MI5 Persecution: David Hepworth (1) 26/2/97 (10117)

From : Annonymous

Q: roy wrote if you are talking about today by the time the cold air travels through the filter and through the hot tube to the tb it is no longer cold that simply isnt true at all. really yea really. what does the tube cool it no it shields it from the heat in the engine compartment which is the reason its there to begin with. for that to happen heat would have to conduct rapidly through whatever material was used for the duct. it is already hot from the air that it surrounds it. the tube may be hot on the outside but since they dont conduct heat very well they are cooler on the inside. you would be correct for some of the cheaper thin walled plastic that could conduct heat. however the better styles are double walled or made of thicker materials that dont conduct heat all that well. the air is traveling through the duct much too fast to heat up appreciably. let me try again. the material that the tube is made from is going to aquire the same temp. that the rest of the engine does or darn close to it. if you are talking about the outside of the tube then you are probably correct. im talking about the air in the engine compartment under the hood where the tube is surrounded by air which is well over 120 degrees. then you are correct as that is also the temp on the ouside of the tube. that heat will transfer through the walls of the tube so that the inner wall that the air is passing through is also the same temp. now this is where you are wrong. heat transfer thru some plastics is very inefficient and that is a desired trait for air tube being used to funnel cold air thru a hot engine compartment. wtf is this thing part of the space shuttle gif the tube is under the hood for a hour at at normal operating temp are you trying to tell me the inside of the tube is cool yep because cool air if flowing thru it and is taking away the small amount of heat that the pipe is conducting from the outside. now you introduce air that has already been slowed by the hot filter and then has to proceed through the tube to the tb. again you are making invalid assumptions. in most of these kits the filter is on the beginning of the duct and usually near a point of cold air entry and shielded from the engine heat which makes it the coolest part of the system. and at the filter the air is slowed down. the air filter doesnt slow it down all that much. the engine is an air pump and has to have a certian amount of air to run. we have had this discussion many times with based around k&n filters. even if the air is slowed down by the filter as you say the filter is at the same temp as the incomming air so no heat is added by it. seeing as it isnt a forced air induction there isnt a heck of a lot of velocity moving it. what makes you believe that this air is moving so fast that it wont pick up heat from whatever it travels through it is not a matter of the air picking up heat it is a matter of how much. okay for the sake of this mindnumbing exercise lets say it is 80 degrees outside you have been rideing around for 45 minutes with a/c on driving at 35-45 mph the engine compartment is well over 120 degrees what would you figure the air temp is when this 80 degree air upon entery to the filter is when it hits the tb for the time it will be in the tube less than a second i would say that it might get to around 82 and that would be way to the high side. the air will pick up a bunch of heat as it passes through the filter and tube. thus the gain in performance or mpg compared to factory is going to be nil imo. you are making assumptions that are not always true. in many cases the filter is not hot and the air will not pick up much heat there. the plastics that many of these better induction systems are made out of do not conduct heat well which minimises heat transfer to the air inside of them. then you can add the fact that many of these systems flow better than the factory system and the air filter is less restrictive which leads to increased air flow and even less heat transfer. tom your talking nothing but bs here. it is a stock truck with stock tb stock cam stock putor all stock. the less restiction means nada to it. as does this so called cold air. if it was a race car modified to handle a fater mix then everything matters. but it isnt. now the one talking bs is you. what does stock have to do with anything it is still an engine just the same and more cooler air translates into more hp. that stock puter as you call it does monitor both air flow and temp and when it sees more cooler air it responds to it. we are not talking 100 hp gains and in some vehicles the gains may be so small as to be non-existant but you cannot say that about every stock truck. stock is what this whole thing was about. as you say the gains may