Basically the same thing for all RB engines:
Timing an RB20DET By: goofynick Warm up car to operating temp. Make sure idle is 650 +/- 50 rpms. You can adjust your idle RPM's with a flathead screwdriver by turning the screw on the AAC. You have to unplug the brown plug from the AAC first, then plug it back in. Unplug the TPS (not the idle switch, but the tps, has the cord hooked to the plug coming out of the sensor). Hook up timing light around the loop at the back of the engine coming out of the ignitor pack (black wire loop). Check timing, if way off, then flip the way the thing is connected around that loop. Set to 15 degrees for manual trans, 20 for auto with car in neutral, do so by loosening 3 bolts on cam angle sensor and rotating it left or right. Tighten CAS. Plug tps in and rev engine, then unplug TPS and check again to be sure it is at 15 degrees with idle around 650rpms. Shut off the car and uplug everything the timing light, plug tps back in and unplug battery for 10 mins. Hook up the battery, restart the car and go drive it hard for a few minutes.
Source: http://forums.nicoclub.com/adjusting-timing-on-an-rb20det-t218636.html