Engine Performance problem
1996 Mazda RX7 Two Wheel Drive Manual 95000 miles
initially my engine misfires when it reaches 5000 revs, after installing new plugs, second hand plug cable n coil and a new Apexi power fc ecu, the misfires hasbeen delayed to 6500revs at dyno at 280hp. What can I do to stop the misfire n push it to its red line limit? I planned to push its power band to 400hp, what are the modifications needed and is it reliable?