Mazda Air Temp Sensor - Big Handicap for Tuning and Optimum Performance?
09-02-03, 03:37 PM
#1
Mazda Air Temp Sensor - Big Handicap for Tuning and Optimum Performance?
Here are some samples off a datalogit logging run.
The people that know Datalogit will recognize the headings, though I moddified them slightly for readability.
My system injects water at 5psi and above, 5psi = 35 bst or .35bar.
This analysis tells me the Mazda air temp sensor gets heat soaked and has a very slow reaction time to the actual air temp being sucked in by the motor.
To me this sucks. How can you tune a car when the sensor measures an abnormally high air intake temp and the actual air into the motor is a lot cooler.
Then after the colder air is already been consumed the sensor measure abnormally cooler air intake when it actually is a lot hotter.
You can tell by the log that it takes a long time for the sensor to measure the cool air intake. At that point it is too late.
Jeez, I wonder why it is so difficult to tune these motors well without blowing them up. No wonder tuners take the safe route and tune very rich. Sometimes the ecu is thinking the air is hot and it's really cooler and sometimes it says it's cool and it's really hotter.
For this first run notice the sensor says its at 54C at start of water injected at 88 seconds. Water in injected for 8 seconds and the probe drops it only 6C. It is probably closer to 25C cooler. Then after water is done the probe continues to measure dropped temps for 6 seconds to 43C or 5C drop, when the temps being injected are back to being much higher.
You can see the same thing in the other 4 logging examples.
Time----Inj---IL IT Rpm Kh Bst K Wt-Air-Bat
88.117 46.5 20 6 4953 85 53 1 87 54 13.6
88.838 46.5 11 -3 4734 89 103 1 87 54 13.5
90.010 53.9 13 -1 5277 101 119 1 87 52 13.5
91.001 45.2 12 0 3920 108 40 1 87 51 13.6
92.013 45.7 13 -1 4116 113 70 6 87 51 13.6
93.004 46.0 13 -1 4347 119 105 7 87 50 13.5
94.015 46.0 13 -1 4578 126 110 1 87 49 13.6
95.007 46.4 16 2 4807 133 94 25 88 48 13.6
96.018 31.7 42 42 4844 137 -399 1 88 48 13.6
97.000 25.7 42 42 4719 136 -450 1 88 47 13.6
98.011 20.7 43 43 4664 134 -518 1 88 46 13.8
99.013 19.7 42 42 4548 131 -527 1 89 45 13.6
100.004 19.2 42 42 4458 129 -525 1 89 45 13.6
101.006 19.7 42 42 4401 126 -512 1 89 44 13.6
102.037 19.7 41 41 4322 124 -508 1 89 43 13.6
Time----Inj---IL IT Rpm Kh Bst K Wt-Air-Bat
144.568 45.7 17 4 4340 86 50 5 91 42 13.6
145.740 47.4 14 0 4943 95 108 5 91 41 13.6
148.013 45.0 14 0 3826 105 59 7 91 39 13.6
149.015 45.2 15 1 4051 111 78 13 91 38 13.6
150.016 45.7 16 2 4261 118 67 1 91 38 13.6
151.017 0.0 40 40 4157 119 -629 1 91 37 13.6
153.000 0.0 36 36 3807 112 -651 1 91 36 13.6
155.013 0.0 33 33 3245 97 -647 1 91 35 13.6
156.015 0.0 32 32 2928 88 -642 1 91 34 13.8
Time----Inj---IL IT Rpm Kh Bst K Wt-Air-Bat
185.026 45.7 16 2 4225 116 62 1 91 34 13.6
186.028 29.8 37 37 4211 119 -340 1 91 33 13.6
188.001 23.0 38 38 4107 117 -444 1 91 33 13.6
189.002 22.1 38 38 4054 116 -456 1 91 32 13.8
190.044 21.7 36 36 3993 114 -457 1 91 31 13.6
192.026 22.0 36 36 3930 112 -445 1 91 30 13.8
194.009 21.6 36 36 3883 111 -446 1 91 29 13.8
196.012 21.6 35 35 3834 109 -445 1 91 28 13.6
Time----Inj---IL IT Rpm Kh Bst K Wt-Air-Bat
214.018 45.7 16 2 4173 115 64 1 91 27 13.6
215.029 46.0 15 1 4440 121 87 11 91 27 13.6
217.012 46.5 22 13 4832 134 17 1 91 27 13.8
221.018 35.0 45 45 5281 152 -418 1 91 27 13.6
227.027 22.7 44 44 4807 138 -508 1 91 26 13.8
229.000 22.7 43 43 4678 134 -498 2 91 25 13.6
231.002 0.0 42 42 4501 130 -662 2 92 24 13.8
232.034 0.0 41 41 4290 126 -664 1 92 24 13.8
233.045 0.0 39 39 4062 119 -659 1 92 23 13.6
Time----Inj---IL IT Rpm Kh Bst K Wt-Air-Bat
130.016 46.2 16 3 4327 85 56 3 95 49 13.3
131.018 46.5 22 14 4643 91 10 1 95 49 13.5
132.120 52.7 12 -2 5222 100 118 20 95 49 13.3
133.001 61.0 13 -1 5764 109 117 1 95 49 13.5
134.002 48.5 26 16 6014 118 22 1 95 48 13.3
135.004 0.0 49 49 5957 122 -578 1 95 47 13.6
136.005 0.0 48 48 5773 120 -631 1 95 46 13.6
137.017 0.0 47 47 5597 116 -684 1 95 46 13.5
138.018 0.0 47 47 5419 113 -655 1 95 45 13.6
139.019 0.0 47 47 5248 109 -680 1 95 44 13.6
140.001 0.0 46 46 5074 106 -685 1 95 44 13.6
141.002 28.3 45 45 5016 103 -451 16 95 43 13.6
142.014 43.4 40 40 5033 103 -300 1 95 43 13.5
144.027 37.2 43 43 5133 104 -379 1 95 42 13.5
The people that know Datalogit will recognize the headings, though I moddified them slightly for readability.
My system injects water at 5psi and above, 5psi = 35 bst or .35bar.
This analysis tells me the Mazda air temp sensor gets heat soaked and has a very slow reaction time to the actual air temp being sucked in by the motor.
To me this sucks. How can you tune a car when the sensor measures an abnormally high air intake temp and the actual air into the motor is a lot cooler.
Then after the colder air is already been consumed the sensor measure abnormally cooler air intake when it actually is a lot hotter.
You can tell by the log that it takes a long time for the sensor to measure the cool air intake. At that point it is too late.
Jeez, I wonder why it is so difficult to tune these motors well without blowing them up. No wonder tuners take the safe route and tune very rich. Sometimes the ecu is thinking the air is hot and it's really cooler and sometimes it says it's cool and it's really hotter.
For this first run notice the sensor says its at 54C at start of water injected at 88 seconds. Water in injected for 8 seconds and the probe drops it only 6C. It is probably closer to 25C cooler. Then after water is done the probe continues to measure dropped temps for 6 seconds to 43C or 5C drop, when the temps being injected are back to being much higher.
You can see the same thing in the other 4 logging examples.
Time----Inj---IL IT Rpm Kh Bst K Wt-Air-Bat
88.117 46.5 20 6 4953 85 53 1 87 54 13.6
88.838 46.5 11 -3 4734 89 103 1 87 54 13.5
90.010 53.9 13 -1 5277 101 119 1 87 52 13.5
91.001 45.2 12 0 3920 108 40 1 87 51 13.6
92.013 45.7 13 -1 4116 113 70 6 87 51 13.6
93.004 46.0 13 -1 4347 119 105 7 87 50 13.5
94.015 46.0 13 -1 4578 126 110 1 87 49 13.6
95.007 46.4 16 2 4807 133 94 25 88 48 13.6
96.018 31.7 42 42 4844 137 -399 1 88 48 13.6
97.000 25.7 42 42 4719 136 -450 1 88 47 13.6
98.011 20.7 43 43 4664 134 -518 1 88 46 13.8
99.013 19.7 42 42 4548 131 -527 1 89 45 13.6
100.004 19.2 42 42 4458 129 -525 1 89 45 13.6
101.006 19.7 42 42 4401 126 -512 1 89 44 13.6
102.037 19.7 41 41 4322 124 -508 1 89 43 13.6
Time----Inj---IL IT Rpm Kh Bst K Wt-Air-Bat
144.568 45.7 17 4 4340 86 50 5 91 42 13.6
145.740 47.4 14 0 4943 95 108 5 91 41 13.6
148.013 45.0 14 0 3826 105 59 7 91 39 13.6
149.015 45.2 15 1 4051 111 78 13 91 38 13.6
150.016 45.7 16 2 4261 118 67 1 91 38 13.6
151.017 0.0 40 40 4157 119 -629 1 91 37 13.6
153.000 0.0 36 36 3807 112 -651 1 91 36 13.6
155.013 0.0 33 33 3245 97 -647 1 91 35 13.6
156.015 0.0 32 32 2928 88 -642 1 91 34 13.8
Time----Inj---IL IT Rpm Kh Bst K Wt-Air-Bat
185.026 45.7 16 2 4225 116 62 1 91 34 13.6
186.028 29.8 37 37 4211 119 -340 1 91 33 13.6
188.001 23.0 38 38 4107 117 -444 1 91 33 13.6
189.002 22.1 38 38 4054 116 -456 1 91 32 13.8
190.044 21.7 36 36 3993 114 -457 1 91 31 13.6
192.026 22.0 36 36 3930 112 -445 1 91 30 13.8
194.009 21.6 36 36 3883 111 -446 1 91 29 13.8
196.012 21.6 35 35 3834 109 -445 1 91 28 13.6
Time----Inj---IL IT Rpm Kh Bst K Wt-Air-Bat
214.018 45.7 16 2 4173 115 64 1 91 27 13.6
215.029 46.0 15 1 4440 121 87 11 91 27 13.6
217.012 46.5 22 13 4832 134 17 1 91 27 13.8
221.018 35.0 45 45 5281 152 -418 1 91 27 13.6
227.027 22.7 44 44 4807 138 -508 1 91 26 13.8
229.000 22.7 43 43 4678 134 -498 2 91 25 13.6
231.002 0.0 42 42 4501 130 -662 2 92 24 13.8
232.034 0.0 41 41 4290 126 -664 1 92 24 13.8
233.045 0.0 39 39 4062 119 -659 1 92 23 13.6
Time----Inj---IL IT Rpm Kh Bst K Wt-Air-Bat
130.016 46.2 16 3 4327 85 56 3 95 49 13.3
131.018 46.5 22 14 4643 91 10 1 95 49 13.5
132.120 52.7 12 -2 5222 100 118 20 95 49 13.3
133.001 61.0 13 -1 5764 109 117 1 95 49 13.5
134.002 48.5 26 16 6014 118 22 1 95 48 13.3
135.004 0.0 49 49 5957 122 -578 1 95 47 13.6
136.005 0.0 48 48 5773 120 -631 1 95 46 13.6
137.017 0.0 47 47 5597 116 -684 1 95 46 13.5
138.018 0.0 47 47 5419 113 -655 1 95 45 13.6
139.019 0.0 47 47 5248 109 -680 1 95 44 13.6
140.001 0.0 46 46 5074 106 -685 1 95 44 13.6
141.002 28.3 45 45 5016 103 -451 16 95 43 13.6
142.014 43.4 40 40 5033 103 -300 1 95 43 13.5
144.027 37.2 43 43 5133 104 -379 1 95 42 13.5
09-02-03, 04:20 PM
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