IAT Sensors

connorwhite.online

connorwhite.online

Active Member
Has anyone here installed an IAT sensor in their EGR delete plate or intercooler setup? There are a few options out there, but I'd love to hear about a positive experience if possible, as quality is obviously more critical here than with a post-turbo pyrometer. I can only really utilize options that have published temp/resistance curve data, as I'll have to translate that to my gauge display.
If you have installed one, let me know what your temps look like and a bit about your boost, exhaust, fuel/air setup.
 
No surprises here but yup! I have. For background I've just cross-posted my Intercooler install thread from Delica.ca here.

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K-type thermocouples, one in the inlet manifold, one in the pipe between the turbo and intercooler. Originally they were going to be temporary so I could see how well the intercooler was working, but I've left them in place. More dashboard blinkenlights = more power.

Displays are cheap Aliexpress LED temperature displays. Accuracy was tested by heating the sensors in oil up to 200C while comparing the readings to a known (very) good themometer. Both read about 2deg high, which is close enough for me.

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Results: Turbo outlet temperature is usually 50-150C (15psi max) though the sensor is about 50cm downstream of the turbo, and the air has expanded into the 2" pipes from the turbo's 1.5" outlet. I imagine temperature at the turbo is quite a bit higher, but the turbo can handle it.

With good airflow through the intercooler* inlet air temperature is usually 25-50C. When holding full boost on a slow hill IAT tops out around 60C (though this is probably more limited by exhaust temperature: by the time the inlet gets to 60C my EGT is around 1200F, so I'll ease up.)

These numbers seem surprisingly efficient for an intercooler, but I've verified the readings by swapping the sensors over: the numbers are consistent regardless of which gauge I use.

Current exhaust setup: Ceramic coated side exit, Moroso spiral flow + stainless glasspack resonator.
Boost: 15psi max unless I'm towing, then I limit it to 13psi. Controlled with an HKS EVC controller (the one with the quiet stepper motor rather than the noisy solenoid valve)
Air/Fuel: 20:1 or leaner, tuned/monitored with Innovate Motorsports MTX-L (one of the very few wideband gauges that goes leaner than 19:1). Tuned as per my FAQ post.

*(ram air from the scoop usually, though there's a fan on the intercooler that comes on if the intercooler core goes above 50C).
 
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@Growlerbearnz you fantastic human, I should've assumed! Good read on your intercooler install, thanks for including the bit about going straight out from the intake flange with the tube fitting, that'll be useful. You also did me one better with the IAT inside the manifold, I was curious if even with an intercooler, the intake manifold would be hot from the proximity of the exhaust headers. Those are crazy efficient numbers for an air-to-air, especially considering how far downwind that first IAT is. Damn, the Mazda heat exchanger is tiny but mighty! Seems the scoop was crucial. That's a much denser intake charge than I'd assumed, wow.
Growlerbearnz said:
More dashboard blinkenlights = more power.
Click to expand...
My thoughts exactly. It's my only vehicle and I'm a sucker for gauge styling so I'm taking the slow route to create an oled display. The wideband is a good call, might as well add MAP and crank sensors to setup an accessory ECU at this rate :D

Side Note:
How do you feel about the ceramic coating after some longer trips? Did you have it done professionally or cure it yourself? I coated and cured the whole intake/exhaust (2 coats primer, 3 coats base) not including anything past the down-pipe, but waited to do a new exhaust system and absolutely fried the exhaust coating (duh).

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A bit bummed, but the intake manifold is still insulated. As for the choice of white; yes I'm an unrealistic masochist, but I'm also a bit scarred after letting a few oil leaks go too long. As you can see I've forgone the exhaust cover... a mistake I'll very soon be remedying. Probably ceramic coat that too.
 
My ceramic coating is professionally installed by these guys. I've used it for years on my sportier cars because it actually keeps the heat in.

The Mini's exhaust is coated except where the parts are welded together: touch the coated pipe either side of the weld and you think "gosh, that's hot". Touch the weld and you have an instant soldering-iron type burn: crispy skin, smell of roast pork, no pain until a minute later.

In this case I decided to splash out and coat the Delica's exhaust too because I'm getting sick of repainting exhausts.

White is a very brave colour for a 4D56!
 
Growlerbearnz said:
My ceramic coating is professionally installed by these guys.
Click to expand...

Oh yes, the HiPer Coating looks much more enduring than my clay-in-a-can spray, cured in my easy-bake studio apartment oven ;)

May have to shell out on the next round. I've seen a couple spots with silica enameling treatments in the area.

So you have no chipping or flaking huh?

Growlerbearnz said:
White is a very brave colour for a 4D56!
Click to expand...

Brave is a word for it. Idealistic is another!
Truthfully the white isn't really dirty after 3000 miles. Wipes right off. But it turns an oil change to neurosurgery
 
@Growlerbearnz is oil the preferred testing medium for exposed thermistors? I've seen some try a hair dryer but that seems chaotic to find a control temp. I have to calibrate the thermistor resistance values in a Steinhardt-Hart equation because sensor manufacturers don't seem to publish datasheets :rolleyes:
 
Oil is good because it's non-conductive, will heat up above 100C, heats up evenly, and you can use a cooking thermometer to check the temperature.

...also I have a deep fryer with (calibrated) temperature display, so testing thermistors/thermocouples is super convenient. YMMV.
 
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