just move the iat sensor! for permanent cold air!
#11
#12
I did some reading on the IAT a little while back.. It's funny, because it is really hard to find out precisely what it does and when it does it.. it does have bearing on a/f, but it's difficult to determine how much..
let's say it does dump fuel because it thinks the air is cooler (or maybe even because the air is cooler).. what good does that do you? A richer engine doesn't produce as much gitty-up as a lean engine.. it's only dumping fuel because cooler/denser air is tougher to ignite than warmer/less dense air...
One thing for certain the IAT WILL do if it isn't reading somewhat correctly: it will throw at you a p1281.. Engine too cool for too long.. And you will chase your tail trying to figure out what is wrong with your cooling system until you stumble across that, and most likely by accident..
and another thing about the IAT that surprised me: they may or may not be sending good information as it is.. the parameters they work in are pretty broad is my guess.. if you unhook it you should get an instant code- but that doesn't mean the sensor is in optimum condition, it just means the PCM knows it's plugged in..
as far as having it moved from the manifold- I have mine in the air-hat because of the FI.. I don't think it's harming a thing there- and because the o2's have the final say in a/f ratio.. but that doesn't mean the PCM is tickled about conflicting information either.
let's say it does dump fuel because it thinks the air is cooler (or maybe even because the air is cooler).. what good does that do you? A richer engine doesn't produce as much gitty-up as a lean engine.. it's only dumping fuel because cooler/denser air is tougher to ignite than warmer/less dense air...
One thing for certain the IAT WILL do if it isn't reading somewhat correctly: it will throw at you a p1281.. Engine too cool for too long.. And you will chase your tail trying to figure out what is wrong with your cooling system until you stumble across that, and most likely by accident..
and another thing about the IAT that surprised me: they may or may not be sending good information as it is.. the parameters they work in are pretty broad is my guess.. if you unhook it you should get an instant code- but that doesn't mean the sensor is in optimum condition, it just means the PCM knows it's plugged in..
as far as having it moved from the manifold- I have mine in the air-hat because of the FI.. I don't think it's harming a thing there- and because the o2's have the final say in a/f ratio.. but that doesn't mean the PCM is tickled about conflicting information either.
#13
Interesting info here. When i got my sct from hemi he advised me to put the iat sensor in my intake tube. Something to do with it getting the true and correct air temps and it gets heatsoaked in the manifold. He alsp said something about with lower temps from the iat the pcm pulls less timing then with hotter readings and the extra fuel is min.
#14
which is most likely why the OP got some ping above 4k and with the iat in the hat.. the air was warmer than the PCM thought and it didn't pull timing- hence the pre-detonation.. if the air was denser and cooler, it would be more difficult to ignite and the PCM knows this, so it allows the timing to stay advanced.. if it were to know the truth, and pulled timing, he wouldn't have gotten those pre-dets..
#17
#18
Drew is missing one small but critical fact: the O2 feedback system is NOT in closed loop under acceleration. Instead the system is operating on pre-mapped fuel injection levels based on input from TPS, IAT, MAP, engine temp, RPM, knock sensors, etc. In fact, it's normally in closed-loop ONLY at less than 20% throttle or 60% RPM. If it could run in closed-loop all the time there would be no need for some of those other sensors. The ONLY time power is limited due to hot temps the system IS IN OPEN-LOOP, because your foot is on the floor.
These pre-mapped open-loop injection levels are the only things changed in performance ECU tuning - the stoichiometric ratio imposed during closed-loop operation doesn't change regardless of programming.
What happens when the IAT sensor is installed in the intake manifold near the heads, is that the sensor, along with the aluminum intake, gets heat soaked, heated by hot metal radiating and conducting all around it, especially when driving slow or idling on a hot day. This means the sensor itself becomes higher temp than the incoming air... especially after a second of WOT when all the air downstream of the air filter is replaced with fresh air, the air to sensor temp difference can be extreme - fast moving incoming air will not be in the intake system long enough to get hot. The result of this false reading is the open-loop mapped mixture will lean out the fuel, making the engine burn hotter, magnifying the problem until it returns to closed-loop operation.
So... putting the IAT in the intake will reduce this exaggerated reading during open loop, the mixture will enrich closer to where it SHOULD be, which is BETTER for your engine, and you'll get MORE POWER, as the computer will know the air is not as hot as it thought it was when it was screwed into that big heat-sink on top of your engine.
Inside a K&N tube (or your stock intake tube) is the best place to put it because it will give the most accurate air temp reading, and will read hotter when the air it's breathing really is hotter.
Do NOT cheat the system by putting a fixed or variable resistor inline because the output will not be representative of real temp variation, your fuel consumption will suffer unnecessarily, you will foul your O2 sensors, and burn up your catalytic converter. And do NOT put your sensor in front of your radiator either, because that's not the air temp you engine sees either.
But, for all you guys that pulled your IATs out of your FIPK because you were convinced by Drew, put 'em back! Your truck will thank you, and repay you with better acceleration.
These pre-mapped open-loop injection levels are the only things changed in performance ECU tuning - the stoichiometric ratio imposed during closed-loop operation doesn't change regardless of programming.
What happens when the IAT sensor is installed in the intake manifold near the heads, is that the sensor, along with the aluminum intake, gets heat soaked, heated by hot metal radiating and conducting all around it, especially when driving slow or idling on a hot day. This means the sensor itself becomes higher temp than the incoming air... especially after a second of WOT when all the air downstream of the air filter is replaced with fresh air, the air to sensor temp difference can be extreme - fast moving incoming air will not be in the intake system long enough to get hot. The result of this false reading is the open-loop mapped mixture will lean out the fuel, making the engine burn hotter, magnifying the problem until it returns to closed-loop operation.
So... putting the IAT in the intake will reduce this exaggerated reading during open loop, the mixture will enrich closer to where it SHOULD be, which is BETTER for your engine, and you'll get MORE POWER, as the computer will know the air is not as hot as it thought it was when it was screwed into that big heat-sink on top of your engine.
Inside a K&N tube (or your stock intake tube) is the best place to put it because it will give the most accurate air temp reading, and will read hotter when the air it's breathing really is hotter.
Do NOT cheat the system by putting a fixed or variable resistor inline because the output will not be representative of real temp variation, your fuel consumption will suffer unnecessarily, you will foul your O2 sensors, and burn up your catalytic converter. And do NOT put your sensor in front of your radiator either, because that's not the air temp you engine sees either.
But, for all you guys that pulled your IATs out of your FIPK because you were convinced by Drew, put 'em back! Your truck will thank you, and repay you with better acceleration.
#20
And along that line ....You guys going to an open element filter without a functional hood scoop...Mistake, big mistake.
Keep the K&N or stock with the IAT in the tube and be happy.
Dodge really did do a good job on the intake side of the 5.9 Magnum, where they blew it is on the exhaust side because Green Weenies are everywhere.
Keep the K&N or stock with the IAT in the tube and be happy.
Dodge really did do a good job on the intake side of the 5.9 Magnum, where they blew it is on the exhaust side because Green Weenies are everywhere.