The TFSI / Quattro combination, which will power the lion's share of North American A4s, is a capable partner, with a newly fortified 252 horsepower and 273 pound - feet of torque (increases of 32 and 15, respectively) thanks to a number of tweaks including a redesigned cylinder head, variable valve lift, dual - mode fuel injection and an electronic
wastegate on the turbo.
A second way on controlling the vanes and boost, is to have a single canister on the turbo to control the vanes, and control the boost level with
a wastegate on the manifold.
Not exact matches
And while you don't hear much of the engine's cry (save the odd closed - throttle
wastegate whistle) from inside the car, anyone
on the outside — and within a half - mile radius — gets assaulted with a strange, compressed, turbine - ripping - air kind of sound.
The secret to this always -
on - the - alert attitude is a variable - vane
wastegate turbocharger.
I unloaded the car with 160k miles once the
wastegate actuator went
on the turbo.
By getting the engine management system to clamp the
wastegate down just a little longer
on the twin turbos, the GT V8 S now hits a peak of 521 hp at 6,000 rpm and shovels out torque of 502 lb - ft all the way from 1,700 to 5,000 rpm.
Inside, windows down, you can hear the
wastegates whoosh
on closed throttle.
The twin - scroll turbocharger integrated into the steel exhaust manifold and electric
wastegate control is extremely efficient —
on account of its compact construction and the presence of an indirect intercooler integrated into the intake manifold.
A new solution has also been implemented for the
wastegate valve (which stops boost pressure rising too steeply at high engine output) based
on an electronically controlled electric actuator developed by Continental.
The system's so - called rotary turbine control system directs exhaust flow to either of the two turbines, or a
wastegate, depending
on engine load.