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Borg Warner variable twin scroll turbo

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Old Feb 10, 2019 | 11:58 PM
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Seven!!'s Avatar
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Borg Warner variable twin scroll turbo

Hey guys I was wondering if anyone had any personal experience with this turbo or quick spool valve. The first two pictures are of what people are calling the Borg Warner variable twin scroll turbo. I cant find any info on this turbo in regards to price, specs, or true name. Has anyone seen this before? Its supposedly been around since 2015 so its not that new.


This video explains the concept.

If its a concept that hasn't come to the market, have any of you used this on a twin scroll turbo. Its called a QSV or quick spool valve and works similar if not the same as the integrated QSV on the turbo pictured above.



Any info or insight would be appreciated. Thanks.

Last edited by Seven!!; Feb 11, 2019 at 12:00 AM.
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Old Feb 11, 2019 | 06:00 AM
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Turblown had similar idea for their manifold or turbo.. i cant remember exactly. But ist the first time i see one of those. Interested to know too.
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Old Feb 11, 2019 | 06:39 AM
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Quick spool valves turn twin scroll turbos into '87 Turbo II turbos, functionally.

The Audi guys hated it when I pointed out that the "new technology" they were playing with was 25 years old and was abandoned after a couple years...
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Old Feb 11, 2019 | 11:28 AM
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From: https://www2.mazda.com/en/100th/
Originally Posted by peejay
Quick spool valves turn twin scroll turbos into '87 Turbo II turbos, functionally.

The Audi guys hated it when I pointed out that the "new technology" they were playing with was 25 years old and was abandoned after a couple years...
you have to remember that its only new technology when the Germans do it, it doesn't matter if Mazda did it 25 years ago.



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Old Feb 11, 2019 | 02:27 PM
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sure, put a significant restriction where flow is important. great idea for making power at 3000 rpm. while giving it up where it counts.
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Old Feb 11, 2019 | 02:56 PM
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Originally Posted by Howard Coleman CPR
sure, put a significant restriction where flow is important. great idea for making power at 3000 rpm. while giving it up where it counts.
To be fair to the Audi guys, they had no option to properly run a twin-scroll turbo because five doesn't divide into two.

One person did make a 5 into two header, and it apparently worked far better than it looked. Cylinder 3 got divided into each side.
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Old Feb 12, 2019 | 11:50 AM
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One of those Borg Warner VTF housings somehow made it into eBay (sold) last year. Not really sure how since I don't believe it was offically released.
There are some good photos at least
https://www.ebay.com/itm/BorgWarner-...-/113038354469
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Old Feb 12, 2019 | 01:44 PM
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Oh man, I missed that. I guess that is to be expected when I stopped my daily Ebay EFR searches.

Looking at my EFR 7670 dyno chart in the 2,000-2,500rpm range versus modified sequential twin FD dynos in the same rpm range I am starting to think that even at low rpm keeping the exhaust free flowing is very important on our motors (because my EFR 7670 made more power at 2,000-2,500rpm despite making less boost).

My new idea is twin turbos with both exhaust open all the time, but feeding the compressors in series at low rpm/low boost/ low throttle demand so the boost is compounded and then switching compressors to parallel once desired boost is achieved.
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Old Feb 12, 2019 | 06:49 PM
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That was on display at PRI years ago, it was put on the back burner as the mechanical actuators were unable to operate quickly enough and the turbine would overspeed. I was told that until there was an electronic control option in their parts bin, development on the project was basically over.
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