jeff_is_sexy
12-24-2006, 02:52 PM
Does anyone know the details on it? Are there any specific disadvantages to a system like they have?
From what I understand, it uses a valve that closes when exhaust flow is lower (i.e. at lower RPM). As the valve closes the exhaust velocity increases, therefore eliminating lag.
I know this doesn't really apply to a V8 engine since lag is virtually nonexistant in a larger engine, but I thought I'd post up that info in case anyone was interested.
engineermike
12-25-2006, 12:57 AM
Looks like a variable A/R turbine, basically.
As always, when you add more components, the liklihood of them all working properly and without failing decreases.
I still like my theory. Build an engine that's stout off-boost (388 LT4, AFR210's, 224/236 cam). That way, it's not a terd before spool-up (T76).
Bayer-Z28
12-25-2006, 12:18 PM
I believe Banks came up w/ a similar design for the Power Stroke Diesel. And the Duramax I believe.
Defenetly IMPRESSIVE to say the least! By the time I have the money for a turbo, I hop I can get something like it.
http://www.bankspower.com/im_DieselPower_fall05.cfm
The stock Cummins comes with a non-variable turbo, so Banks decided to bolt on the company’s new ShapeShifter variable-nozzle turbo charger. It’s a Banks/Garrett turbo with adjustable vanes that change the effective size of the turbine relative to airflow. In other words, it lets the turbo act like a smaller unit for rapid acceleration and also as a large turbo for improved top-end power. As a result, the Dodge boasts the most power of the three trucks shown here, with 500 horses and 1,000 lb-ft of torque produced at the flywheel.
cjmatt
12-25-2006, 08:58 PM
theyve been around for a while...Dodge used them in the shelby csx back in 1989 and they make good power, but generally theyve only been used on diesels as gasoline engines have egts alot higher and it basically kills the adjustable vanes in the turbos
engineermike
12-25-2006, 10:25 PM
There's a difference between a variable flow turbo, and a variable vane turbo.
The variable flow modifies the single passage going into the turbine wheel to increase or decrease the velocity of the gas. Just like have a .81 A/R for spool, but a .96 on top end.
The variable vane (as used by shelby, Ford deisels, and Aerocharger) uses vanes to direct the gas tangentially or radially at the turbine wheel. This basically controls boost so a wastegate is not needed.
Mike