Ive wondered the same thing. If you have a big enough turbo and used the shortest possable charge pipe from the turbo to the throttle body. Notmal system w/a turbo puts an intercooler in between thoe turbo and throttle body because when the charge of air goes up from outside air into the turbo it gets heated above ambiant temp. So, it, (intercooler) brings the temp at the point it enters the engine back to a temp as cool as possable because cool air is dense air

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But I've thought about the fact that 1) when the "packet(s)" of air go through the bends of a charge pipe and the passages inside the intercooler, it gets slowed down and thus the pressure at point of entering the engine is slightly redused. 2) the charge pipes get hot too, equal too the ambient temp of the engine compartment. That adds more temp to the air going to the intercooler so it has to start with air heated by said pipes and tubo. The air spends way less time in the turbo so the heat increase if you do the math, a lot of the added heat comes from the charge pipes themselves to the intercooler & from intercooler to throttle body. The piping can get sort of heat soaked.
3) The bends and shape of piping changes to meet engine compartment size slows the air and puts piping close to hot parts. The channeling inside most intercoolers slows the air charge some.
SOOO... Why not use a super short charge pipe straight from turbo to throttle body...no intercooler at all. You do away with all that piping, do away with all the air resistance... Would the little heat loss you get from an intercooler and the power you get from that...Has it been tested against the same engine but the 2nd one would have as a direct a path to the throttle body as possible... The pressure would be better. Much less lag. The air, even when traveling via a square or round tube,nit will stay as tight to the center and away from the walls as it can. Its taking the path of least resistance. They measure the intake temp from the cylinder head, rt where the air goes in the engine at the intake manifold. Its so close to the cylinder head that its gonna show a much higher temp then the air actually is at its center in the columns of air going down each runner. If you give the air charge as a direct enough path, I theorize, that in the right set up, you would come out ahead. Especially if you used h20-meth injection in your system... multiport h20/meth with a new intake manifold and its already set to use inhectors and has its own fuel rail and is water cooled as well. A piggy back runs the system. This is on a direct injection engine Iike found in an Audi or VW. It helps carbon build up a whole lot too. I generally really like the idea of h20-meth w/multiport injection at the cylinder head and intake manifold just like a regular multiport on Direct injection engines so they sort of have both.. very cool. In europe a few vw's and Audi used engines like that but it wasnt h20/meth. They had both direct injection and multiport but just gas on all. The cars computer would switch depending on hwy driving or city or performance driving. But, aside of this intercooler or no intercooler topic. I hope my idea has merit. I haven't run the numbers to really know and def haven't had 2 identical cars and the $ to go play with the idea soooo, who knows..someone does? I dont know which is better. Now in F1 cars, they have aero space designed, polished carbon fiber intercoolers & short charge pipes so they will always have a gain with an intercooler but that is Apples and Oranges. In a sedans engine bay, (like any BMW as we know as an example), you have a whole other set of issues. I dont think some really get into the fine details. A lot of things beside heat can rob power from your car. Im not doing this either except to try to get creative with some high temp VITON

, high temp rated tubing. Its flexable with a very special "coil" to keep it from collapsing. Its not available pre-bent into certain shapes to my knowledge, but its surprisingly flexible but its I.D. doesn't change. It also has a sort of "liner", inside its entirety and it gives it very good air flow through. It's very pricy but what doesn't on a build. Ive considered using it for a while. I worked ffor a company that made plasma torches for all manor of industries.. these were huge ones..likex14 inch ooenings on the front electrodes. They used thid Vinton tubing allnover the place and these torches got over 12,000 degrees f. Yes 5 digits...no mistake. They cut up US M1 Abrams tanks like butter. They were used in sooo many technologies. We made small ones that were 6 inch around for universities to use.. 100kilowatt torches but some had to have thier own sub stations and used 12 phase power to emulate DC power. These used 10-14 megawatt torches!!! and even bigger ones used in countries like Korea for municipal waste removal I could get way technical...lol
This is rambling on so im gonna go. Im new and found this forum looking for intercooler knowledge. Sorry if my 1st post is too over the top.
Thanks