At my friend Bryan’s repeated insistence (nagging) I checked the base timing (alignment of the camshafts and crankshaft) in my Evo. Took me a couple tries to do it right, but lo and behold, it turns out that somehow, my timing belt had skipped a tooth. I don’t know when or how it happened but it’s clear the car has been this way for some time now, because once I corrected the problem, many of the little issues that had been plaguing it improved greatly or went away altogether. Moreover, the car is now making the power I would expect:
Peak power has increased by almost 30 horses at the wheels (and much higher throughout), torque no longer falls like a rock towards redline—almost 40 lb-ft of torque more than before above 5500 RPM.
I’m pleased as punch. This has been the root of the mysterious problem that I’ve been chasing for several weeks now. With it solved, I should now be able to tune the car and shoot for the 300-horsepower mark.