The "mono" Turbo is going to be introduced in Europe too, also for the 135i and other BMW models. While BMW points out the weight reduction and environmental advantages, the truth is that they wanted to save cost. The twin turbo engine was just too expensive compared to the mono turbo engine.
RC (Germany) - Rennteam Editor 997 Turbo, BMW X5 M (03/2010), BMW M3 Cab DKG, Mini Cooper S JCW
Almost all engines (from 320d to 335i) will get a little power gain, but I didn't talk in details, so Im not sure if N55 will replace N54.. Press release will be in Sunday, so in a few days everything will be official..
I heard that Z4 sDrive35i will get N55 engine, while sDrive35is got N54 engine. If this information is true, then Z4 will be offered with N54 and N55 engines.
Power numbers means nothing on paper, unless it's supplied with the HP/Torque curve and rpm numbers.
The twin-turbo version is a fantastic engine simply because of the lack of lag from low rpm and the super low-end grunt.
The new single turbo engine may match the numbers, but if the torque peak is higher up in the rpm, or does not offer the same or more torque at lower revs, or have more lag than the twin-turbo, then the engine is not superior. Well maybe only in fuel economy.
artur777:
there will be two modifications
standard with single turbo
sport with bi-turbo
I'm not sure what you mean by that. I rather think that BMW wants to keep the bi-turbo engines for M company, so I suppose that the current 4.4 i bi-turbo charged V8 in its "base" for with 408 HP gets a mono turbo too. Just a speculation though...
I'm curious about the bi-turbo Diesel engines: do they get a mono turbo too ?
RC (Germany) - Rennteam Editor 997 Turbo, BMW X5 M (03/2010), BMW M3 Cab DKG, Mini Cooper S JCW
Whoopsy:
Power numbers means nothing on paper, unless it's supplied with the HP/Torque curve and rpm numbers.
The twin-turbo version is a fantastic engine simply because of the lack of lag from low rpm and the super low-end grunt.
The new single turbo engine may match the numbers, but if the torque peak is higher up in the rpm, or does not offer the same or more torque at lower revs, or have more lag than the twin-turbo, then the engine is not superior. Well maybe only in fuel economy.
BMW seems to think so, from the pressrelease:
"The new six-cylinder (N55 designation) develops maximum output of 300 hp at 5,800 rpm, with peak torque of 300 lb-ft available all the way from 1,200–5,000 rpm. This is the same level of performance as the current 3.0-liter twin-turbo six-cylinder but with the innovation of twin-scroll technology and the integration of VALVETRONIC throttle-less intake technology, this new engine promises even better throttle response and even more fuel efficiency. Thanks to VALVETRONIC, VANOS, and the twin-scroll turbocharger housing, peak torque is reached 100rpm earlier than with the previous engine, and engine boost response is improved across the entire engine speed range"
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I'm curious about the bi-turbo Diesel engines: do they get a mono turbo too ?
Well, now they're talking about a tri-turbo engine
"Another day, another rumor in the BMW world. The long time rumored tri-turbo engine will make its debut at the Frankfurt Auto Show in 2011, and will power two new X5 and X6 models, in the addition to the xDrive40d announced yesterday.
The BMW X5 xDrive45d and X6 xDrive45d are to be considered Performance Diesel vehicles with the engine outputting 354 horsepower.
This new engine will carry the EfficientDynamics badge by incorporating technologies like Start-Stop system and Brake Energy Regeneration (KERS). It will be geared towards the European market in need for a top X5 model.
BMW X5 Performance Diesel has less pronounced wheel arches that the ones seen on the new BMW X5 M. The wheels give the car very sporting and powerful appearance. The aerodynamic performance package follows the design of the X5 M, but the central intake is smaller with the intakes for the brakes less open mouthed and a colored bar across.
Same source, someone close to BMW, speaks of subtle spoilers for air flow at the leading edge of the bumper. The rear of the car features two larger and more exposed performance exhaust pipes which will be incorporated in the upcoming facelift of the X5.
The tri-turbo engine will be first available in the X5 models and the X6 at a later date. BMW plans to introduce the engine within key models such as the next 5 Series , 7 Series and eventually the additional 5er and 6er variants."
www.bmwblog.com/2010/01/13/rumor-bmw-to-launch-tri-turbo-diesel-x5-45d-and-x6-45d-next-year/
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temm:
BMW seems to think so, from the pressrelease:
"The new six-cylinder (N55 designation) develops maximum output of 300 hp at 5,800 rpm, with peak torque of 300 lb-ft available all the way from 1,200–5,000 rpm. This is the same level of performance as the current 3.0-liter twin-turbo six-cylinder but with the innovation of twin-scroll technology and the integration of VALVETRONIC throttle-less intake technology, this new engine promises even better throttle response and even more fuel efficiency. Thanks to VALVETRONIC, VANOS, and the twin-scroll turbocharger housing, peak torque is reached 100rpm earlier than with the previous engine, and engine boost response is improved across the entire engine speed range"
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I missed the press release, but the numbers does looks good on paper. I wonder how BMW did it. That single turbo surely is bigger than the 2 before, and how did BMW managed lag.
I thought you'd never ask
Here's a detailed explanation on how twin-scroll works, pretty cool stuff, knock yourself out:
www.bmwblog.com/2010/01/02/twin-scroll-turbo-system-design-explained/
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You can make ANY technology sound better than the previous one. While I trust BMW regarding performance and fuel consumption, I still think that the main reason for developing this engine was...production cost.
RC (Germany) - Rennteam Editor 997 Turbo, BMW X5 M (03/2010), BMW M3 Cab DKG, Mini Cooper S JCW
Had a brief glace at that.
So BMW basically combined 2 smaller turbos into one housing. Good for lag control and throttle response.
I am however not buying into the high end benefits, common accepted logic on turbos is that the bigger the turbo, the higher the maximum boost it can provide, so with the twin screw turbos, the maximum pressure ceiling would be lower than a single turbine one. But that's a moot point for BMW as OEM as they won't go near theoretical limit for obvious reasons.
With a lower ceiling BMW can save cost on not overbuilding the engine, components can be made less robust.
Aftermarket may not like the change but BMW's accountants must be loving it.
It should also be noted that the higher powered versions (335is, Z4 35is) will retain the twin turbo engine, boosted at 335 BHP. So, BMW keeps the better engine for the higher powered models and serves a cheaper engine to the rest. At any rate, two turbos for a specific output of 100 BHP/litre was an overkill and BMW realised that it could do the same with one single turbo (cost reduction).
Whoopsy:
So BMW basically combined 2 smaller turbos into one housing. Good for lag control and throttle response.
The Twin-scroll turbochargers combine two exhaust lines into one housing. Depending on the firing order, the exhaust pulsation of the respective cylinders interfere with each other. So separating the (two) oppositional pulsating exhaust gases into individual turbine inlets. That leads to faster and earlier (lower RPM) response of the turbocharger and, in conjunction with adjacent modifications (valve and ignition timing) to improved efficiency.
Faster engine resonse and higher efficiency are the reason for both systems from BMW, twin-turbo (N54) and twin-scroll (N55), but the later does so with a simpler and cheaper system. The reason why twin-scroll turbochargers (re-)appear on the market in recent years is, just as on Porsche´s VTG, is the material requisition due to high exhaust temperatures on a gasoline engine (up to 960 C°) . From my knowledge, the N55 engine will be the first twin-scroll system combined with six-cylinders attached to one turbocharger. All remaining ones (BMW/PSA 1.6, BMW 4.4, Opel/GM 2.0) combine one turbocharger with four cylinders (in total or per cylinder bank).
So, after all, I do not buy into the complaints about cost efficiency, it does make the engine simpler without innate disadvantages if I recall the issues some of the more complex systems, such as Volkswagen´s TSI (turbocharger-supercharger combination) can have.
The X5 M for example uses a bi-turbo twin-scroll turbocharger engine. Sizing down to one charger only is surely not because it is better. It is more cost efficient and it also keeps tuners for messing around with too much power output.
RC (Germany) - Rennteam Editor 997 Turbo, BMW X5 M (03/2010), BMW M3 Cab DKG, Mini Cooper S JCW
RC:
The X5 M for example uses a bi-turbo twin-scroll turbocharger engine. Sizing down to one charger only is surely not because it is better. It is more cost efficient and it also keeps tuners for messing around with too much power output.
The twin-turbo 4.4 V8 uses a unique (and patented) layout to consolidate the exhaust gases from both cylinder banks into two twin-scroll chargers with the above mentioned advantages. That would not come into effect with only one turbocharger since the charger itself would become bigger (and respond slower).
The inline-4 and inline-6 (N55) models have lower displacement and number of cylinders so the use of a second turbocharger is negligble. Of course, one could set up two twin-scroll chargers in a layout as on the N54 variant but since both concepts in itself significantly reduce turbolag, what would be the advantage of them combined? They still come at the expense of higher manufacturing, maintenance and weight.
I almost forgot, all the pics and the pressrelease:
http://www.e90post.com/forums/showthread.php?t=341511
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This is really funny and I know you guys won't believe this but my friend who showed up in his camoed 5 series a couple of months ago, just came by this evening in a camoflaged BMW 3 series Coupe. Camoflage was the usual black/white only back and front. I couldn't take photos because that damn iPhone 3GS doesn't have a flash and it was too dark, it couldn't focus. First when I saw it, I thought it is a 5 series Coupe but when I looked closer...
RC (Germany) - Rennteam Editor 997 Turbo, BMW X5 M (03/2010), BMW M3 Cab DKG, Mini Cooper S JCW
New taillights looks great, but IMO front is step backward. Pre LCI front looks better...
RC:
Any new X5 LCI infos ?
German dealers already have it but as much as I begged, my dealer wouldn't want me to copy it.
Changes regarding your car will be very minor - If I remember right, only new taillights (same shape, different LED graphics - similar to E92/E93 LCI), and white LED angel eyes with LED turn indicators.