With the recent discussion about bigger intercoolers I decided to take some data to see what our intake temps were like pre and post cac and whether the intercooler is doing its job well. I used 2 fluke 87s with thermocouples reaching inside the cac hoses and did some highway testing. These meters can display instant/min/max/avg data.
I correlated the two meters to each other and to the EVIC temp first by tying the thermocouples in the grille and driving around town. The three readings were within 2 degrees of each other at steady state, so I didn't include any offsets in these readings below. Then I inserted the probe wires into the cac hoses under the hose clamps.
Ambient temps hovered around 70F throughout the test, humidity around 50%, no A/C, rain was not a factor, elevation 5000ft. All temps reported in ºF.
I don't have boost/egt gages (yet) - that would've been great data to have. I did some testing up the same long grade at 65mph between 3rd gear w/ lockup and 5th gear w/lockup to see the temeperature difference. 3rd gear had higher post cac temps by 5-10 degrees because the higher volumetric flow rate was starting to ovewhelm the cac, but I can't say if that was achieved with lower boost or egt than in 5th gear. Other people with those gages could comment.
Code:
Steady state level cruise:
mph cac in cac out ambient
0 (N) 102 72 69
40 157 82 73
45 165 84 72
50 168 91 66
65 210 95 68
5% grade:
65 240 110 67
10% grade accelerating 30-50mph:
50 314 148 66 (point of highest recorded temps)
mph cac in cac out ambient
0 (N) 102 72 69
40 157 82 73
45 165 84 72
50 168 91 66
65 210 95 68
5% grade:
65 240 110 67
10% grade accelerating 30-50mph:
50 314 148 66 (point of highest recorded temps)
I usually run with a bug screen over the grille, but I did my testing without it for the data above. I found that adding the bug screen at the end raised post cac temps by 5-10 degrees.
The highest temps I saw were while accelerating up the 10% grade. I took the reading as the temps seemed to stabilize. A nozzle to spray water/meth across the front of the intercooler would have been interesting.
The formula for thermal efficiency of an intercooler is
E = (Tin -Tout)/(Tin-Tambient)
At 40mph cruise we are at 89%
At 65mph cruise we are at 81%.
At full load we are at 67%.
Feel free to discuss. If you have any interesting ideas for temps to measure, let me know. These probes only have a rating of about 500F, hence no EGT. I could go down the tranny dipstick tube, but others have reported trans temp before. Maybe oil temp is possible, but I don't know about putting a wire down into the oil dipstick tube!
