
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.

Fitting a strut brace and performance benefits "Strut your funky stuff" Think of a car like a shoebox with no […]
Benefits and drawbacks of engine water injection systems
You’ve finished tuning up your engine but you find that at full throttle the engine splutters or stalls. When you get the car on a diagnostic you find that the knock sensor is kicking in to protect the engine.
Engine knock is a condition where the fuel inside the engine ignites prematurely and occurs within an engine running at high compression. (It can also be caused by other factors including low octane/poor quality fuel or hot spots within the engine.)
Suspension settings, lowering and stiffening
On the track your priority is fast cornering and suspension plays a large part in this. Track conditions are quite forgiving and you can make some compromises like using hard suspension and lowering the car for optimum aerodynamics and a low centre of gravity.
This works well because tracks are fairly flat and you do not have a carrier bag full of eggs in the car from your return trip to the supermarket.
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