Turbochargers and Superchargers

[empy]

VATN - Variable Area Turbine something. Not sure how it works but supposedly this type of turbo allows smoother/more consistent power delivery from low to high RPM...

[pajerokid]

Is the VATN different from a VG Turbo like in the thai spec strada? (Variable Geometry)

[Auto_Xer]

It's probably the same.
You can tell the difference between a VATN turbine & standard turbine by where the actuator for the waste gate is located.

On the Nissan, the actuator is in the middle of the compressor & turbine side of the turbo, oriented perpendicular to the turbine shaft axis.
On most standard turbine the awastegate actuator is parallel to the turbine shaft axis.

VATN-variable area turbine nozzle.
Instead of a wastegate the are vanes which move & change the effective size of the turbine.
When there is low or little exhaust pressure the vanes are closer/almost touching the turbine blades.
This enables the turbine to spin/spool faster & build boost at a lower rpm.
As exhuast gas pressure increases, the vanes move away from the turbine making it act like a "bigger" turbine, slowing down or maintaining the turbine speed & regulating boost.
In effect the VATN acts like a wastegate but with the added benefit of quick spool & boost at a relatively low rpm.

I only wish I had a pic available to make it easier to explain.

Trivia bit, the VATN has been around for almost if not more than 10 years, I first encountered it back in 93-94.
At the time it was at least twice the cost of a standard turbo.
Due to it cost very few turbo system developers supported it.
Back then, it was found mostly on modded motorcycles.
A few years ago, Garrett(either bought the rights to it or the patent had expired, I don't know which) introduced a VATN turbo into their product line.

Of the few auto turbo systems makers that did support it, one stands out in my mind.
On the Bell Eng'g turbo system for the 1.6 Miata, it made 6PSI of boost at 2000RPM with boost maxxing out on the system at 8psi.
At that setting, the BEGI turbo system made 250HP(iirc) up quite a bit from the Miata's then stock output of 110-120hp range.

[Karding]

Originally posted by splerdu
Another form of Anti-Lag puts a dedicated injector and sparkplug in the manifold, so the turbine can be spun for even longer off-throttle periods. Problem with anti-lag is the wear on the turbine itself. You'll have to treat your car like WRC, and rebuild the turbine every 500-1000km.

...and maybe the reason why Subaru has chosen to utilize the Twin-Scroll Turbo for the USDM STi, is to save the daily driven car some hassles or money for getting a dedicated injector as one way of preventing or minimizing the lag. the twin scroll is just a more advanced tubine housing design that helps to enhance exhaust gass energy utilization while minimizing ehxaust manifold backpressure and hence potential for reversion.


quote from garret: Twin-Scroll
By utilizing dual openings, or volutes, into the turbocharger's turbine housing, exhaust energy is optimized which results in better engine performance at low speeds, decreased backpressure at high speeds, and significant gains in fuel economy.

di ba the cooler the air, the more dense it becomes kaya more air molecules ang magkakasya sa combustion chamber kung malamig ang hangin. if what you're saying is true, e di wala rin silbi ang mga cold air intakes?

advisable on NA car but CAI is known to lean out your A/F for F/I engine. Having said that, most of us, WRX owners, uses a SRI with silicone intake arm.

[Sparks4agze]

Do you have any idea why when the supercharger of my 4agze lights up (works), my exhaust sounds mess like a gutling gun then the rpm decreases. Therefore, the power is wasted.

Initial diagnosis is the fuel pump.