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GTOholic
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Discussion Starter #1
During my data collection run last night, I recorded my IAT and it NEVER went below 109*F and got as high as 132*F. These are the numbers while the car was MOVING. My "Cold Air Intake" is anything BUT a "Cold Air Intake".

So... what to do? Go back to the stock box? Is my IAT sensor faulty? Any suggestions?
 

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Captain Thread Killer returns
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FLORIT said:
During my data collection run last night, I recorded my IAT and it NEVER went below 109*F and got as high as 132*F. These are the numbers while the car was MOVING. My "Cold Air Intake" is anything BUT a "Cold Air Intake".

So... what to do? Go back to the stock box? Is my IAT sensor faulty? Any suggestions?

Well what are the so called "normal temps"
I mean what is it with the stock box.....How do you know that is too high?
 

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GTOholic
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Discussion Starter #3
It is my understanding that the Intake Air Temperature should be near the ambient (outside) air temperature. Last night was a comfortable "high 70's" evening, so I would not expect the IAT to be 30-60*F above that. I am going to put the stock air box back on when I get home and repeat the datalogging.
 

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Knight Errant
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Let us know

FLORIT said:
It is my understanding that the Intake Air Temperature should be near the ambient (outside) air temperature. Last night was a comfortable "high 70's" evening, so I would not expect the IAT to be 30-60*F above that. I am going to put the stock air box back on when I get home and repeat the datalogging.
I think I might have an idea if the differential is way wide...
 

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May I quote you on that?
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MY IAT's with a stock box are a few degrees above ambient with the car moving, after any heat soak has dissipated. A cold car, with the ignition on, should read ambient, discounting any heating from the sun. If that's way off, your IAT sensor is probably bad, otherwise you're sucking hot air. No insult intended. An isolation box shouldn't be too hard to fabricate, using the original, possibly enlarged, cold air inlet per 1CoolPC.
 

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FLORIT said:
During my data collection run last night, I recorded my IAT and it NEVER went below 109*F and got as high as 132*F. These are the numbers while the car was MOVING. My "Cold Air Intake" is anything BUT a "Cold Air Intake".

So... what to do? Go back to the stock box? Is my IAT sensor faulty? Any suggestions?

I was worried about this when I installed mine. I that I was told that once I was moving it would be okay but this shows it's not. Isn't it worse having the high temps than having low temps with some air restriction (stock box)???
 

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GTOholic
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Discussion Starter #7
I installed the stock air box and did two data runs; one in "city driving" with mild acceleration, and one on the highway doing between 60 and 70. NOTE: I did not start scanning until the engine was hot. It had been idling for at least five minutes. Here is a quick summary of my data:

Speed Inc. HFI
Avg ECT = 201.58*F, Avg IAT = 120.82*F, a difference of 80.76*F
Avg MAF = 3.69 lb/min
Avg MAP = 4.61 psi

Stock Box (City)
Avg ECT = 218.23*F, Avg IAT = 111.15*F, a difference of 107.08*F
Avg MAF = 2.58 lb/min
Avg MAP = 4.71 psi

Stock Box (Highway)
Avg ECT = 200.36*F, Avg IAT = 101.32*F, a difference of 99.04*F
Avg MAF = 4.39 lb/min
Avg MAP = 5.12 psi
 

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Go Tigers!
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Was the Speed Inc. intake numbers at highway? Man, I ain't touching my stock
box, at least until the aftermarket products shake out a little.
 

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We NEED to feed these GOATS COLD AIR! I can't believe so many people bought the warm air intakes. Its not the pipe and the filter that provide the gains, its the COLD air! On my current daily driver my air filter almost drags on the road, just to suck up the ice cold air.
 

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GTOholic
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Discussion Starter #10
In fairness to the Speed Inc. HFI kit, I need to re-collect data with the kit installed. I did not follow the same procedure for both the HFI and the stock box.

Also, using HP Tuner to examine my PCM Power Enrich tables, I found that IAT does not add anything to the Fuel Multiplier. In other words, the fuel injectors do not respond to changes in Intake Air Temperature.

The general concensus is that "more air" and "colder air" generate "more power." What I want to determine is whether the change in Manifold Air Pressure provided by the HFI is offset by the change in Intake Air Temperature. According to the tables, the IAT is insignificant to fuel control.

I always thought "rich" meant more fuel and "lean" meant more air, but from reading in this forum and the HP Tuner forum, it seems I have that reversed. Would someone please clarify this?
 

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I did some generic testing on my Predator and I came up with this.

About 60* outside the IAT was about 90* sitting still and about 80* moving doing about 45 MPH.

I would need someone else to watch the tuner and recording the readings.

We need to find some cold air for our cars.
 

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Rocket said:
We NEED to feed these GOATS COLD AIR! I can't believe so many people bought the warm air intakes. Its not the pipe and the filter that provide the gains, its the COLD air! On my current daily driver my air filter almost drags on the road, just to suck up the ice cold air.

At idle, you should be close to ambient assuming you are not just-starting a black car in Arizona that has been parked from 8AM-3PM on a hot August day. Keep in mind, once your car is moving over a certain speed (6-8 MPH+/-) you are truly pulling ambient air. The air traveling through your intake system is moving so fast, that it does not have time to heat up from contact with any heat-soaked intake components. However, there are pressure factors that come into play that can affect the air intake charge. Larger filtration companies (K&N) use a Computational Flow Dynamics Program to find the best combination of temperature and pressure under the hood for their intake system filter placement. Generally speaking, 10 degrees-F is equal to @ 1HP, and 1.5-lbs of pressure is equal to another @ 1HP. But again, oncd a vehicle is moving, the air temp is ambient.

If you spend some time searching teh web, you can find some interesting white papers on air flow temperature cause & effect cases. But then again, if you look long enough, you can probably find some cases against the same claims... IMHO
 

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Somebody help. We have two threads on this subject and the coclusions are different. The other thread is "Why a new intake". Most of you people have been on that thread also.

Does the CAI suck in hot air while driving or not?!?
 

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GTOholic
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Discussion Starter #15
Well, the bottom line for me is that my IAT is nowhere NEAR ambient. Either my sensor is malfunctioning or the air is getting heated by SOMETHING. This is one of those things that will bug the daylights out of me until I find the explanation. And it is probably no big deal at all.
 

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Extreme said:
Has anyone tried MPD CAI box w/wo ram air?

I would like to see a pic of it? I dont think they even have one on the site.
 

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There are two issues here. One is where the air is drawn from, and the second is the concept of heat soak. They really are separate. By that I mean that a true CAI on a black car on a hot day, just idling, will read higher intake temps than the same CAI cruising down the road. I know perhaps you are saying "duh" to yourself, but, I just wanted to make that clear.

If you are drawing from under the hood, you will NEVER reach ambient. Pop the hood and actually study how cool air could possibly get through the grill and into the engine bay. It's NO straight shot! I have participated in much testing and discussion on this topic with my current car club and the fact is that the underhood area is somewhat of a pocket at any speed.

Cold air is more important than any pressure increase you can attain with an intake! If we were talking about forced induction, that's a different story, but any ram-air type effect is miniscule compared to the gains you get from the air being cold and dense.

You want an intake that draws the coldest air possible, period. Either from very low in the engine bay (could suck water, you need to be careful) or from the top of the wheel well through the fender. Is there room for this type of layout on the goat? It could be the cleanest.

Brian
 

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FLORIT- Can you get one of those digital thermometers that has a probe? You could stick the probe within your intake and secure the display with zip ties to a windshield wiper arm or perhaps even bring it inside through the window if the wires long enough.
 
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