The RB series engines including the infamous RB26 have proven them selves to be one of the most popular inline six JDM engine platforms of all time. With huge after market support the RB26, RB25 and RB20 have been given a “rebirth” providing a great engine option to anyone looking to run on one of Nissan’s most iconic engines. Using new tech like the PRP Cam & Crank trigger kit is just one of the key ingredients to brewing the perfect RB26. Below we will discuss how the OEM cam/crank triggers are prone to timing errors that are easily solved by using a PRP RB series crank trigger kit.
Cam & Crank Trigger Methods
In factory form the RB series engine uses a “one piece style” Cam & Crank sensor combo. This means the Cam and Crank positions are both referenced off the exhaust cam by the “CAS”. There is no actual sensor or reference on the crank shaft in OEM format. While using the cam to reference the crank position does work it presents a problem when the engine is under heavy load and the timing belt stretches. This stretching of the timing belt means the crank is actually farther advanced than the cam (when compared to the engine under low load). Because the crank is farther advanced than the ECU knows based on the OEM CAS the ignition timing the ECU provides to the engine is actually retarded by as much as 4-6 degrees.
Here at Brewed when we are building or tuning a RB engine we always recommend using one of the Platinum Racing Products crank trigger kits. PRP offers an elegant solution to the RB series Cam/Crank sensors and associated timing problems by separating the cam and crank sensor. In this new 2 sensor lay out the ECU is always provided an accurate crank position reference regardless of timing belt stretch. Placing the crank sensor directly on the crank shaft to reference either a 12 tooth trigger kit or a high resolution Pro Series 36-2 tooth trigger kit is key to ensure the ECU is always getting accurate engine position data. PRP trigger kits are a simple and effective bolt on solution for any RB engine. We use the classic PRP crank & cam RB trigger kit with our plug and play AEM Infinity 506 RB26 GTR packages. The PRP Pro series RB26 crank trigger kit with a 36-2 trigger is perfectly paired with our Motec M1 series ECU packages. With the crank reference well taken care of we move onto the cam trigger. PRP RB series cam trigger kit handles the cam position reference and is easily adjusted to ensure the crank position sensor is at the optimal position half way between 2 of the crank trigger teeth.
RB26 GTR using PRP Cam/Crank Trigger Kit
Here is one example of a R34 GT-R we set up with the PRP cam/crank trigger kit paired with our AEM Infinity Plug n Play ECU package. The PRP trigger kit is a must for this 2.7 Liter Tomei stroker making over 700whp. Ensuring accurate engine position data to the Infinity ECU allows us to set up and tune individual cylinder knock trims allowing this engine to run safely at 31psi on pump gas (93ron/mon). With the ECU referencing the 12 tooth trigger on the crank we are guaranteed accurate ignition timing. (This is where the stock Nissan CAS falls short!)
Installing PRP RB26 Cam Sensor/Trigger Kit
Installing the PRP RB series cam trigger kit is a bolt on experience and with the wide range of anodized colors to choose from a great way to add some eye candy to your engine bay. This particular R34 customer wanted to math with his HKS cam gears so a nice purple anodize was chosen. Stay tuned for full step by step DIY install article.