AEM Cam Angle Sensor Disc – Nissan SR20DET RWD / KA24DE | 50mm OD | AEM EMS CAS Trigger Disc

The AEM Cam Angle Sensor (CAS) Disc for the Nissan SR20DET RWD and KA24DE is a purpose-made trigger disc engineered for use with AEM programmable engine management systems — replacing the factory cam angle sensor disc inside the distributor with an AEM-compatible disc that provides the correct trigger pattern for AEM EMS cam position sensing. The CAS disc is a critical component in the AEM EMS installation on Nissan platforms that use a distributor-based cam angle sensor — the factory disc's trigger pattern must be replaced with the AEM disc to allow the AEM EMS to correctly read cam position for sequential fuel injection, ignition timing, and closed-loop engine management. This disc is the 50mm OD variant, correct for the SR20DET RWD and KA24DE applications. Verify that the AEM CAS disc's centre hub profile matches your factory distributor disc exactly before ordering — hub mismatch will prevent correct installation.

Key Features:

• AEM EMS compatible trigger pattern — engineered with the correct trigger disc pattern for AEM programmable engine management systems — provides correct cam position signal for sequential fuelling, ignition timing, and closed-loop engine management
• 50mm OD — 50mm outer diameter — correct for the SR20DET RWD and KA24DE distributor CAS applications — verify OD and hub profile match your factory disc before ordering
• Direct fit — installs inside the factory distributor in place of the factory CAS disc — no distributor modification required when the correct disc is selected
• SR20DET RWD and KA24DE specific — engineered for the RWD SR20DET (S13/S14/S15 Silvia, 180SX) and KA24DE (S13/S14 240SX) distributor CAS applications
• AEM quality — manufactured by AEM, one of the most respected engine management and performance electronics brands in the aftermarket

What Is the CAS Disc and Why Does It Need to Be Replaced?

• Factory CAS Function: The Nissan SR20DET and KA24DE use a distributor-mounted cam angle sensor (CAS) to provide cam position information to the factory ECU. Inside the distributor, a slotted disc rotates with the camshaft — an optical or Hall-effect sensor reads the slots as the disc rotates, generating a trigger signal that the ECU uses to determine cam position for fuel injection timing and ignition timing.
• AEM EMS Requirement: AEM's programmable engine management systems require a specific trigger pattern from the CAS disc to correctly interpret cam position. The factory disc's slot pattern is designed for the factory ECU's trigger interpretation — it may not provide the correct signal pattern for the AEM EMS to accurately determine cam position for sequential injection and ignition control. The AEM CAS disc replaces the factory disc with one that provides the correct trigger pattern for AEM EMS operation.
• Sequential Injection & Ignition: Correct cam position sensing is required for sequential fuel injection (injecting each cylinder at the correct point in its intake stroke) and for accurate ignition timing on a cylinder-by-cylinder basis. Without a correct cam position signal, the AEM EMS cannot operate in sequential mode and must fall back to batch injection — reducing the precision and efficiency of the fuel delivery. The AEM CAS disc enables correct sequential operation.

Critical Fitment Verification — Hub Profile Match:

Before ordering, verify that the AEM CAS disc's centre hub profile matches your factory distributor disc exactly. The CAS disc mounts to the distributor shaft via a centre hub — the hub profile (shape, keyway, and dimensions) must match the factory disc's hub to allow correct installation on the distributor shaft. AEM produces multiple CAS disc variants for different Nissan applications — the 50mm OD disc (AEM30-8760) is correct for the SR20DET RWD and KA24DE, but the hub profile must be verified against your specific distributor before ordering. A hub mismatch will prevent the disc from seating correctly on the distributor shaft and will result in incorrect cam position sensing or inability to install.

Specifications:

• Brand: AEM
• Part Number: AEM30-8760
• Barcode: 30-8760
• Outer Diameter: 50mm
• Application: Nissan SR20DET RWD / KA24DE — distributor CAS
• Compatible EMS: AEM programmable engine management systems

Fitment Information:

• Nissan SR20DET RWD — S13 Silvia / 180SX / S14 Silvia / S15 Silvia (RWD SR20DET applications)
• Nissan KA24DE — S13 240SX / S14 240SX
• For use with AEM programmable engine management systems only
• Critical: Verify that the AEM CAS disc's centre hub profile matches your factory distributor disc before ordering. Remove the factory disc from your distributor and compare the hub profile to the AEM disc before installation. Hub mismatch will prevent correct installation.
• Note: The SR20DET FWD (Pulsar, Primera) uses a different CAS disc — this disc is for RWD SR20DET applications only. Verify RWD vs. FWD SR20DET application before ordering.

What's Included:

• AEM cam angle sensor disc — 50mm OD — Nissan SR20DET RWD / KA24DE (AEM30-8760)

Installation Notes:

• Remove the distributor cap and rotor to access the factory CAS disc inside the distributor
• Note the factory disc's orientation before removal — photograph the disc position relative to the distributor housing for reference during reinstallation
• Verify hub profile match between the AEM disc and the factory disc before proceeding — do not force the disc onto the shaft if the hub does not seat correctly
• Install the AEM disc in the same orientation as the factory disc — incorrect orientation will result in incorrect cam position sensing and engine management errors
• Refer to AEM's EMS installation documentation for complete CAS disc installation and EMS configuration instructions — the AEM EMS must be configured for the correct CAS disc pattern after installation
• Professional installation by an experienced AEM EMS tuner strongly recommended — CAS disc replacement is part of the AEM EMS installation process and requires correct EMS configuration to function correctly

Why AEM?

AEM (Advanced Engine Management) is one of the most respected engine management and performance electronics brands in the aftermarket — known for their programmable ECUs, wideband controllers, air/fuel meters, and engine management accessories for a wide range of Japanese and domestic performance platforms. AEM's SR20DET and KA24DE EMS solutions are well-established in the S-chassis community — and the CAS disc is a fundamental component of the AEM EMS installation on these platforms. For S-chassis owners running AEM engine management who need the correct CAS disc for their SR20DET RWD or KA24DE application, AEM30-8760 is the correct part.

Perfect For:

• Nissan SR20DET RWD (S13/S14/S15 Silvia, 180SX) and KA24DE (S13/S14 240SX) builds running AEM programmable engine management that require the correct CAS disc for sequential injection and ignition operation
• S-chassis AEM EMS installations where the factory CAS disc must be replaced with the AEM-compatible disc as part of the engine management system installation
• Replacement of a worn, damaged, or incorrectly specified CAS disc in an existing AEM EMS installation on an SR20DET RWD or KA24DE platform

Critical Note: For use with AEM programmable EMS only. Verify hub profile match with your factory distributor disc before ordering — hub mismatch prevents correct installation. RWD SR20DET only — not for FWD SR20DET applications. Professional AEM EMS tuner installation recommended. Refer to AEM's EMS documentation for complete installation and configuration instructions.