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RB25DET Vacuum source and Alternator wiring schematic

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I've been working on installing a RB25det series 2 motor in a '73 S30.  Two issues I am having trouble resolving are probably simple but not for me.

Existing configuration is a series 2 RB25det motor with a Greddy style intake manifold.   I  need to find two things, preferably with a picture  and/or schematic.  

!. Alternator wiring connection. 

2. Vacuum source.


Any help is appreciated



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Waste gate vacuum attaches between the turbo and the throttle body. Outside of that, location really doesn’t matter that much. Closer to the turbo is probably safer. Most internally wastegated turbos have the vacuum reference on the end of the compressor housing outlet before plumbing starts. The RB25 is no different except it first goes to a boost control solenoid.


You’re supposed to connect the brake booster the bigger hole on the underside of the manifold in the center. Unless you’re not in the US, It’s BSPT, so use the nipple that came with the manifold or have it re-tapped to a common pipe thread. I retapped mine for 3/8 NPT and am using it for my megasquirt IAT; since I’m not running a brake booster.


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