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Back in the good old days – the task of timing the ignition spark was performed by the distributor. The greater the RPM, the more the timing would advance.
This did a reasonable job but for the most effective power you would need to vary the timing to a greater degree than a fixed ratio advance curve. The electronic ignition system was borne.
Blow off valves, dump valves and screamer pipes
Blow off valves and dump valves.
When the throttle is closed (when you lift off the accelerator) in a turbo driven engine there is a build up of pressure as forced air is still coming from the turbo. Lifting off the throttle is a lot like putting a plug in the sink – the flow through is stopped and water would just build up and overflow the sink.
The inlet and outlet ports on the engine block are usually larger than those of the manifolds that connect to them.
This allows for scope in the manufacturing process to allow for mismatched alignment.
Generally the engine ports are larger in the upstream flow direction avoiding turbulance but power gains can be made by matching these up.
Big valve kits – larger intake valves.
The heads primary job is the mixing of fuel and air and delivering this to the combustion chamber.
Any turbulence or drag can restrict the air flow into the engine starving you of power. So this TorqueCars article will focus on the intake valves and how they can be improved.
The aim of head tuning is both to maximise the amount of air and fuel that gets into the engine, and to improve the mixture.
