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Heat soaked maf, giving false IATs

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Old Oct 2, 2005 | 08:51 AM
  #1  
Black02Z71's Avatar
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From: Ontario, Canada
Default Heat soaked maf, giving false IATs

At the track friday night my iat temps were 120f+ at the start of the runs, and it would drop down to around 85-95f at the end, outside temp was only 54f. The truck was running really rich, and the timing was low, I had to zero out the IAT add timing table, because it was pulling too much out.

So I am thinking of installing an iat in the egr block off plate, and see if it helps the heat soaking problem in the staging lanes. Has anybody else done this to a n/a truck, I see a lot of boosted guys doing this.
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Old Oct 2, 2005 | 12:34 PM
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From: Arizona Bay
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Are you just running the UPD intake with no modifications to it? Where is the MAF sensor located? Any pics of the setup if it is different in anyway?

I had similar experiences with my many homemade intakes and I'm just seeing if you made the same mistakes I did.
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Old Oct 2, 2005 | 09:03 PM
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The upd is unmodified, other then I have a 5" going through the bottom of the airbox down to bring air in from the fog light area. I think the maf is in a bad spot, right against the hood, so all that hot air rinses up to it.

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Old Oct 2, 2005 | 09:23 PM
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i think the sensor is reading the correct air temp. it isn't heat soaked, just reading the actual temp of the air. the sensor actualy hangs out a 1/4" or so into the air stream so the temp of the housing wont effect it's reading.
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Old Oct 2, 2005 | 11:43 PM
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Hmm....interesting. Have you tested the IAT sensor with an ohmmeter to see if the resistance is on par with the actual readings? I don't think the sensor is heat soaked by being located there. It's pretty close to the factory location. Does the clear plastic tubing heat up? Do you have access to an thermometer, preferably an infared one?
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Old Oct 3, 2005 | 01:41 PM
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The outside temp was 12C, thats about 54f, and the iat was reading 122f at the start of a run, it would only drop to the 80's by the end of the track. I just can't see that plastic tube, transfering that much heat into the air. I don't have the factory airbox holes blocked off, maybe its pulling hot air in there. I know the maf was pretty warm to the touch, what if the screen in the sensor is acting like a heating element.
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