For the insulation, you might look into HVAC duct insulation since I think you could probably a foil backed insulation.

Not sure what thermocouple "type" (I'd recommend type J based on the temp range) you plan on using but just twisting the two leads tightly together to form the junction is more than sufficient.

There is an industrial insulating company about three miles from me. I don't have high hopes that they will have what I need, but, if they do, I might be able to get some free scraps. Then I'll try the HVAC place about 5 blocks away. If neither of them can help, the only other place I can think of is auto parts stores and see if they have some kind of thin, foiled exhaust blanket or header wrap with foil.

My panel meter will take J, K, & T; any of which should do the job (plus R and S, but those aren't a good choice). For what I'm doing, twisting some extension wire together would probably do the job; relative readings will be more important than absolute accuracy. I have a J or K that I use to measure temp in the garage, but it is in an industrial sheath and has a lot of lag. Will try to find a real t/c, but could strip the sheath if need be.

difference is 5.5 to 6 degres higher than the out side air temp. I have data logged it.
when driving at 100 kms. (stillen G3>)
Z

Yeah, when moving it's easy to keep close to ambient.

Mine is usually exactly the same as ambient when moving.

Got the intake air spare parts today. Everything from the radiator support to the throttle bodies.

Bought some insulation yesterday.

Took some preliminary temperature measurements last night. Six degrees difference between the VID and IAT readings! First guess is that VID is wrong.

Code:

---

Time  T/C  VID  IAT  Water
00:00  74  71  76  x
02:00  67  64  71  85
03:00  67  63  69  80
04:00  65  61  67  78
11:00  62  58  64  62

---

Stock setup. No mods made.
Had several fans blowing on radiator, air intake opening (removed filler plate between radiator support and bumper cover), and MAF area.
Unmounted ambient temp sensor and placed it and T/C together.
Car had to be started to get IAT and water temps.
T/C display was calibrated about 10 years ago, so absolute value may be off, but relative readings should be good. Will calibrate when I can find a standard.

Just curious, but what kind of insulation did you end up going with?

I checked with 3 HVAC shops and they didn't have anything. The industrial insulator didn't have time to talk. So off to the auto parts stores. All I could find was Thermo-Tech Thermo-Shield Tape and DEI Reflect-A-Cool. I have no idea how well they may insulate, but didn't have any choice. Neither seems to be particularly rugged, but should hold up long enough for my tests.

If you are looking for a recommendation, I don't know enough about either product, other than a perception of feeling "cheap" to the touch, to have an opinion. I'll post my findings as I go along.

Probably going to wrap my G3's with a material called refrasil. It's a ceramic fiber based cloth used in heat treat applications. Just hoping I have a enough scraps from work to fully wrap the intakes.

so what is the conlclusion to this test? I read a little bit when it first came out but ignored afterwards until I got my dongle in the mail for the obdII system and read it through my android. Im averaging 5-8* difference at night and about 10-15 during the day. I commute 50 miles one way and during the day time i noticed when it was 78 or so that Inlet Air Temp was up. I also noticed here that there is one owner who has g3's and has the same temp fluxuation as most of us do. So how or why is it benificial for the g3's in comparison to short ram air intakes? Please no character assasination, I might be missing out on a very valuable point but just want some clarification before I pull the trigger on modifying my intake systems. One is sucking from outside the engine bay and one from inside, but we all have collant lines running through the throttle body so that does warm up the air before going into the plenum. So clarification would be greatly appreciated.

No conclusions, yet. I'm waiting for a friend's daughter to insulate the spare air ducts I bought, but school and boys are slowing her down.

I would think that pulling cooler air from outside the engine compartment would be better.

From what I have read, yes, the TB coolant lines will warm up the air. If I can figure out a good way to measure the air temperature after the TB, I will collect that data also.

you could drill a hole in the top of the intake and use a expoxy to seal up the whole if you use a thermocouple. Which brings the question of where is the intake air temp being read at? I thought it was the maf but I may be wrong. I don't disagree when it comes to pulling air outside, but here is my stumbling block. We as a customer are spending 150bucks on 3 degrees of air for 3 or 4 hp (gen3, aem, injen, etc) compared to a k&n or takeda? Most of the times cruising down the hwy the difference would be an avg of 5 or 6* right? if you are stuck in traffic then they both seem to have the same heat soak.

Also some useful information, the other night I took the wife out on date night in the z. When we left the resturante from dinner my intake air temp was around 130 from being parked for dinner. After some city driving (ambient temp was 44) it dropped down to about 95. When I got on the hwy it plummeted in a matter of 20-45 seconds to 46.

I'd like to find a less permanent/destructive way to do it. There are several vacuum lines that I may be able to tee into (t/c through the run and current hose on the branch).
I still haven't found a good (ie, cheap) solution for taking 4-5 temperature readings at the same time. I have found a dual-channel t/c meter that I will be ordering this week or next, but at $9 I'm afraid that it will not be very be accurate. If it does turn out to be reasonably accurate, I'll order more.

The ECU uses the MAF temperature on bank 1 for IAT.

I'm trying to see what can be done to the stock setup. I'm not worried so much about an increase in HP, but rather keeping IAT below where the ECU starts pulling timing (which I suppose is, in effect, a boost in HP).
If the insulation works well enough, I won't need to spend money on a CAI. :)

I've noticed much the same. Takes forever to get temps back to normal at city speeds after a long stop.
Did coolant temp go way up, also? Was the big drop at the same time that coolant temp dropped? The TB coolant loop may be having a larger effect on IAT than I suspect.

I am not suggesting the hp gain merely the effect of the three degrees of differing temp. I suspect the same with the tb coolant lines but nissan tech stated it was for cooling the air prior to entering the plenum. My radiator does cool rather fast but ambient temp was 44 and had almost no traffic at night.. During warmer weather it is true for temps to take longer to drop, havent had my reader during summer or warm weather but am anxious for the results. However when it was 80* out on my way to work heat soak was apparent in a matter of 2 mins.

Also if it is reading from maf then thats not a accuate readi g due to the fact that there is a heat source at the tb. In my opinion this is a faulty design.

I gave up on getting my friend's daughter to insulate the intake ducts and started doing it myself. It's slow work and it ain't pretty. The insulation is not very thick, but the silvered cover should reflect a lot of heat. Will post some pics later this week.

getting a woman to do a mans job most of the time is a fail lol. I was able to purchase some gen3's. But still in it for the results. I think the most common problem is air flow. But we shall see. Good luck with the results!