Quote:
Originally Posted by spuggy
930 has a bigger fan than the 3.0, I believe? My high CHTs when idling were recorded in high ambients; as relatively ineffective as my heat exchangers are at 14F, the flappers would most certainly be closed at 80+F...
All of my datum has been harvested in cold/cool ambients. 34*F-65*F
IDK about the size of the fan. I do know that there are different pulley ratios for different submodels of 911.
I've always set the idle to 1050 when hot. It seems much happier there with SC cams.
Yeah, I want to get the idle down to 900. It'll take me a little bit to figure out how the IACV programming works on top of getting the warmup strategy dialed in.
You're welcome!
That does seem odd.
Perhaps double-check the calibration for the sensor? Despite both being NTC thermistors, the Magneti Marelli and Bosch sensors have very different curves. To the point that I deemed them non-interchangeable (and markedly so <100C) when trying to avoid a 400% markup over the generic...
I do intend to confirm the calibration curves for all the sensors.
I believe all Bosch NTC sensors are the same composition/provide the same curve, certainly all the ones I've compared the datasheets for are.. I'd also strongly suspect the 993 sensor would be Bosch 
As Jonny suggested, some thermal paste between the fins/sensor - and maybe a few drops of oil/AT fluid in the housing - to improve thermal connectivity? |
I need to make a new CHT sensor adapter. There's a pinhole in the bottom of the adapter, so any fluid will run out and all over the engine. That tiny cavity of air could be affecting my readings, but I doubt by too much. **But I'm not that kind of doctor, so it's entirely possible I've underestimated the effect of that small air gap.
Kelly is going out tonight, so I plan to spend some quality time in the garage when I get home from work. I'm going to pull the breather cover, drill & tap it, install the sensor, and pull the CHT sensor & adapter. I'll see if Ethan can buzz closed the tiny pinhole in it tomorrow. I'll have to make some decisions about whether or not to make any wiring changes.