MI5 Persecution: Bernard Levin 1/6/96 (1556)

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. for that to happen heat would have to conduct rapidly through whatever material was used for the duct. 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. 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. 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. 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. 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. heres the thing miles the air is not pulled in it is forced into the filter by the speed of the truck. if the speed of the truck isnt in excess of 80+mph there isnt a whole heck of a lot happening. what type of truck are you talking about here very few trucks have forced air intakes. we are talking about stock trucks. exactly !! and being that they are stock the factory is not going to spend big bucks creating the best induction system possible as that both raises the cost of the truck and kills profits. they are not forced. cold air drawn in is preferable to hot air from inside the engine compartment. sure it is. but you arent going to get there by changing the tube and that is pretty much what you have done. heat is heat whether or not it is the factory tube of aftermarket once again this simply is not true. different plastics conduct heat at different levels many of these systems move the filter to a cool area many of these systems simply flow better than the factory systems. a proper duct will not conduct significant heat to the air being drawn in. you are saying that a tube heated for a hour or so in a stock truck in normal driving wont transfer the heat to the air that passes through it with zilch for velocity lol where are you getting this zilch for velocity stuff while it doesnt move as fast as a forced induction system it is not moving all that slow either and the fact that it is moving keeps the inside of the pipe cool. miles i played with forced air on drag cars years ago. true it is now old tech but pretty much the same deal.with a hood scoop and a velocity stack sealed to the scoop good for maybe 1/2 second in the 1/4. that is on a modified engine at wot. that is with cold air being stuffed dirctly into the carb through a cold 6 tall velocity stack with no filter at at all. if you managed to gain a whole half second then your gains were huge. you wont see that on a stock truck under normal use with a your tube and filter. you wont notice a mpg change that will offset money spent on the tube and filter imo. in many cased you would be correct but not for every truck or every situation. -- if at first you dont succeed youre not cut out for skydiving .