Part 2: Providing sources of vacuum and pressure to systems that require them.
Now that everything is out, prepare to install your own vacuum lines.
The FPR must see vacuum and pressure to function properly because it increases or decreases fuel rail pressure according to manifold pressure. The most direct way to connect the FPR is to use the large forward-facing port on the plenum. Notice that the nipple sizes are not the same.
As you can see above, the cleanest method of connecting the FPR to a pressure/vacuum source is to use a plastic T: Plenum portTFPR. Not only can you get a plastic T with differently-sized ports to solve the nipple size problem, but you can also then run a vacuum line from that T to the BOV, which also requires a vacuum/pressure source to operate properly.
Connecting the wastegates: The WGs do not need a vacuum signal; they need only a pressure signal. My preferred method is to run a lines from the wastegates to a T located roughly where the thermostat housing is. Make these lines equal length and as short as possible. Be reasonable: do not make them so tight that you can pluck them like guitar strings. Run a line from the remaining port on the T to the MBC or BCS (depending on setup). This portion of the house routing is unique. Place the MBC or BCS wherever you prefer. Mine is on the firewall. Finally, connect your MBC or BCS to nipple on the back of the Y-pipe. Usually I just attach an excessively long line to the MBC or BCS “in” port until the very end, and then cut the line to length once I’ve installed the Y-pipe.
In this photo, I am holding the rear WG line. The tee is at center. Top line goes to BC and right line goes to front WG.
Because the EVAP canister is out, gasoline fumes will now vent into the engine bay, which is less than desirable. There are 2 easy options: Cap the hardline with a vacuum cap, or run a length hose from the hardline out the front of the bumper. I prefer this second method because pressure does not build in the tank. Ultimately, the best way is to remove the rock guard, cut the hardline back at the tank, and remove the hardline entirely.
If you have a boost gauge, connect it to a vacuum/pressure source like the nipple on the back of the plenum. If you have other switches or units (hobbs switches, MAP sensors), connect them.
Part 3: Capping unused ports
To prevent intake tract leaks it is important to cap all unused nipples. There are two on the pre-turbo intake pipes: A small one on the rear turbo pipe (recall that it was used to reintroduce bled air on the stock BC system) and a large one on the front turbo intake pipe.
For the rear, use a vacuum cap (I like to slather a little RTV on there too).
For the front, you may simply use the EVAP canister valve because it defaults to the closed position.
Advanced techniques: Fill the port with RTV or, if you wish to be challenged, find a vacuum cap in that size that seals well. I prefer the RTV.
Cap the nipples on the throttle body.
(photo)
If you have EGR blockoff plates, install them now.
Part 4: Reinstallation
Reinstall the intake piping and the coolant reservoir. It will likely be much easier now. Ensure that you do not pinch the WG signal lines.
At this time, you will also want to connect the BOV. If you removed the BOV with its stock vacuum line attached, and it will reach, connect it to the T between the large plenum nipple and the FPR. If the line will not reach, simply make a new one.
Similarly, you should remember to cut to length and then attach the MBC or BCS to the Y-pipe nipple.
Clint
