MSR Technical Centre
Research & Development: Camshafts
 
As an engine builder and tuner that prides himself in his work, attention to detail is a must. As a result, over the years, I have found that the camshafts in Subaru turbocharged engines can have up to 6° of movement in the camshaft dowels. This results in inconsistent performance from an engine. Not setting camshafts correctly and properly can greatly affect power.
 

"To emphasise how critical it is to set camshafts correctly and properly, on many occasions I have been able to produce power gains of up to 50awkW by simply setting the camshafts."

I have also found that the brand of timing belt used in an engine have an affect on cam timing as they wear out and stretch over time. Even if a timing belt has stretched by only a fraction, it is enough to throw one of the four camshafts in a Subaru turbocharged engine out by up 2°. It may not sound like much at all, but 2° in addition to the 6° of movement in one cam alone will affect overall performance immensely. After extensive testing with different branded timing belts, the OEM Subaru timing belt and the Subaru STI timing belt offered the most consistent results over the standard 100,000km period.

To emphasise how critical it is to set camshafts correctly and properly, on many occasions I have been able to produce power gains of up to 50awkW by simply setting the camshafts. So when you think camshafts only make up a fraction of the power to be gained, think again.