After reviewing the temperature measurements from the last drive home I decided that I wanted to move the airbox temperature sensor probe from the pre-filter side of the airbox to the post-filter side.
I set about making this move when I hit a snag, while attaching a 7mm socket to the end of a wrench the socket fell, down between the radiator carrier and the engine. It bounced off one part and then the dreaded silence, indicating that it had not fallen through to the garage floor.
Peering down between the spaces I could not spot the socket, and as the photo above indicates, I had to try a bit more to see if I could find the stray tool. Unfortunately even with the front end in the service position I could not find the socket nor bounce it free from wherever it landed. I wasn’t going to drain the coolant to pull the whole front of the car off so I resigned myself to settling to use a 9/32″ socket instead until it either the 7mm falls out in the garage, or I purchase a replacement 7mm socket.
I continued on with what I had come out to the garage to do 90 minutes earlier, repositioning the air temperature sensor to the post-air filter side of the airbox.
The airbox was reassembled and positioned back where it regularly sits. This sensor will work in conjunction with the sensor shown below.
This afternoon I recorded the commute temperatures. Although the car had sat for seven and a half hours since a morning drive the temperature inside the pre-turbo inlet pipe was about 10 degrees F higher than the temperature inside the airbox.
Shortly after starting the engine the IAT inside the intake manifold dropped down to around the temperature inside the pre-turbo inlet pipe, but only for a brief time. In the past I have found that the compressor wheel is a significant source of heating for the intake air even when the car is out of boost.
Not surprisingly the air temperature inside the airbox fluctuates rapidly under stop and go conditions with a warming engine compartment. Note that I also have done the Darintake mod to the lower half of my airbox thereby allowing more air from the engine compartment to enter the airbox.
During the path from the airbox to the sensor in the pre-turbo inlet pipe the air is heated about 10 degF.
I have some thermal foil (aka Reflect-a-gold) on hand that I intended to try out on some of the intake components to see what effect it has.
Of course Aluminum foil is another option that I might include in the mix.
The rapid fluctuations of the airbox temperature have me reconsidering the placement of the temperature probe inside the airbox. The probe tip is on the pre-filter side of the box, I’m thinking that perhaps the temperature swing will be slower on the post-filter side, and possible a little warmer, which would be something that I would prefer to record, so that if applying gold-silver-aluminum sheets to the airbox did cool the airbox it may be more noticeable on the post-filter side.
Figuring out how to get the probe on that side while ensuring the filter can still do its job is the next puzzle to solve.