In the case of the EJ engine in the Impreza an engine overhaul is highly recommended with the camshaft upgrade. The Tomei Powered camshafts are efficient with the stock boost from low RPM up to a bolt on aftermarket turbo. Since AVCS is supported the results are impressive from idle all the way to 7500 RPM. Due to the precision and accuracy of the product choosing the right size shims is easy and reliable even at higher engine speeds. The added benefits is that the designs are suitable for both 2.0L and 2.5L EJ variants which makes it available for the Forester owners as well and highly recommended for international Impreza models.