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Mar 28, 2019

Nissan Skyline Crank Angle Sensors : CAS


R34 CAS on the left, R32/R33 on the right

Nissan CAS or crank angle sensor is a crankshaft position sensor driven from the exhaust cam. The CAS sometimes accidentally called a cam angle sensor, has an optical wheel inside that is driven at 1/2 crank speed.  It has two sets of slots inside. One set is 360 one for each degree. The other set of slots is 6 or one for every 120 degrees of crank rotation. You will often see the signals labeled as the 1 and 120 signals.   The CAS allows you to adjust base ignition timing on an RB engine.    There are several different part's and part numbers for them.  There are Mitsubishi and Hitachi sensors.  There even a couple of shapes of the R32/R33 sensor.  The late R32, and early R33 sensors had a slightly different shape than the early R32, and R33 later sensors that were all the same.

RB26 Hitachi Crank Angle sensor.  
The Mitsubishi and Hitachi crank angle sensors are interchangeable between R32/R33 GT-R.  You don't have to replace them with the same sensor. Just the look is different.

Crank Angle Sensor Part Numbers


There are three different CAS, two are functionally identical but look different. The early cars R32 89-93 ish got Mitsubishi sensors. Then for some wild amount of time in there, they got Hitachi sensors for the 93/94 and early 1995 cars. Then it was back to Mitsubishi. I don't really care enough to be exact, as the function seems to be the same.  The R34 CAS has a plastic cover and is both driven, and signals come out on different pins. 

CAS gasket - IMPORTANT to space the CAS correctly. 13525-58S00

R32/R33

23731-02U11

 - Mitsubishi

23731-08U00 - Hitachi 

R32 GT-R with timing anti tamper tape applied


R34 cam angle sensor
23731-5L300




Notice the drive on the R34 CAS on the left, and the R32/R33 on the left




CAS Wiring
R32/R33 
Pin 41  120 Signal
Pin  42 1 Signal
Pin 51 120 Signal
Pin  52 1 Signal





R34
Pin 41 1 Signal
Pin 42 120 Signal
Pin 51 Blank
Pin 52 120 Signal

R34 GT-R ECU pinout or wiring diagram for computer
R34 GT-R ECU pinout or wiring diagram for computer


Other options:




Other options involve not getting the crank position from the cam gear.  The problem with getting the reading at the cam is that the belt stretches and flexes a little bit.  Add in the wheel inside the CAS fluttering a little, and having 360 little, teeny, tiny slots, you can get some crank/ignition timing errors.  If you have a stock car, at stock power, the OEM CAS works fine. If you are making 1000 hp, turning 10,000 rpm, then you need to go to a crank pickup.

With a crank pickup, you also need what is called a 1 signal. Since the crankshaft spins around 720 degrees, or two turns in every complete combustion cycle, the ECU needs to know when it is at top dead center (TDC) on #1 cylinder during the compression stroke, to fire the spark plug.

In recent years, lots of companies have come up with kits to read the crank position.  Here are a few.


Nissan RB (Twin Cam) Crank/ Cam Trigger Kit from Ross Performance
Kit includes the following:
  • Nissan RB Harmonic Damper with 12 or 36-2 Tooth Integrated Trigger Disc
  • Nissan RB Crank Angle Sensor Mount (306000-75) OR Nissan RB Crank Angle Sensor Mount to Suit Girdle (306000-75-SP1) SP1 mounting spigots are 10mm shorter than standard.
  • Nissan RB Cam Angle Sensor Mount (306000-74)
  • Nissan RB Twin Cam Trigger (306000-73)
  • Honeywell GT101 Hall Effect Sensors (992GT101) OR Cherry Hall Effect Sensors (992CHERRY)
This Kit is designed to suit the following engines; Nissan RB20DET, Nissan RB25 NEO, Nissan RB25 R33, Nissan RB26 R32 GTR, Nissan RB26 R33 GTR and Nissan RB26 R34 GTR

Platnium Racing Products Trigger kit


Platinum Racing Products have a number of RB trigger kits available.  Here is one option, pictured above.

This RB Trigger kit has evolved, through research and development to offer precision ignition timing, for high powered and high RPM applications.
We have re developed the bottom timing gear with trigger disc to be one piece, this disallows a screwed on trigger disc to ever come loose.
This custom made gear will work with all and any balancer.
The cherry hall effect magnetic pickup timing gear sensor is now the industry benchmark, the cam sensor bracket is light and simple and incorporates the use of a smaller more discreet cherry sensor.
Design Features:
  • Engineered timing gear with incorporated trigger disc.
  • Gear works with any known balancer.
  • Custom colours available upon request.
  • Bolt kit included.
  • Lifetime warranty on all Platinum Racing Products hardware.

For the full list of options, check out the PRP site.   

Buy USA Legal R32 and R33 Skylines at Importavehicle.com!
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