Jump to content
Forums Gone... but not forgotten!
Pontiac of the Month

2 Firebirdz's 1976 Trans Am

2024 November
of the Month

  • Rev up your passion for Pontiacs and join our vibrant community of enthusiasts!

    Whether you're a die-hard fan of classic muscle cars or you've got a soft spot for sleek modern models, you've found your home here at Forever Pontiac. Our community is dedicated to celebrating everything Pontiac, from the iconic GTO to the legendary Firebird and everything in between.

    Unlock access to expert advice, stunning photo galleries, engaging discussions, exclusive events, and more!

    Start your Pontiac journey with us today!

    Sign up now! 🏁

Car and Driver: Mazda’s Dynamic Pressure Turbo Explained


FeedBot

Recommended Posts

2016 Mazda CX-9 Signature

-
From the August 2016 issue
-

The Dynamic Pressure Turbo system fitted to the CX-9’s 2.5-liter engine combines elements of twin-scroll and variable-geometry turbos in one small package. Like a variable-geometry turbo, the CX-9 constrains exhaust flow at low rpm to accelerate the gases, which helps spool up the turbo. It produces the same result as putting your thumb over the end of a hose, but instead of doing so inside the turbine housing, as in a variable-geometry turbo, Mazda puts its “thumb over the hose” upstream. The valve body fits between the cylinder head and the turbocharger. Below 1620 rpm, the three valves are closed, forcing exhaust gas into the smaller passages above the three butterflies. The constricted path accelerates the gas into the turbine and improves the turbo’s low-rpm responsiveness. At 1620 rpm, the exhaust volume is great enough that the valves open and the turbo operates normally.

-

To manage the exhaust pulses as in a twin-scroll turbo, Mazda separates the engine’s waste gases into three distinct branches with a 4-3-1 exhaust manifold built into the head. The two inner cylinders blow their exhaust into a common runner, while the outer cylinders push their exhaust through individual pipes. Separating the gases has two effects. First: Scavenging uses the fast-moving exhaust gases from a cylinder beginning its exhaust stroke to help draw out the remaining low-pressure waste gas from the cylinder just starting the intake stroke in the adjacent passage. Second: By separating the exhaust into three path­ways, the turbocharger is hit with more evenly metered pulses, like a twin-scroll turbo. Those timed pulses improve responsiveness and help reduce turbo lag.

-

Mazda's Dynamic Pressure Turbo Explained

--hLvbEYLtY2M

Read Full Article

Link to comment
Share on other sites

Tired of these Ads? Register Today!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Tired of these Ads? Purchase Enhanced Membership today to remove them!
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.