IAT/MAT (Intak/Manifold Air Temp) Sensor

Fuel Supply & Ignition Systems

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kangaboy
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IAT/MAT (Intak/Manifold Air Temp) Sensor

Post by kangaboy » Mon Jun 13, 2016 8:53 am

Hey all,
I have my manifold off the car right now and figured since I didn't put a temp sensor on, maybe now would be a good time. So I have been doing a bit of reading, and don't know which sensor would be more beneficial. IAT or MAT. Here is a discussion that I was reading up on regarding the IAT and where to put it (before the TB but after an intercooler). I was leaning towards the MAT sensor after the TB, but after reading this, I don't know anymore. I am also assuming both sensors are actually the same, and the only difference in the name is where they are located along the system (before or after the TB).

http://www.miataturbo.net/megasquirt-18 ... ion-30372/

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Chip Birks
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Re: IAT/MAT (Intak/Manifold Air Temp) Sensor

Post by Chip Birks » Mon Jun 13, 2016 11:06 am

I'd put it in the place that measures the temp of the air actually entering the combustion chamber. Meaning post intercooler, post water meth, etc...

mads b (dk)
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Re: IAT/MAT (Intak/Manifold Air Temp) Sensor

Post by mads b (dk) » Mon Jun 13, 2016 11:32 am

It impossible to tune ve map probably without it.... been there

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kangaboy
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Re: IAT/MAT (Intak/Manifold Air Temp) Sensor

Post by kangaboy » Mon Jun 13, 2016 11:39 am

Chip Birks wrote:I'd put it in the place that measures the temp of the air actually entering the combustion chamber. Meaning post intercooler, post water meth, etc...
Post throttle body as well? I was gonna put it in my cross pipe on my "T" manifold.

Clonebug
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Re: IAT/MAT (Intak/Manifold Air Temp) Sensor

Post by Clonebug » Mon Jun 13, 2016 8:50 pm

I have mine just after the Tee.

Image
Stripped66 wrote:The point wasn't to argue air temps with the current world record holder, but to dispel the claim that the K03 is wrapped up at 150 HP. It's not.

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Chip Birks
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Re: IAT/MAT (Intak/Manifold Air Temp) Sensor

Post by Chip Birks » Tue Jun 14, 2016 8:34 am

kangaboy wrote:
Chip Birks wrote:I'd put it in the place that measures the temp of the air actually entering the combustion chamber. Meaning post intercooler, post water meth, etc...
Post throttle body as well? I was gonna put it in my cross pipe on my "T" manifold.
Mine is in my plenum, right above the head. Way past the TB.

jhoefer
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Re: IAT/MAT (Intak/Manifold Air Temp) Sensor

Post by jhoefer » Fri Jun 24, 2016 6:46 pm

For you to correctly calculate air density, you want the MAT sensor to be reading the exact same air as the MAP sensor. So ideally both should be located in the intake manifold and at roughly the same location.

Putting a MAT sensor before an intercooler is wrong because of the obvious air temp difference between the inlet and outlet of the intercooler. Same for water/meth injectors. Putting the sensor before the throttle isn't really correct either because the pressure drop through it is going to change the air temp in the manifold and screw up the density calculation. Also, the further up the intake tract you get from the throttle allows for more time for the air to heat up and distort the calculation a bit. You can make it work putting it before the throttle obviously, you just end up tuning around the discrepancies.

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