\nTo better understand how important inlet air density is, it is sufficient to analyse the behaviour of the car as it climbs in altitude. As the air density decreases in the mountains, this results in a power loss of about 1.5% for every 100 metres of altitude, which then at around 1000 metres will be about 15 %.
\nDump Valve<\/strong><\/p>\n
The Dump valve protects the compressor impeller from stresses that occur following a rapid release of the accelerator pedal while the engine is under full load, the so-called 'water hammer'.<\/p>\n
In fact, the sudden reduction in intake valve lift and the closing of the throttle valve generate a pressure wave that propagates throughout the column of suctioned air up to the blades of the compressor impeller. This wave imparts an opposite thrust to the rotation of the impeller, causing a torsional stress that is detrimental to the compressor components.<\/p>\n
The Dump valve seat, integrated into the compressor, when controlled by the CCM connects the outlet duct of the impeller with the suction duct of the compressor. Therefore during cut-off or when the boost pressure limits are reached, the valve opens in order to release the overpressure in the discharge duct.<\/p>\n
![\"Overboost](\"http:\/\/www.garagetorino.com\/tecnica\/immagini\/Turbo\/04.gif\")
<\/p>\n
System flow diagram<\/b><\/p>\n In the next part (the fourth) we discuss typical errors involving supercharging systems, drawing on cases that have actually happened to us and which will certainly be helpful in understanding how to deal with new cases.<\/p>\n See you next time.<\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/p>\n <\/p>","protected":false},"excerpt":{"rendered":" We left off with the promise to delve deeper into the operating logic of the other components of the supercharger system and [...].<\/p>","protected":false},"author":49,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[26],"tags":[],"acf":[],"featured_image_urls":{},"appp_media":null,"views":1239,"_links":{"self":[{"href":"https:\/\/www.checkstar-techblog.it\/en\/wp-json\/wp\/v2\/posts\/4151"}],"collection":[{"href":"https:\/\/www.checkstar-techblog.it\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.checkstar-techblog.it\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.checkstar-techblog.it\/en\/wp-json\/wp\/v2\/users\/49"}],"replies":[{"embeddable":true,"href":"https:\/\/www.checkstar-techblog.it\/en\/wp-json\/wp\/v2\/comments?post=4151"}],"version-history":[{"count":0,"href":"https:\/\/www.checkstar-techblog.it\/en\/wp-json\/wp\/v2\/posts\/4151\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.checkstar-techblog.it\/en\/wp-json\/wp\/v2\/media?parent=4151"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.checkstar-techblog.it\/en\/wp-json\/wp\/v2\/categories?post=4151"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.checkstar-techblog.it\/en\/wp-json\/wp\/v2\/tags?post=4151"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}\n
\nIn normal turbocharger operation, regulation of the maximum boost pressure is effected by opening the waste-gate valve (8). In fact, in the actuator diaphragm (9) the boost pressure, i.e. the pressure existing upstream of the compressor, is always applied. This pressure creates a thrust on the diaphragm; when this thrust exceeds the antagonist thrust of the reaction spring, the waste-gate valve (8) opens and a part of the exhaust gas is diverted from the turbine, depriving the latter of its force.<\/li>\n
\nWhen the winding (5) is magnetised by the CCM, the valve (7) connects the boost pressure from the duct (6) to the intake duct, i.e. downstream of the compressor, by relieving the existing pressure on the actuator diaphragm (9): the reduction of the thrust on the actuator diaphragm causes the waste-gate valve (8) to partially close, so that more gas goes to the turbine, increasing its speed and thus that of the compressor, thus increasing the boost pressure.<\/li>\n
\nWhen the throttle valve (10) closes, the vacuum transmitted from the duct (2) connected to the intake manifold opens the valve (3); this opening allows the pressure downstream of the throttle (closed), to discharge downstream of the compressor and cancel the pressure waves that cause 'water hammer'.<\/li>\n<\/ul>\n![\"\"](\"http:\/\/www.checkstar-techblog.it\/wp-content\/uploads\/2015\/11\/silvia.jpg\")
<\/p>\n