I noticed that off the intercooler going into the intake manifold, there is actually a pipe instead of a hose. Now it would seem to be ggod reasoning to make a pipe instead of a hose for simple fact that the pipe would not be affected by the boost the turbo puts out. In other words the hose, unlike the pipe, has tendenacy to "swell" under heavy boost, so wouldn't be more "efficient" to have pipes instead of hoses? Just a wondering brickster :)
91-940T

So what if the hose swells slightly under pressure? There would no performance change even if you went to an exotic system of tubing and expensive wire braided hoses.

Yes, the engine moves...which explains the pipe-to-throttle body hose.
The intercooler to pipe hose is there because a hose/clamp is the simplest/cheapest solution to connecting the two.

Yes, there are flexible connections that don't bulge or deteriorate like a hose/clamp (think flexible metal bellows connection) but they're more expensive. Or large braided stainless steel hose with teflon liners...again more expensive.

The engine moves in relation to the car, so some flexibility is needed.
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Warren Bain - '86 744Ti M46 >290Kmi, '96 965 >100Kmi Wifemobile near Manassas Va..

I have a BMW 524 td that only uses hoses as couplings. All of the runs from the turbo to the motor are aluminum with the hoses used as couplings. It doesn't have an inter-cooler so the piping is a little simpler than on my 740.