Brandnew
Structural
- Mar 5, 2002
- 41
I'm having an argument about the proper location of the intake air temp (IAT) sensor with a fellow car fan. I'm sure I'm right but I want to check with you guys to make me feel better (or worse?).
Okay, the car in question has an IAT sensor right at the throttle body. The throttle body on this car is attached right to the intake manifold. Okay, that works fine.
Now, as I've posted previously, there is a kit that allows us to put a Roots supercharger on a new custom intake manifold. Here's the problem. The kit does NOT relocate the IAT sensor. With the SC kit the IAT sensor is left on the throttle body and thus never reads the "SC heated" intake air temperature.
First off, this is bad right?? A lot of the people are having LTFT issues and I think that this sensor location could be (at least part of) the cause. Probable or not??
Second, I'm recommended moving the location of the IAT sensor to the intake manifold. They state that this isn't really necessary since you won't gain anything since the LTFT compensates for it. They also state that putting the IAT sensor in the intake manifold will create more problems becasue the sensor will "heatsoak" from the IM heat and cause false high intake readings.
---I think the IAT sensor is there for a reason; to provide as accurate inputs as possible. Why have it if the ECU has to compensate for it??
---I have another car with the IAT sensor in the intake manifold with no problems so I don't agree with them. What is everyones take on IM mounting of IAT sensors?? Is "heatsoak" a concern or not??
On a slightly related note, there is a discussion that the "tuner" has compensated for this improper mounting location and temperture reading. People are saying that the tuner adds "X" amount of heat to the reading to get the fuel calculations correct. The problem is the "tuner" doesn't measure boost so the can't know when the SC is actually increasing the air temperature.
--Can the ECU even be programmed to do this (it's a newer Motronic system)??? People are saying that this is "probably" done by matrix based tables to modify the temperature. I don't think you can use the ECU maps to modify an input, can you?
I personally don't think the tuner has done anything to the tmperautures. I think they just let the ECU compensate at it's whim (i.e. O2 sensors).
Bascially, I think the kit needs a lot of work to be properly impletmented to this car. Just checking if my way of thinking is correct.
Sorry for the long post. Thanks in advance!!
Okay, the car in question has an IAT sensor right at the throttle body. The throttle body on this car is attached right to the intake manifold. Okay, that works fine.
Now, as I've posted previously, there is a kit that allows us to put a Roots supercharger on a new custom intake manifold. Here's the problem. The kit does NOT relocate the IAT sensor. With the SC kit the IAT sensor is left on the throttle body and thus never reads the "SC heated" intake air temperature.
First off, this is bad right?? A lot of the people are having LTFT issues and I think that this sensor location could be (at least part of) the cause. Probable or not??
Second, I'm recommended moving the location of the IAT sensor to the intake manifold. They state that this isn't really necessary since you won't gain anything since the LTFT compensates for it. They also state that putting the IAT sensor in the intake manifold will create more problems becasue the sensor will "heatsoak" from the IM heat and cause false high intake readings.
---I think the IAT sensor is there for a reason; to provide as accurate inputs as possible. Why have it if the ECU has to compensate for it??
---I have another car with the IAT sensor in the intake manifold with no problems so I don't agree with them. What is everyones take on IM mounting of IAT sensors?? Is "heatsoak" a concern or not??
On a slightly related note, there is a discussion that the "tuner" has compensated for this improper mounting location and temperture reading. People are saying that the tuner adds "X" amount of heat to the reading to get the fuel calculations correct. The problem is the "tuner" doesn't measure boost so the can't know when the SC is actually increasing the air temperature.
--Can the ECU even be programmed to do this (it's a newer Motronic system)??? People are saying that this is "probably" done by matrix based tables to modify the temperature. I don't think you can use the ECU maps to modify an input, can you?
I personally don't think the tuner has done anything to the tmperautures. I think they just let the ECU compensate at it's whim (i.e. O2 sensors).
Bascially, I think the kit needs a lot of work to be properly impletmented to this car. Just checking if my way of thinking is correct.
Sorry for the long post. Thanks in advance!!
