AEM "Tru-Time" Adjustable Cam Gear for Mitsubishi Lancer Evo 8AEM "Tru Time" Adjustable Camshaft Gear Specifications Ideal for tuned engines the AEM camshaft pulleys are made of forged aluminum and have an exemplary black anodized finish. The teeth benefit from a special surface treatment ensuring optimal contact with the timing belt without affecting its lifespan. AEM "Tru Time" adjustable camshaft pulleys have many advantages : On a stock engine they optimize the timing of the engine to gain torque and horses.