http://paultan.org/archives/2007/12/...-turbocharger/



BorgWarner has developed a new integrated 2-stage turbocharger called the R2S system, which uses two differently sized turbochargers in a sequential arrangement.

The smaller of the two turbochargers is a smaller conventional unit that provides quick boost response at low engine speeds, while the larger turbocharger is of the Variable Turbine Geometry type, which uses variable vanes to suit a wider range of engine operating states.

 

now thats interesting....good info

 

those are the turbos off of the new ford powerstroke. they manufacture all of them in ashville north carolina and lucky me i know one of the engineers that works there and got to take a tour. you guys would creme your pants if you walked into the warehouse!!!!

but anyway, these turbos have been around for atleast a year or more. i also believe the VGT is the primary turbo because it can spool very quickly via moving the vanes to take advantage of the air. the other turbo is for top end.

 

We wouldn't be able to use this huh? I just can't picture it in the engine bay...

 

Got backpressure?

 

diesels guys have been running staged turbos for a long time, incorporating the variable turbine may be new though..

 

Yes they have, 200+ psi!!

 

so how well would this version of VGT hold up to rotary EGTS?

 

I was going to post pretty much the same thing. Turbos feeding other turbos isnt a new idea, just new to the street car world it appears. I knew it was only a matter of time.

 

Hmmmm price?

 

BorgWarner's R2S(R) regulated two-stage turbocharger system has been named a finalist for the prestigious 2008 Automotive News PACE Awards, recognized around the world as the industry symbol of innovation. It is the fourth BorgWarner (NYSE: BWA) innovation in four years to reach finalist status in the PACE Awards competition. BorgWarner also received PACE Awards in 2005 and 2007.

"As innovations advance with breathtaking speed, BorgWarner is at the forefront of the industry in providing technological solutions that enable our customers to improve engine performance, increase fuel economy and lower emissions," said Tim Manganello, BorgWarner Chairman and CEO. "We're proud of this recognition by the PACE judges, and pleased to be among this year's distinguished PACE finalists."

BorgWarner's R2S(R) regulated two-stage turbocharging system consists of two series-connected turbochargers: a smaller unit (referred to as the high- pressure turbocharger) and a larger unit (known as the low-pressure turbocharger). At low engine speeds, the smaller high-pressure turbocharger ensures spontaneous engine response without "turbo lag." With increasing engine speed, the larger low-pressure turbocharger gradually takes over more of the work, ensuring constantly increasing power and high output torque across a wide range of engine speeds. The combination allows car makers to offer low-fuel-consumption, efficient, downsized engines with the dynamic response and high peak output power of a larger engine, all with lower emissions. To date, BorgWarner's R2S(R) technology has been awarded six patents, with seven more pending.

The first large-scale passenger car production with an R2S(R) regulated two-stage turbocharging system was launched in 2005 on the BMW 535d and in 2006 on Ford F-Series Super-Duty(R) trucks.

Presented by Automotive News with Microsoft, SAP and the Transportation Research Center Inc. (TRC Inc.), the PACE Awards honor superior innovation, technological advancement and business performance among automotive suppliers. PACE stands for Premier Automotive Suppliers' Contribution to Excellence. This year marks the 14th annual award competition. BorgWarner's R2S(R) regulated two-stage turbocharging system is a finalist in the Product - Europe category, which recognizes innovations that were developed or first commercialized in Europe and have significant market impact that acts as "game changers" in the automotive industry. Winners are selected by an independent panel of judges and will be announced April 14, 2008, in Detroit.

BorgWarner won a 2007 PACE Award for its variable turbine geometry (VTG(TM)) gasoline turbocharger and 2005 PACE Award for its DualTronic(R) wet- clutch and control-system technology for a new-concept automated transmission. In addition, BorgWarner and Porsche were presented with two special PACE recognitions in 2007 for their successful collaboration on the Porsche 911 Turbo for the VTG(TM) turbocharger and all-wheel drive technology.

Auburn Hills, Michigan-based BorgWarner Inc. (NYSE: BWA) is a product leader in highly engineered components and systems for vehicle powertrain applications worldwide. The FORTUNE 500 company operates manufacturing and technical facilities in 64 locations in 17 countries. Customers include VW/Audi, Ford, General Motors, Toyota, Hyundai/Kia, Daimler, Renault/Nissan, Chrysler, Navistar International, Fiat, BMW, Honda, PSA, and Caterpillar. The Internet address for BorgWarner is: http://www.borgwarner.com.

SOURCE BorgWarner Inc.

http://www.borgwarner.com

 

Our product palette consists of turbochargers with variable turbine geometries for diesel and gasoline engines. Multistage, regulated 2-stage turbocharger (R2S™) systems represent real innovations. They include, for example, the regulated 2-stage turbocharger (R2S™) and the eBooster™ concept in which an electrically driven flow compressor provides the turbocharger support.

 

Regulated 2-stage turbocharging (R2S™)

The basic development goals for future combustion engines for automobile and commercial vehicle applications make more refined charging systems necessary. The design of such a charging system leads to conflicting goals in terms of the rated output of the engine on one hand and the transient response and the range of maximum torque on the other hand. You need a relatively large exhaust turbocharger to attain the nominal output point. The desire for a very high boost pressure even at low engine speeds means, however, that the turbine and the compressor need to be made much smaller. A combination of the two would be ideal.

To resolve this conflict, BorgWarner Turbo Systems has developed regulated 2-stage turbocharging. It meets the demands of an optimal design and allows for the continuously variable adaptation of the turbine and compressor sides of the system for each engine operating point.

With this newly developed charging system, BorgWarner Turbo Systems offers the engine manufacturer an additional extremely high-performing charging system for future engine generations that fulfills the highest requirements in terms of power, fuel consumption and emissions.

The regulated 2-stage turbocharger consists of two turbochargers of different sizes connected in series that utilize bypass regulation. The exhaust mass flow coming from the cylinder flows into the exhaust manifold first. Here it is possible to expand the entire exhaust mass flow using the high pressure turbine (HP) or to redirect some of the mass flow through a bypass to the low pressure turbine (LP). The entire exhaust mass flow is then utilized again by the low pressure turbine (LP).

The entire fresh air flow is first compressed by the low pressure stage. In the high pressure stage, it is compressed further and then the charging air is cooled. Due to the precompression process, the relatively small HP compressor can reach a high pressure level so that it can force the required amount of air to flow through the system.

At low engine speeds, i.e. when the exhaust mass flow rate is low, the bypass remains completely closed and the entire exhaust mass flow is expanded by the HP turbine. This results in a very quick and high boost pressure rise. As the engine speed increases, the job of expansion is continuously shifted to the LP turbine by increasing the cross-sectional area of the bypass accordingly.

Regulated two-stage turbocharging therefore allows for continuous adaptation on the turbine and compressor sides to the actual requirements of the operating engine.

The system can be regulated via pneumatic actuators that control the bypass valve in the same manner as when used in mass-produced turbochargers with swing valves. This makes it possible to model a compact charging system (when detailed knowledge of the complex system response is available) that fulfills the highest torque, response and power requirements while utilizing proven components.



Modern commercial vehicle turbochargers are subject to very high loads due to the wide range of applications they are used in. In many cases where there are extreme loads, a compressor impeller made of an aluminum alloy determines the service life of the turbocharger. In particular, material fatigue can result from extreme loads, especially when the loads are cyclical loads occurring at low frequencies. This phenomena is also known as low cycle fatigue (LCF).

Various measures can be taken to increase the service life. For example, the circumferential speed of the compressor impeller can be reduced by changing the aerodynamic design of the impeller or by controlling or reducing the charging pressure. High-strength aluminum, for example, that manufactured using the HIP technique, is often used to reduce variations in the strength of the material. The high-end solution using aluminum consists of milled compressor wheels which were also developed by BorgWarner Turbo Systems.

The increasing number of engine applications with high cyclical loads as well as the necessity to have higher charging pressures to remain within the stricter emission regulations have made an additional innovation step beyond the moulded aluminum compressor wheels necessary. In order to provide a customer with a technology that can withstand these loads and also ensure a service life that is just as long as it would be under standard conditions, BorgWarner Turbo Systems initiated a special development program.

The demands on the compressor impeller stated above make it necessary to use higher quality materials since the potential for improvement inherent in aluminum is just not sufficient anymore. The engineers at BorgWarner Turbo Systems decided to use a titanium alloy that is not only very hard, but also provides an excellent strength-to-thickness ratio.

With the titanium compressor impeller, BorgWarner Turbo Systems is now able to offer different compressor impeller technologies for special application requirements and special cyclical loads. In this manner the customer can select between cast or moulded aluminum compressor impellers or between cast or moulded titanium compressor wheels depending on the area of application.

One goal of a regulated turbine is to expand the usable flow rate range in practical applications while maintaining a high level of efficiency. To accomplish this, the turbine output is regulated by changing the inflow angle and inflow speed at the turbine wheel inlet. In the case of the VTG turbocharger from BorgWarner Turbo Systems this is achieved using guide vanes located in front of the turbine wheel.

When the guide vanes are in the closed position, the high circumferential components of the flow velocity and a steep enthalpy gradient lead to a high turbine output and therefore to a high charging pressure. When the guide vanes are in the fully open position, the turbine reaches its maximum flow rate and the velocity vector of the flow has a large centripetal component. The advantage of this type of output control over bypass control is that the entire exhaust mass flow is always directed through the turbine and can be converted to output. The guide vanes adjustments can be controlled by a series of different pneumatic or electrical regulators.

BorgWarner Turbo Systems currently offers various sizes of turbochargers with variable turbine geometries for diesel engines in automobiles and light commercial vehicles. The sizes range from 1.2 liters to 3.2 liters of displacement per turbocharger. This corresponds to an engine output range of 50 kW to 180 kW per turbocharger.

The demands placed on turbochargers with variable turbine geometries have steadily increased in the past several years. Just a while ago a per liter output of 35 kW was sufficient, but now the current state of the art demands 50-58 kW/l. A per liter output of up to 65 kW can be reached with improved turbocharger technology.

As a result of these higher demands, the exhaust temperatures and pressure conditions in the exhaust system increases. BorgWarner Turbo Systems currently offers turbochargers with variable turbine geometries for exhaust temperatures up to 850°C. In the future there will be turbochargers with VTGs for diesel engines with exhaust temperatures up to 900°C. Refinement of the VTG technology for use at even higher exhaust temperatures will expand the possible range of applications to include gasoline engines.

The mechanical demands placed on a VTG in a commercial vehicle are significantly higher than those placed on one in a passenger car since the rotary vanes also need to function as a highly efficient motor brake. This is necessary since future commercial vehicle engines will always have a lower displacement and the exhaust flaps used today at the end of the exhaust pipe will just not be enough anymore. Furthermore, the variable turbine geometry will be used to control exhaust gas recirculation, especially in modern commercial vehicle engines. When this is done, the pressure in front of the turbine is regulated by the VTG so that there is a sufficiently large pressure difference between the exhaust gas side and the fresh gas side after the compressor. Only then will the exhaust be drawn into the inlet duct through an exhaust gas recirculation valve.

BorgWarner Turbo Systems also offers a wide spectrum of VTG turbochargers that will meet all demands for use in commercial vehicle engines.

 

 

I thought of this years ago, I know my check's in the mail somewhere. I don't know why it's not here yet? Must have gotten lost in the mail

 

I know what you mean... Jamespond24 and I were dogged on big time a year ago when getting interest in a good variable geometry design turbo. All anyone would say is it will never stand rotary egt.

Now Borg Warner and Garrett are trying to buy the rights to the turbo design. If you like this idea, just wait. There will be one out soon enough that blows this away.

Josh

 

Josh, to date, only Borg Warner has a turbo (singular) that can withstand the high EGTs of a rotary. And it is NOT available to the consumer market; it's only for commercial use (manufacturers).

 

I read through that article and a couple things stick out. First of all, the heat thing. It says the turbo is rated to 850 C EGT's. that's like 1500 F. That will never work... on the highway in closed loop my T2 is at 1400-1450 F. It won't last too long on a rotary. Even the upcoming 900 C (1650 F) won't work. Any significant high revving backroads driving or track use has put my car over 1600 degrees before.

The other thing is the control mechanism. If you read closesly there are a number of actuators etc that will need to be controlled. I'm not sure if there's anything available that could handle that task (maybe Motec?) and even if you did, it probably wouldn't be worth the trouble.

It's still interesting technology though.

 

is this the same as a compound turbo system?

 

This one has vein system with only one internal moving part. The prototypes have all been done with Garrett turbos, but both Garrett and Borg Warner are in on bids for the technology. We've been doing testing for the past year on air cooled and water cooled Harley-Davidson's. Our recorded EGTs have only hit 1600F so far with no durability issues.

My TO4R is ready for a rebuild, so hopefully we will have some testing done on the 13B front too.

The heat concern in most designs is an issue. The Porsche guys seemed to find that out pretty quickly on the new 911's. This design has been tested on the new Porsche as well and it didn't have the melting/cracking problems.

Josh

 

Vs...??? They offer both electronic & pneumatic controlled VNT turbos, but again, all I could find was one type of turbo that was good for somewhat higher temps.

I was under the impression that much of this is already Borg Warner technology?

Nice! Who's "we" btw, if ya don't mind me askin? You work for Garrett or Borg?

Whatcha mean the Porsche guys seemed to find that out pretty quicky on the new 911's? Have they had any problems thus far? (Bracing himself for deja vu after Porsche's PCCB blunder lol).

 

Borg Warner is the front runner in this technology right now in terms of production. They are the ones who are on the diesel engines and the 911 Turbo. Garrett made a similar technology on one car in the 80's.

We is a small group of individuals: Blaylock-Turbo (the design was all their idea) and Cycle Connection (my employer we fabricate the turbo kit and do R&D on vehicle). Jamespond24 and I are doing the rotary engine testing on the side to try to bring something new to ther Rx7 community and car scene as a whole. He is modifying a GT40; I'm modifying a TO4R. I'm no Borg Warner/Garrett employee. Just a guy who'd love to see these work on gas (rotary!) engines.

The only problems they have had on the 911's is when increasing boost and EGT's the vanes tend to melt/hairline crack. Borg Warner even used special material to combat that specifically, but they get too hot in not so stock applications. This is the same problem that has been around with this design on gasoline applications since the 80's. The current turbos have many small vanes and moving parts. Here is a pic of how the current Borg Warner setup looks:

Low RPM altered gas flow to small AR


High RPM altered gas flow to bigger AR by moving vane angle


The Blaylock setup uses only one moving vane on the hot side. Pnumatic solenoids were used for control at first. Electronic solenoids are being tested now before manufacturing. We've modified the turbine housing only on existing turbochargers so far. The bikes we've done have nearly no lag and can be tuned via solenoids to idle in boost if you want (minimal) and be at full boost within a second or so. These are smaller turbos than what are on cars, but the ideas are the same.

I'd expect to see Garrett or Borg Warner pumping out the Blaylock style design here in a couple of years. I may be wrong. VVT/VGT/VTG turbos have been a great advancement for the diesel industry. Now we have a design that works on (proven on piston) gasoline engines. The new design compared to ball-bearing has quicker boost response, lower cost, and is more reliable (using journal bearings).

James and I will report back once the Rx7's are fitted and they get some miles on them.

Check out http://www.blaylock-turbo.com/ to see videos of the turbos installed. You can hear the turbo spooling at idle on the Softail (Warning: I live in the mid west. The guy has a ridiculous accent in the video.). The VROD is doing a fly by so you can't tell anything. Watch the boost gauge in the Dodge is boosting 3lbs at idle then 40ish within a second with normal acceleration (not mashing it) from a stop.

Josh

 

wrongo. Gattett vnt turbos are on vw tdi engines and work well until they get sooted up from diesel. I think they have been on there since some where around 00.

 

Video of the FOrd unit in super duty trucks

http://www.fordvehicles.com/thetruthabouttrucks/

click on engine>powerstroke v8