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Production and testing of the V8 4.4 liter Twin-Scroll from BMW X5M

Videos | September 25th, 2010 by 5
M twin-scroll

In 2009, BMW unveiled their first M car powered by a turbocharged engine. The twins BMW X5M and X6M launched into the market in a …

In 2009, BMW unveiled their first M car powered by a turbocharged engine. The twins BMW X5M and X6M launched into the market in a moment less favorable for a vehicle of their caliber, both from a pricing perspective and fuel efficiency.

The M SAV twins came equipped with the latest engine coming from M Division: a V8 4.4 liter twin-scroll engine delivering 555 horsepower at 6,000 rpm and 500 lb-ft of torque from 1,500 to 5,650 rpm. The engine was developed under the internal code S63.

The engine uses the twin-scroll twin turbo technology with High Precision Direct Injection. By positioning the twin-scroll turbochargers together with the catalytic converters in the “V” section between the cylinders, it minimizes the turbo lag and offers better fuel efficiency.

M twin-scroll

A video released by BMW gives us more insight into the production and testing of this new powerplant, so let’s have a look.

Current Spec for X5/6M:
Cylinders/valves 8/4
Capacity in ccm 4395 / Biturbo
Stroke/bore in mm 88.3/89.0
Max. output in kW/bhp at 1/min 408 (555)/6000
Max. torque in Nm at 1/min 680/3400

  • http://www.facebook.com/profile.php?id=100000477069969 Hugo Becker

    The term ‘split exhaust’ refers to what in an NA engine would be termed a ‘bundle-of-snakes’ exhaust (or sometimes, when the exhaust ports are on the outside of the block a ‘180 degree’ exhaust). It basically takes the output of a split plane crank and tunes the exhaust as if it were coming from a single plane crank. There are benefits for spooling the turbo by doing that and it’s unique to the M turbo V8 engines built by BMW.

  • Laszlo

    yes its impressive but what about heat ? The turbo’s are right in the middle and surrounded but the exhaust. Isn’t it gets a little too hot in there ?
    I’m sure that a good cooling can help but why not put the exh side to the outside like before ? Turbo lag is still present and economy.. well who cares in a 4.4l 555HP engine if it uses 2dl less gas for 100km. It won’t save the planet for sure.

    I drove the X6 and it is amazing but still I don’t get the real benefit of stuffing the hot stuff into the smallest tightest space.

    • wazon8

      Don’t worry, BMW solved heating problem somehow, since there is no complaint on cooling in these engines. The reason why this engine is construed this way is to reduce turbo lag, the first step was to put turbos and exhaust inside V and another step (in M engines) was to change ingnition order. The solution is so good that BMW even patented it. Did you drive 4.4 TT M refined engine? The turbo lag is innoticable in it. And – supposing contra facts – even if it was, it would be greater without this solution. You can search an extensive article about what change in M refined 4.4 TT and you will learn that’s very different engine from 4.4 TT applied in 50i. Just search it on this blog, it’s really nice and explain a lot about benefits of putting turbos inside V.

  • Giom

    So short…? I was hoping for a nice mini documentary on this engine… and at a nice large format. C’mon BMW, give us a nice HQ flick!

  • Kyle Leclair

    From what I understand, did the video say they endurance test the engine at full throttle for 400 straight hours? That seems almost unbelievable. Does anyone have any insight to this?

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