218 1.40
DB 40T ; 219 .41
DB 39T ; 220 -.61
DB 38T ; 221 -1.64
DB 37T ; 222 -2.70
DB 36T ; 223 -3.78
DB 35T ; 224 -4.89
DB 34T ; 225 -6.02
DB 33T ; 226 -7.18
DB 32T ; 227 -8.37
DB 30T ; 228 -9.60
DB 29T ; 229 -10.85
DB 28T ; 230 -12.15
DB 27T ; 231 -13.48
DB 25T ; 232 -14.86
DB 24T ; 233 -16.29
DB 22T ; 234 -17.77
DB 21T ; 235 -19.30
DB 19T ; 236 -20.90
DB 17T ; 237 -22.57
DB 16T ; 238 -24.31
DB 14T ; 239 -26.14
DB 12T ; 240 -28.06
DB 10T ; 241 -30.09
DB 8T ; 242 -32.25
DB 5T ; 243 -34.54
DB 3T ; 244 -37.01
DB 0T ; 245 -39.67
DB 0T ; 246 -42.57
DB 0T ; 247 -45.76
DB 0T ; 248 -49.31
DB 0T ; 249 -53.33
DB 0T ; 250 -57.98
DB 0T ; 251 -63.53
DB 0T ; 252 -70.48
DB 0T ; 253 -79.91
DB 0T ; 254 -95.13
DB 100T ; 255 Sensor Failure - 100% applied

__________________

U.S. taxpayers have spent $15 trillion on so-called anti-poverty

programs—a figure slightly less than the national debt.

; Generated using EasyTherm4.exe,
;
; Air Temp Thermistor Comment Field
;
; ***** CAUTION - NON STD BIAS RESISTOR REQUIRED *****
; File generated for use with 47000 ohm resistor at R4
;
; Steinhart-Hart coefficients: A= 8.591697E-04 B=2.323741E-04 C= 6.746512E-08
;
; Input Data Temp, degC Resistance
; 20 41500
; 50 11850
; 85 3500
;

MATFACTOR:
; ADC Temp, degF
DB 100T ; 0 Sensor Failure - 100% applied
DB 255T ; 1 404.93
DB 255T ; 2 340.95
DB 255T ; 3 307.43
DB 255T ; 4 285.13
DB 255T ; 5 268.60
DB 255T ; 6 255.54
DB 255T ; 7 244.80
DB 255T ; 8 235.70
DB 255T ; 9 227.82
DB 255T ; 10 220.89
DB 255T ; 11 214.70
DB 249T ; 12 209.12
DB 244T ; 13 204.05
DB 239T ; 14 199.39
DB 235T ; 15 195.09
DB 231T ; 16 191.10
DB 227T ; 17 187.37
DB 224T ; 18 183.88
DB 221T ; 19 180.60
DB 218T ; 20 177.50
DB 215T ; 21 174.57
DB 212T ; 22 171.78
DB 209T ; 23 169.13
DB 207T ; 24 166.59
DB 204T ; 25 164.17
DB 202T ; 26 161.85
DB 200T ; 27 159.62
DB 197T ; 28 157.48
DB 195T ; 29 155.42
DB 193T ; 30 153.43
DB 192T ; 31 151.51
DB 190T ; 32 149.65
DB 188T ; 33 147.85
DB 186T ; 34 146.10
DB 184T ; 35 144.41
DB 183T ; 36 142.77
DB 181T ; 37 141.17
DB 180T ; 38 139.61
DB 178T ; 39 138.10
DB 177T ; 40 136.62
DB 175T ; 41 135.18
DB 174T ; 42 133.77
DB 172T ; 43 132.40
DB 171T ; 44 131.05
DB 170T ; 45 129.74
DB 168T ; 46 128.45
DB 167T ; 47 127.19
DB 166T ; 48 125.96
DB 165T ; 49 124.75
DB 164T ; 50 123.56
DB 162T ; 51 122.40
DB 161T ; 52 121.26
DB 160T ; 53 120.13
DB 159T ; 54 119.03
DB 158T ; 55 117.94
DB 157T ; 56 116.87
DB 156T ; 57 115.82
DB 155T ; 58 114.79
DB 154T ; 59 113.77
DB 153T ; 60 112.77
DB 152T ; 61 111.78
DB 151T ; 62 110.81
DB 150T ; 63 109.85
DB 149T ; 64 108.90
DB 148T ; 65 107.96
DB 147T ; 66 107.04
DB 146T ; 67 106.13
DB 145T ; 68 105.23
DB 144T ; 69 104.34
DB 143T ; 70 103.46
DB 143T ; 71 102.59
DB 142T ; 72 101.73
DB 141T ; 73 100.88
DB 140T ; 74 100.04
DB 139T ; 75 99.21
DB 138T ; 76 98.39
DB 138T ; 77 97.58
DB 137T ; 78 96.77
DB 136T ; 79 95.97
DB 135T ; 80 95.18
DB 134T ; 81 94.40
DB 134T ; 82 93.62
DB 133T ; 83 92.86
DB 132T ; 84 92.09
DB 131T ; 85 91.34
DB 131T ; 86 90.59
DB 130T ; 87 89.84
DB 129T ; 88 89.11
DB 128T ; 89 88.37
DB 128T ; 90 87.65
DB 127T ; 91 86.93
DB 126T ; 92 86.21
DB 126T ; 93 85.50
DB 125T ; 94 84.80
DB 124T ; 95 84.09
DB 123T ; 96 83.40
DB 123T ; 97 82.71
DB 122T ; 98 82.02
DB 121T ; 99 81.33
DB 121T ; 100 80.65
DB 120T ; 101 79.98
DB 119T ; 102 79.31
DB 119T ; 103 78.64
DB 118T ; 104 77.97
DB 117T ; 105 77.31
DB 117T ; 106 76.66
DB 116T ; 107 76.00
DB 115T ; 108 75.35
DB 115T ; 109 74.70
DB 114T ; 110 74.05
DB 113T ; 111 73.41
DB 113T ; 112 72.77
DB 112T ; 113 72.13
DB 111T ; 114 71.50
DB 111T ; 115 70.87
DB 110T ; 116 70.24
DB 110T ; 117 69.61
DB 109T ; 118 68.98
DB 108T ; 119 68.36
DB 108T ; 120 67.74
DB 107T ; 121 67.12
DB 106T ; 122 66.50
DB 106T ; 123 65.88
DB 105T ; 124 65.27
DB 105T ; 125 64.65
DB 104T ; 126 64.04
DB 103T ; 127 63.43
DB 103T ; 128 62.82
DB 102T ; 129 62.21
DB 102T ; 130 61.61
DB 101T ; 131 61.00
DB 100T ; 132 60.40
DB 100T ; 133 59.79
DB 99T ; 134 59.19
DB 99T ; 135 58.59
DB 98T ; 136 57.98
DB 97T ; 137 57.38
DB 97T ; 138 56.78
DB 96T ; 139 56.18
DB 96T ; 140 55.58
DB 95T ; 141 54.98
DB 94T ; 142 54.38
DB 94T ; 143 53.79
DB 93T ; 144 53.19
DB 93T ; 145 52.59
DB 92T ; 146 51.99
DB 91T ; 147 51.39
DB 91T ; 148 50.79
DB 90T ; 149 50.19
DB 90T ; 150 49.59
DB 89T ; 151 48.99
DB 88T ; 152 48.39
DB 88T ; 153 47.79
DB 87T ; 154 47.18
DB 87T ; 155 46.58
DB 86T ; 156 45.98
DB 85T ; 157 45.37
DB 85T ; 158 44.76
DB 84T ; 159 44.16
DB 84T ; 160 43.55
DB 83T ; 161 42.94
DB 82T ; 162 42.33
DB 82T ; 163 41.71
DB 81T ; 164 41.10
DB 80T ; 165 40.48
DB 80T ; 166 39.87
DB 79T ; 167 39.25
DB 79T ; 168 38.63
DB 78T ; 169 38.00
DB 77T ; 170 37.38
DB 77T ; 171 36.75
DB 76T ; 172 36.12
DB 75T ; 173 35.48
DB 75T ; 174 34.85
DB 74T ; 175 34.21
DB 74T ; 176 33.57
DB 73T ; 177 32.92
DB 72T ; 178 32.27
DB 72T ; 179 31.62
DB 71T ; 180 30.97
DB 70T ; 181 30.31
DB 70T ; 182 29.65
DB 69T ; 183 28.98
DB 68T ; 184 28.31
DB 68T ; 185 27.64
DB 67T ; 186 26.96
DB 66T ; 187 26.28
DB 66T ; 188 25.59
DB 65T ; 189 24.90
DB 64T ; 190 24.20
DB 63T ; 191 23.50
DB 63T ; 192 22.79
DB 62T ; 193 22.08
DB 61T ; 194 21.36
DB 61T ; 195 20.63
DB 60T ; 196 19.90
DB 59T ; 197 19.16
DB 58T ; 198 18.41
DB 58T ; 199 17.66
DB 57T ; 200 16.89
DB 56T ; 201 16.13
DB 55T ; 202 15.35
DB 55T ; 203 14.56
DB 54T ; 204 13.77
DB 53T ; 205 12.96
DB 52T ; 206 12.15
DB 51T ; 207 11.32
DB 50T ; 208 10.48
DB 50T ; 209 9.64
DB 49T ; 210 8.78
DB 48T ; 211 7.91
DB 47T ; 212 7.02
DB 46T ; 213 6.12
DB 45T ; 214 5.21
DB 44T ; 215 4.28
DB 43T ; 216 3.34
DB 42T ; 217 2.38
DB 41T ; 218 1.40
DB 40T ; 219 .41
DB 39T ; 220 -.61
DB 38T ; 221 -1.64
DB 37T ; 222 -2.70
DB 36T ; 223 -3.78
DB 35T ; 224 -4.89
DB 34T ; 225 -6.02
DB 33T ; 226 -7.18
DB 32T ; 227 -8.37
DB 30T ; 228 -9.60
DB 29T ; 229 -10.85
DB 28T ; 230 -12.15
DB 27T ; 231 -13.48
DB 25T ; 232 -14.86
DB 24T ; 233 -16.29
DB 22T ; 234 -17.77
DB 21T ; 235 -19.30
DB 19T ; 236 -20.90
DB 17T ; 237 -22.57
DB 16T ; 238 -24.31
DB 14T ; 239 -26.14
DB 12T ; 240 -28.06
DB 10T ; 241 -30.09
DB 8T ; 242 -32.25
DB 5T ; 243 -34.54
DB 3T ; 244 -37.01
DB 0T ; 245 -39.67
DB 0T ; 246 -42.57
DB 0T ; 247 -45.76
DB 0T ; 248 -49.31
DB 0T ; 249 -53.33
DB 0T ; 250 -57.98
DB 0T ; 251 -63.53
DB 0T ; 252 -70.48
DB 0T ; 253 -79.91
DB 0T ; 254 -95.13
DB 100T ; 255 Sensor Failure - 100% applied

__________________

look the same

yeah dunno what to tell you. either the resistance values are wrong or the bias is wrong. id assume the values diy is using are good, so its the bias that's the killer. can you measure the resistance at the MAF connector with the MS in place?

so have you tested your IAT sensor in ice water and very hot water that you know the temp of? god i hope that gm sensor is waterproof

so stick multimeter in pins 2&3(from right) on MAF plug while car is on and stock ecu and ms are connected?

no i can't, i lent my MS out.

well, either way you know the MS has a 2.4K resistor in it, so if you can measure the resitance of the ECU bias, add the two, you should be golden.


or if someone had factory shop manual for a 94-95......

i do....2

it doesnt list the values? it should, somewhere in there.

for the sensors yes, still looking for any info on ECU

So that would explain that easy therm does not compensate for what it thinks may be the bias resistors in your megasquirt.

I am still curious why you decided to change the bias resistance on the AIT, how many times did you reflash your ECU to determine that that bias resistance gave you the most accurate value?