The temperature should be measured as close to the cylinder as possible. I don't think there ever was a debate over that. The issue is that this causes heat soak in some cases which would prompt people to move it before the TB which is where the debate lies (at least that's my take on it).Philip Lochner wrote:All my logic tells me that it should be so. I remember seeing so many debates, as to whether the MAT sensor should be before or after the TB - and those are just the ones I did see - let alone the ones I did not see. Are we perhaps now arriving, with good reason, at the conclusion that the MAT sensor SHOULD be after the TB (thereby taking into account not only the temp before the TB but also the pressure drop over the TB and its resulting cooling/density effect) ?jsmcortina wrote:If the temp sensor is supposed to be installed in the manifold, wouldn't that temp drop already be allowed for?
The problem here is that table seems to attribute all of the pressure difference to temperature difference. I don't think that's correct. The lower pressure is due to volume variation from the piston "sucking" the air. The equation is: P1V1/T1 = P2V2/T2Philip Lochner wrote:Now a new dilemma. I'm driving along at WOT with 100kpa (ie at sea level) and 50degC (122F) MAT (before and after the TB) and suddenly I lift my foot and MAP goes to 40kpa. IF the table I presented above is anywhere close, the inlet air temp after the TB at this new condition should very suddenly move to -74degC (-101F) - too fast for even an open element sensor to register besides being out of range most likely. This is distorting my brain... I MUST be missing something here...
so while there is probably a temperature variation, I'm sure it's far from what you show in the table above. Otherwise you'd see everyone suffering from TB icing at any ambient temperature.
Jean