4 feet? or 4 inch thick?
either way it sounds FUCKING huge for that turbo
he must have lag out the ass with that thing
hmmm, so when he gets boost its blowing the pipe off?
is the intercooler new? and of good quality?
either your connections/clamps are shit, which is very likely, or it could be that the intercooler is clogged and creating too much pressure causing the tubing to blow off, or perhaps the wastegate isn;t operating correctly also allowing too much boost...
either way it sounds like you need to upgrade your connections, and it would be a good idea to make sure the intercooler isn't a big pile of shit...
and he wants it to be clean?
look to upgrade the manifold? well, what kind does he have, homemade? or aftermarket? get a clean looking manifold, degrease the turbo, then you can try and polish it or paint it, paint will most likely NOT last due to high temps, but high temp paint might last a lil longer...