I re-did the IC setup yesterday. The new setup benefits from:
1. Venting to the outside.
2. Vaccum under the bus should help pull more air through.
3. Less piping near the exhaust which should mean lower temps.
4. I was able to use a slightly larger fan (from siliconeintakes.com). This fan should push more air and is pleasantly quieter than the Derale 7" fan I had on the old setup.
I had avoided this initially because I didn't want to cut a hole in the battery tray.
The new setup uses the stock 1Z intercooler, which I cleaned thoroughly before using. (This is a bigger job than it sounds ;-)
Initial impressions are very good, I seem about 20* or more lower than I was before. The real test is a sustained hill at boost. I was seeing over 170* in that situation before. I've been told on the Vanagon TDI group that 140* is somewhat normal.
If temps are still too high, I am going to enclose the IC so that air from the vent creates some pressure to move more air, also the enclosure will keep engine heat further away. For now, I'm going to run it as it is.
So, from the turbo we have a 90* 1.5" to 2" reducer, going to a 2" 45* aluminum tube going to a 90* 2" elbow which takes us into the IC.
Here's the IC itself showing the entrance from the turbo and the exit at the wheelwell. The exit is also a 90* 2" elbow.
Here's where the output of the IC connects to the tube leading to the intake. There's the 90* elbow coming out of the IC, a short 5" tube and another 90* elbow. From there, we're into the stock tube which holds the boost nipple and the IAT sensor.
Not shown, but somewhere in this thread is the last part of the intake which is easy. At the top of the plastic IAT/boost tube is a 90* 2" elbow connecting to the stock intake manifold.