it prob has some bokoo compression! 
bmw twin scroll twin turbo
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bmw twin scroll twin turbo Well, seems someone finally did it, I never expected BMW to do it though, but what a brilliant design for those who read about it, beginning with a V engine and ONE exhaust manifold.
It would be very interesting to see more and more people come up with a twin scroll twin turbo designs which BMW has proven to be very competitive.
A few facts:
full boost or 1.5bar of boost all the way from 1500rpms to about 5700, and drops a tiny bit after that. With torque dropping after 5700 and max power at 6000, looks like an indirect way to lower the max HP number on paper, while making equaivalent power of a ~600HP vehicle.
Torque is LITERALLY flat from 1.5k to 5.7k and as a result, power increases linearly to redline, even though the car has absolutely no problems with power delivery through its 4x4 system.
NOT AN LS, but something very interesting to share, hope we could argue this design
It would be very interesting to see more and more people come up with a twin scroll twin turbo designs which BMW has proven to be very competitive.
A few facts:
Both the new BMW X6 M and BMW X5 M, set to debut this week at the New York Auto Show, are powered by a newly-developed 4.4-liter V8 M engine delivering 555 HP at 6,000 rpm and 500 lb-ft o' torque from 1,500 to 5,650 rpm. The new M engine is the first with a pulse-tuned exhaust manifold encompassing both rows of cylinders combined with high-performance twin-scroll twin turbo technology.
Torque is LITERALLY flat from 1.5k to 5.7k and as a result, power increases linearly to redline, even though the car has absolutely no problems with power delivery through its 4x4 system.
NOT AN LS, but something very interesting to share, hope we could argue this design
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placing the turbos and the two manifolds next to each other where the intake manifold was supposed to be must keep the heat in very nicely. witch will help the spool times.
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So I'm guessing that essentially their exhaust exits where we have an intake manifold, and their intake manifolds are now twin intakes on the outside of the block.
Different for sure. Has any other v-block engine had this setup?
Different for sure. Has any other v-block engine had this setup?
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That is an awesome piece of engineering right there!
I am very intrigued by the dual twin scroll turbos. Im guessing that they use using 2 cylinders per "scroll" and using pairing them as close to 180 as possible to keep exhaust velocity up! Simply genius! I really am guessing at how this works though haha!
I am very intrigued by the dual twin scroll turbos. Im guessing that they use using 2 cylinders per "scroll" and using pairing them as close to 180 as possible to keep exhaust velocity up! Simply genius! I really am guessing at how this works though haha!
Wasn't factory, but it has been tried.....
edit, found this on a turbo forum:
A twin scroll turbine housing uses dual side by side passages into the housing. When coupled with a pulse converter manifold that separates exhaust pulses as many crank degrees in the firing order as possible, a twin scroll or divided housing works to reduce lag, decrease exhaust manifold backpressure on the top end, reduce the potential for reversion, and increase fuel economy. The twin scroll is based off the same reasoning a tri-Y header uses: keep spent exhaust gases out of an adjacent cylinder drawing in fresh air. At high rpm on a turbo car, exhaust backpressure is usually significantly higher than atmospheric pressure, and often higher than intake manifold pressure as well. A divider between each of the two volutes allows the cylinders to expel the exhaust gases without it interfering with the fresh air for combustion. Since there are two openings, each a smaller overall volume than a single scroll design, the exhaust velocity of each pulse can be maintained. This also spins the impeller more easily because lag is a function of the scroll area. A single turbine housing opening isn't as efficient since cylinders on the exhaust stroke of the 4 stroke cycle contaminate the cylinders that are on overlap with exhaust gas. A conventional turbine housing is not as effective in using exhaust pulse energy to help spin the turbine up to speed as it does not exploit the energy contained in the pulses as well.
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Joined: Sep 2008
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From: MI
Staging Lane
Joined: Sep 2008
Posts: 99
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From: MI
this, when the engine is built correctly for it, gives a larger turbo better midrange response