[Sluttypatton]

There is a whole new set of problems incorporated with retarding the ignition timing, so while retarding ignition timing can be a valuable tool when tuning a motor, one must keep it within reason. Also keep in mind that retarding the ignition timing kills power.

Running lean is bad for a few reasons, but good for one main reason. Running lean can cause detonation in motor that isn't set up to safely do so, however motors actually make the most power when they run a little leaner than 14.7:1, somewhere around 12:1. The reason 14.7:1 is used on road cars is because that is where vehicles make the lowest emissions, and it gives better detonation resistance.

As for lowering the compression ratio with rods and gaskets, it is bad if you don't know what you are doing. I never said it was impossible to do, just that if you don't know what you are doing you can mess up the squish area and actually make your engine more prone to detonation. SaabJohan was a little more specific in that area, I believe he was saying that the relationship between the parts in the combustion chamber is complicated and have a very synergetic effect, changing one thing may change the whole dynamics of the combustion chamber.

Remember that on turbocharged cars, blow off valves are not used to control boost levels, just vent the pressure that builds up at the throttle plate when it is closed, and prevent compressor surge. However, pop off valves are like radiator caps, they open when the pressure reaches a preset level, these can be used to control boost to the engine, as once the boost pressure reaches a certain level they will open and vent excess boost to the atmosphere.