Turbocharger query

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Tue 29 Nov 2005 14:34
Turbocharger query - AlanGowdy
Does the turbocharger on my diesel car spin under exhaust gas pressure all the time the engine is running or just when the engine speed/gas pressure exceeds some value?
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Tue 29 Nov 2005 15:05
Turbocharger query - Alec
All the time.
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Tue 29 Nov 2005 15:55
Turbocharger query - John S
Yes, it's running all the time, but it isn't always pressurising the induction. Unless there is sufficient energy in the exhaust gas to spin the turbine suficiently fast and to impart extra energy to the intake, then it's not helping. The phenomenon of 'turbo lag' is just that effect. The lag is the time required before the exhaust gas reaches the energy level required to pressurise the induction. Once that point is reached the engine picks up much more strongly. Petrol engines are potentially worse in this respect as they use throttle governing, which inherently reduces gas flow through the engine, and hence have a significanrt efect on turbocharger performance.
JS
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Tue 29 Nov 2005 15:56
Turbocharger query - Roly93
All the time.

I took the outlet hose of mine with the engine at tickover, and it was surprising how much boost is there.
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Tue 29 Nov 2005 18:40
Turbocharger query - AlanGowdy
Thanks for the answers guys.

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