what are your air intake temps? Options

[match220]

Hey guys,
Since I have a Gen III in my st204 w/o a GTFour body kit I've been watching my intake temps carefully. (Autronic brand IAT is mounted as close to the engine as I can get it without it being directly above the engine). When I first finished building the engine for the car I still had the insulation on the hood and had a semi covered enclosure for the air filter. The hottest my air intake would get was 80C (crazy!) and that was sitting in traffic with no airflow over my I/C (front mount). Then driving it was around 65C. At night driving it would go down to 60C.

After pondering what to do and talking with some drifting friends, I ended up raising up the rear of my hood 4mm, which isn't even noticeable, removing the weather stripping. And also removing the insulation from the hood and making a full enclosure around the airfilter out of plastic and Plexiglas . NOW my air temps are 60C on a hot day sitting in traffic with no air flow over the I/C, and 45C moving on the freeway on a hot day. At night on the freeway it is 40C.

relevant intake info(shortened from above): big fmic (air/air), and Autronic brand IAT mounted two feet from TB inlet, not directly above engine. Numbers below are before and after a full air filter enclosure and raised rear of hood 4mm.

-------------------------Before-------After
hot day in traffic------80C---------60C
hot day on hwy-------65C---------45C
night on hwy----------60C---------40C

(80c is 176f, 65c is 149f, 60c is 140f, 45c is 113f, 40c is 104f)

So now that I've mentioned my numbers, I would like to know what your numbers are. I'm expecting it to be cooler once I get the hood vents. I would like to know what the norm is for this engine. Also please mention if you have the fmic or tmic

This post has been edited by match220: Aug 3, 2013 - 5:13 PM

[lagos]

You should pretty much ignore any intake air temps at idle or slow traffic. Thats not really the true air temperature, its just the air temp sensor getting heat soaked.

In my car I see temps around 10-15F higher than ambient temp. So if its 80F out, Ill have an AIT of about 95. The highest I have seen was 150F, and thats after turning the car off on a hot day and letting it sit for 10 mins. Once I fire the car up and idle it for 3min, the temps drop right back down. This is with a 29x9x6 front mount IC.

Even though most of those extreme temps are just heatsoak, it IS a good idea to fix the problem, as the ECU is programmed to retard a fair bit of ignition timing when the AITs rise.