And not to argue but your opinions are wrong, and theorys are wrong. If you were right all Bosch ECU setups or other mfgs cars would have been running that setup for a long time. Intake manifold temps affect air temps highly. It was why on the 2.0t they went to a plastic manifold instead of aluminum in order to control heat transfer.
My theories are right, but my application of those theories might not fit this scenario the best. Also Bosch, VAG, and every other manufacturer are not infaliable. Just look at Toyota. Up until recently they were known for their reliability and safety. Now look at them. There are plenty of design flaws in everyday products that don't really matter that much because it just works, and manufacturers aren't going to spend the money to fix them just to make them work "perfectly" unless they absolutely have to.
Intake manifold temperatures do affect air charge temperatures, but not as much as how an aluminum manifold will affect the IAT sensor. There's a reason why everything from electronics to automotive applications use aluminum. It transfers heat well, especially to things it comes into contact with. Here's a good example of where I'm coming from: blow across a red-hot hot plate. The air coming off the other side is warm, but it won't give you 3rd degree burns like the plate does. If you have something that can mimic the amount of air an engine moves blow across the hot plate you probably won't notice much of a difference in air temps leaving the plate as the air temps entering. If you wanted the air temperature to change you'd have to increase the surface area it is being blown across, or slow down the air speed so it stays around long enough to absorb some of the heat. Now if you were to mount an air temperature sensor to the hot plate it would be heated by the hot plate. So, unless there is a damn good insulator packed into that tiny little sensor, the air traveling over the sensor has to cool the heat generated from the sensor as well as the heat radiating up through the sensor. Therefore the readings aren't perfect, but either the "errors" are compensated for by the computer or the readings are not as critical as it appears. So exactly why, other than "that's how Bosch does it", does the sensor have to be in the manifold? I still think it's better to mount it in something that will insulate it from potential heat transfer (plastic bushing, plastic manifold, something metal that isn't directly bolted to metal parts that generate heat like a head or around heat generating parts, etc.) than getting it as close to the cylinder inlet(s) as possible. I just don't see your reasoning's on why it's so critical to place it there for anything other than when the engine is idleing.
So Jeff, in the attempt of trying not to thread jack you, here's a good debate by two parties with different thoughts on the subject with support for their ideas on the best place and the things to consider for the placement of your intake air temperature sensor. for your car.
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Topic: 16v ABA stuff (Read 486 times)