Work was stalled a bit while I considered materials for a large volume vacuum chamber. The goal is for the stock Ford Manifold Absolute Pressure/ Intake Air Temp MAP/IAT sensor to get similar readings as in the stock manifold. This meant I should be inside the air box for good temp readings. It should also be a large volume so different feeds would equalize and give an average manifold vacuum similar to stock. I wanted a thin walled ABS pipe that I could cut a hemispherical section longways out of the pipe and weld it to the top of the air intake housing. There is a small positive crankcase ventilation (PCV) chamber there already. The chamber will have access to two large stock inlets in the Suzuki housing. You can see these in the pic I posted above. One will be a PCV air feed. One will be direct manifold vacuum suction. Because I am using a section rather than a pipe, the top will be available to mount the MAP/IAT sensor. I may need to weld a little ABS pad to mount it to the proper thickness of material. Vacuum will be right under neath the sensors mounting pad. The chamber will extend all the way to the drivers side, installed. This might be a good place to mount the Idle air control (IAC) motor. IAC Wiring will then be unaltered. It will suck filtered air just below my vacuum tank and then inject the air into the vacuum chamber just above the bottom wall of the chamber. Pics to come.
I had trouble finding suitable material. I wanted ABS so I could plastic weld it on, but I wanted thin walls so it would have a decent internal volume. This ribbed shop vac extension should work out fine if it will weld. My 2 inch manifold runners were very thick walled, as was all the ABS pipe at McMaster.com. Thining the wall of my 2 inch OD piece out of a 12 inch long section would have been quite a job all by itself.
john
