ok herez why they do that!
the way TURBOCHARGERS work is there is a shaft the runs between the compressor hosing and turbin hosing. the compressor hosing only touches CLEAN air...it is sucked up from the compressior wheel and does in and into you intercooler. *now the the shaft spins becuase the it is connected to the other end to the turbin wheel, which is turned by the EXHAUST FUMES that come out of the engine!...it pushed the turboin wheel and goes on to the exhaust
what your saying would make CLEAN and dirty air comeinto the engine...like sticking your muffer to you throttle body!...not smart!...thats why both sectons and air tight and wont let anything from the other side in!!!!!
for super chargers go to the * and replace with a gelt driven pully connected to you car! <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt='
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