Turbo question....

[dr_kno]

Hey, me and a friend are disagreeing about something, wondering if all you automotive guru's could shed some light on the subject:

Does a turbo spool up while a car is not in motion? Like, if you've got your car sitting in neutral, or just with the clutch in, and you rev the engine, will the turbo engage and produce boost?

[SirTony76]

yep

[Kompressor]

That's like asking if I press the accelerator will exhaust flow.

[barros777]

yes!!!!!!!!

[m3racer36]

but in most situations the car wil not produce boost if thats what you mean

[barros777]

????? waht do you mean with "will not produced boost"???

[barros777]

it will, but you dont use it, because it is on neutral!!!! but the boost is there!!!!

[Kompressor]

That's why some Rally drivers never let go of the gas, even when turning (But the clutch is depressed) = no turbo lag! But a horrible strain on your engine and turbo.

[Zor]

Originally posted by Kompressor
That's why some Rally drivers never let go of the gas, even when turning (But the clutch is depressed) = no turbo lag! But a horrible strain on your engine and turbo.

they do take there foot off the gas many of them have a misfiring system

[spoon]

MY TURBO GOES TO JUST BETWEEN VAC AND BOOST WHEN I REV IT HARD. SO YES, IT DOES SPOOL, BUT DOESNT REALLY BUILD BOOST.

[spoon]

sorry for the caps, I am at work. lol

[Scho]

It will spool and build a little boost depending on the turbo. A T66 will probably not build boost, because it will not spin as fast as a Garrett T25 or small turbo when there is no load or high volume of exhaust!

[Bimmer_boyIS]

The engine will usually need to be under load to produce boost, depending on the turbo. Have somebody with a turbo car rev it while parked, no blow off.

[dr_kno]

Originally posted by Kompressor
That's why some Rally drivers never let go of the gas, even when turning (But the clutch is depressed) = no turbo lag! But a horrible strain on your engine and turbo.

Actually, on "rally" cars (ie WRC), an anti-lag system is employed. When the driver lifts his foot from the gas pedal the ignition timing is altered with sometimes 40° or more of delay (retard) and the intake air and fuel supply mixture is made richer. The inlet butterfly is kept slightly open or an air injector is used to maintain air supply to the engine. This results in air/fuel mixture that keeps getting in the combustion chambers when the driver no longer accelerates. The ignition being delayed, the air/fuel mixture reaches the exhaust tubes mostly unburned. When the spark plug fires, the exhaust valve is starting to open due to the ignition delay mentioned above. Additionally, the exhaust temperature being extremely high, the unburned fuel explodes at the contact of the exhaust tubes. Luckily the turbo sits right there and the explosion keeps it turning (otherwise it would slow down since its intake, the exhaust gases, is cut-off). The effect is vastly lower response times.

[drunknmunky02]

dr_kno Hey, me and a friend are disagreeing about something, wondering if all you automotive guru's could shed some light on the subject:

Then this

Actually, on "rally" cars (ie WRC), an anti-lag system is employed. When the driver lifts his foot from the gas pedal the ignition timing is altered with sometimes 40° or more of delay (retard) and the intake air and fuel supply mixture is made richer. The inlet butterfly is kept slightly open or an air injector is used to maintain air supply to the engine. This results in air/fuel mixture that keeps getting in the combustion chambers when the driver no longer accelerates. The ignition being delayed, the air/fuel mixture reaches the exhaust tubes mostly unburned. When the spark plug fires, the exhaust valve is starting to open due to the ignition delay mentioned above. Additionally, the exhaust temperature being extremely high, the unburned fuel explodes at the contact of the exhaust tubes. Luckily the turbo sits right there and the explosion keeps it turning (otherwise it would slow down since its intake, the exhaust gases, is cut-off). The effect is vastly lower response times.