Berg wrote:Thanks Manchild,
But I’m not sure that there’s no compressor needed because I believe I have read an article said that the pressure may change with change of rpm and engine load (unfortunately I cannot find the article now). It is impossible to change the pressure during pitstop, either because of its irresponsiveness and its time consumed.
As Dave said, there is a bottle of compressed gas that is part of this system. Pressure in a gas canister is higher than pressure needed for pneumatic valves and there is a valve between bottle and the pneumatic valves that can add pressure from the bottle to the system.
It is very possible to change the pressure during pitstop and it is nowadays general practice to add more gas during pitstop if the gas starts leaking and it was done many times. Mechanic just needs to plug in a hose and the gas container is filled in a flash.
Even more, it doesn’t take a pitstop to change pressure if the system isn't leaking - it can be done automatically by presets of ECU or manually by driver. All it takes are two electric valves - one one-way valve between compressed gas canister and the system (increase) and another one between the system and the atmosphere (decrease).
With compressor you’d get much slower response than with electric valves that can increase and decrease pressure immeasurably quicker. The only thing that compressor could do would be pressuring up the gas container if the chamber had a piston so that compressor pumps the air that moves the piston in direction of side of the container filled with gas.
However that could be used only in case when there is a leakage and when there is a leakage it usually ends up in engine blow regardless if the system was additionally pressured up. Having a compressor (additional weight) only for those cases is something no constructor would apply on engine that intends to run leak-free.
http://scarbsf1.com/valves.html