hi ihave a 2001 1.4 civic (6th gen) has anyone got any info/reviews on the following mods: powerboost valve, denso/splitfire spark plugs(which one would be better) and splitfire ignition leads.
While I'm not familiar with the power boost valve specifically, it looks similar to a rising rate fuel regulator which is used more for forced induction applications like turbocharging and supercharging. If you were to install this on a relatively stock car you would risk running an extremely rich mixture that the stock ecu would be unable to compensate for which in turn could cause damage to your engine. The stock fuel regulator that currently sits in your car is more then sufficient enough to keep up with simple bolt on parts and shouldn't need replacement unless you are planning on doing true engine work or forced induction. As far as comparing different companies' spark plugs and wires it would really be a matter of splitting hairs.