digplanet beta 1: Athena
Share digplanet:

Agriculture

Applied sciences

Arts

Belief

Business

Chronology

Culture

Education

Environment

Geography

Health

History

Humanities

Language

Law

Life

Mathematics

Nature

People

Politics

Science

Society

Technology

Twin-turbo or biturbo refers to a turbocharged engine in which two turbochargers compress the intake charge. More specifically called "parallel twin-turbos". Other kinds of turbocharging include sequential turbocharging, and staged turbocharging. The latter is used in diesel automobile racing applications.

Parallel twin-turbo[edit]

3.5 Ford EcoBoost engine (Twin Turbo)

Paralleled twin-turbo refers to the turbocharger configuration in which two identical turbochargers function simultaneously, splitting the turbocharging duties equally. Each turbocharger is driven by half of the engine's spent exhaust energy. In most applications, the compressed air from both turbos is combined in a common intake manifold and sent to the individual cylinders. Usually, each turbocharger is mounted to its own individual exhaust/turbo manifold, but on inline-type engines both turbochargers can be mounted to a single turbo manifold. Parallel twin turbos applied to V-shaped engines are usually mounted with one turbo assigned to each cylinder bank, providing packaging symmetry and simplifying plumbing over a single turbo setup. When used on inline engines, parallel twin turbos are commonly applied with two smaller turbos, which can provide similar performance with less turbo lag than a single larger turbo. Some examples of parallel twin-turbo inline engines are Nissan's RB26DETT, BMW's N54 and Volvo's B6284T and B6294T. Some examples of V formation engines with parallel twin-turbos include Mitsubishi's 6A12TT and 6G72TT; Nissan's VG30DETT and VR38DETT; and Audi's 1997-2002 S4 (B5), 1997-2005 A6, and 2003-2004 RS6.

While a parallel twin-turbo set-up theoretically has less turbo lag than a single turbocharger set up, this is not always the case due to many factors.[citation needed] Marginally reduced combined inertial resistance,[citation needed] simplified exhaust plumbing, and the simultaneous spooling of both turbos means that there can still be a noticeable bit of lag, especially in high-flow turbo/high boost applications. Some ways to counter this are to use a light pressure set up with smaller turbos, where the turbos are designed to output less boost but spool earlier. While this setup sacrifices some top end power, it still has less lag than a similar engine with a single turbo set up making the same power. Another system would be the use of variable geometry turbochargers. This system changes the angle of the guide vanes depending on the exhaust pressure, giving the system excellent power throughout the rev range. Once used mainly in turbocharged diesel engines, Chrysler was the first to use it in mass-production gasoline-powered vehicles with the Shelby CSX, debuted in 1989.

It is possible to use parallel operation with more than two turbochargers. Two such examples are the Bugatti EB110 and Bugatti Veyron, both of which run four turbochargers in parallel. The EB110 runs 4 turbos on a 3.5 litre V12 engine, producing 542 hp (404 kW) at 8000 rpm, while the Veyron uses an 8.0 litre 16 cylinder engine to generate 1,001 PS (736 kW; 987 hp).

Sequential turbos[edit]

BMW 3 Series Diesel turbo setup (Sequential turbo)

Sequential turbos refer to a set-up in which the motor utilizes one turbocharger for lower engine speeds, and a second or both turbochargers at higher engine speeds. Typically, larger high-flow turbochargers are not as efficient at low RPM, resulting in lower intake manifold pressures under these conditions. On the other hand, smaller turbos spool up quickly at low RPM but cannot supply enough air at higher engine speed. During low to mid engine speeds, when available spent exhaust energy is minimal, only one relatively small turbocharger (called the primary turbocharger) is active. During this period, all of the engine's exhaust energy is directed to the primary turbocharger only, providing the small turbo's benefits of a lower boost threshold, minimal turbo lag, and increased power output at low engine speeds. As RPM increases, the secondary turbocharger is partially activated in order to pre-spool prior to its full utilization. Once a preset engine speed or boost pressure is attained, valves controlling compressor and turbine flow through the secondary turbocharger are opened completely. (The primary turbocharger is deactivated at this point in some applications.) In this way a full twin-turbocharger setup provides the benefits associated with a large turbo, including maximum power output, without the disadvantage of increased turbo lag.

Sequential turbocharger systems provide a way to decrease turbo lag without compromising ultimate boost output and engine power. Perhaps the most noteworthy application of this system is the fourth-generation Toyota Supra (1993-1998), which is generally regarded as having the most reliable sequential turbo system yet fitted to a production automobile, with a reported failure rate of less than 1% as of 2011.[citation needed] Other examples of cars with a sequential twin-turbo setup include the 1986-1988 Porsche 959, the 1990-1995 Eunos Cosmo JC, 1992-2002 Mazda RX-7 FD3S Turbo (13B-REW engine), and the 1994-2005 JDM Subaru Legacy GT, GT-B & B4 RSK (EJ20TT engine).

Staged turbocharging[edit]

A sequential turb can also yle to a system where the output pressure must be greater than can be provided by a single turbo, commonly called a staged twin turbo system. In this case, multiple similarly sized turbochargers are used in sequence, but both operate constantly. The first turbo boosts pressure as much as possible (for example to three times the intake pressure). Subsequent turbos take the charge from the previous stage and compresses it further (for example to an three times intake pressure, for a total boost of nine times atmospheric pressure). This configuration is commonly found on piston engine aircraft which usually do not need to rapidly raise and lower engine speed (and thus where turbo lag is not a primary design consideration), and where the intake pressure is quite low due to low atmospheric pressure at altitude, requiring a very high pressure ratio. High-performance diesel engines also sometimes use this configuration, since diesel engines do not suffer from pre-ignition issues and can use significantly higher boost pressure than Otto cycle engines .

Advantages in Diesel emissions[edit]

While spark ignition engines have fallen out of favor of the sequential turbo design,[citation needed] many diesel companies now make engines with sequential turbos in order to reduce emissions. Caterpillar Inc. ACERT engines utilize sequential turbos as well as International on some of their newest engines.

See also[edit]

External links[edit]


Original courtesy of Wikipedia: http://en.wikipedia.org/wiki/Twin-turbo — Please support Wikipedia.
This page uses Creative Commons Licensed content from Wikipedia. A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia.
1000000 videos foundNext > 

https://youtube.com/devicesupport

4000hp pair of TWIN TURBO Lambos!

This pair of OB Prestige Auto / Heffner Performance Lambos quickly caught our eye at TEXAS INVITATIONAL, not only are they "loud" looking, but they are LOUD and they sure do pack a punch! ...

NASTY 840hp Twin Turbo SRT-8 Jeep

This 1200hp Capable Jeep sure was impressing the hell out of us at the Shift S3ctor Pikes Peak Airstrip Attack! The 440ci 7.3L Hemi equipped SRT8 Jeep had a nice set of Twin 62mm Turbos under...

1400HP Twin Turbo Lamborghini Gallardo - EPIC accelerations and sounds!!

Jamboolio records an insane 2004 twin-turbo Lamborghini Gallardo by SK Performance and KKD Motorsport, Finnish tuning companys, producing 1359 horsepower! Here's some crazy fast ...

Twin Turbo 370z Review!- Boosted,Blue, and Lady Driven!

For this video, the lovely Paige Baker let me hop in the driver seat of her beautiful twin turbo 370z that is easily one of the best looking cars I've ever seen in person. An example of a build...

17 Year Old’s INSANE Twin Turbo Camaro

Alex Taylor - The YOUNGEST competitor to ever enter Drag Week (16 years old at Drag Week 2013) - has returned this year with TWIN TURBOS on her Camaro! This thing is bad...and we were ...

6,000hp of Twin Turbo ’57 Chevys - THE EVIL TWINS

1000 MILES OF DRIVING and averaging in the SIXES over 5 days - Drag Week 2014 CHAMPION Jeff Lutz Sr put on one hell of a show with his son Jeff Lutz Jr this year as they each piloted two of...

3000+ hp Twin Turbo CADILLAC vs 3000+ hp Twin Turbo CORVETTE

Scott Lowery in his Moran powered Twin Turbo Cadillac vs Mark Woodruff in his Proline powered Twin Turbo Corvette from the Throwdown in T-Town at Tulsa Raceway Park. Full event DVD available...

Chevy Apache Twin Turbos

Caleb's twin turboed apache CHECK OUT " COOLASSPARTS.COM" Hales Speed Shop https://www.facebook.com/pages/Hales-Speed-Shop/350183965091067 Check out our CANNON video below ...

TX2K15 - Twin Turbo BOSS gets HUSTLED!

Our last video from TX2K15! Street racing has always been "run what you brung" type deal, and TX2K is no different. This video serves as prime example of why you should never trust anyone that...

1000000 videos foundNext > 

49899 news items

autoevolution

autoevolution
Mon, 20 Apr 2015 20:55:33 -0700

To be honest, we were kind of disappointed with the new McLaren 540C. They may have made one price cut too many in their chase for new customers. No such problems with the Ferrari 488 GTB, as the latest Prancing Horse is better in every way than its ...

autoevolution

autoevolution
Sun, 19 Apr 2015 01:34:41 -0700

It seems we won't have to wait until Monday morning to see what the GLC Coupe concept car looks like. That's because Mercedes has taken the virtual wraps off the car hours before the show, so that we can have a good look at what they've done.

Digital Trends

Digital Trends
Wed, 08 Apr 2015 06:12:24 -0700

If the latest rumor is true, Ferrari might jump in the mix and knock it clean off. According to a tweet by Motor Trend writer Jonny Lieberman, Ferrari has a twin-turbo six-cylinder car in the works for 2019. Priced around $180,000, roughly $20,000 less ...

Car and Driver (blog)

Car and Driver (blog)
Tue, 07 Apr 2015 07:48:45 -0700

Could the latest casualty of an industry-wide replacement-for-displacement spree be Hyundai's 5.0-liter Tau V-8? It's the 420-horse powerhouse that hustles the Genesis sedan to 60 mph in five seconds flat. We hope not, but the fact that Hyundai is ...

Motor Authority

Motor Authority
Tue, 07 Apr 2015 14:18:07 -0700

That's why you're looking at renderings of what should prove to be an insane-o beast of a sedan rather than the actual thing, based on the 2016 Cadillac CTS-V. John Hennessey and his team are clearly eager to get their wrenching mitts on the car ...

Hot Rod Network

Hot Rod Network
Thu, 02 Apr 2015 15:19:59 -0700

On April 1, 2015 (April Fools' Day), we published a “spy photo” of an upcoming sixth-generation Camaro performance variant. HOT ROD Staff Editor Thom Taylor started with a photo he took of a Lingenfelter-supercharged, 625hp 1LE from a recent HOT ROD ...

Edmunds.com

Edmunds.com
Mon, 23 Mar 2015 07:58:44 -0700

DETROIT — An all-new 3.0-liter twin-turbocharged V6 engine will be one of the powertrain options available to buyers of the 2016 Cadillac CT6 flagship sedan, GM announced late last week. The new CT6 debuts on March 31 at the 2015 New York Auto ...

eGMCarTech

eGMCarTech
Thu, 16 Apr 2015 18:18:45 -0700

Some big changes are amounting for the launch of the second generation Hyundai Genesis Coupe. It didn't exactly hit success with strides, provided it was a niche vehicle aimed at a very specific market, dominated otherwise by the Nissan 370Z. That said ...
Loading

Oops, we seem to be having trouble contacting Twitter

Support Wikipedia

A portion of the proceeds from advertising on Digplanet goes to supporting Wikipedia. Please add your support for Wikipedia!

Searchlight Group

Digplanet also receives support from Searchlight Group. Visit Searchlight