jdw
Member
Joined: January 2012
Posts: 41
|
Post by jdw on Mar 25, 2014 15:45:03 GMT -5
Howdy everyone hope all is well for group. While reading a Diesel Power Magazine I read a small info clip that brought up Fords 2011 diesel engines using a Garrett Single Sequential Turbo. So when I returned from work I did a little research and discovered it is a turbo with two compressors and a single turbine pretty interesting! But i read it was failure prone and looking at some cut a ways both compressors feed a single outlet. From what little info I found it has twin 66mm compressors that flow similar to an 84mm turbo. Thought I would see what ya'll think about it sure would make a very unique engine. JDW content6.flixster.com/photo/12/79/28/12792812_gal.jpg cut a way pic image.dieselpowermag.com/f/whats-new/67l-power-stroke-will-need-more-air/33660165/67-sst.jpg front shot |
|
|
|
Post by racket on Mar 25, 2014 16:57:32 GMT -5
Hi JDW
Nice cutaway pic, thanks for the Link .
Theres been some discussion about this turbo before as to whether or not it'd be suitable for a DIY turbine build , the general feeling is that whilst it satisfies the special needs of the diesel engine its configured for ,its "complication" won't be any better for a turbine build than a normal turbo with a single comp wheel ,.......... the turbo is an interesting oddity :-)
Cheers
John
|
|
|
|
Post by enginewhisperer on Mar 25, 2014 19:49:02 GMT -5
I had a look at one of these in person the other week. It's a pretty interesting solution for lower inertia, but there's a worrying amount of shaft overhang from the front bearing!
When I first heard about it I thought they were doing a two stage compressor - but it's just two parallel compressors in one housing both exiting into a single scroll.
|
|
|
|
Post by racket on Mar 25, 2014 20:18:40 GMT -5
Hi Andrew
Were there any other "mechanical bits" to regulate flow from the unit , inlet "valves?" and/or outlet mods , or was it just a turbo with a "split" compressor wheel ??
The overhang is severe , you wouldn't want to get the shaft gyrating from surge :-(
Cheers
John
|
|
jdw
Member
Joined: January 2012
Posts: 41
|
Post by jdw on Mar 26, 2014 7:17:00 GMT -5
John, i was kind of thinking the same, it's more of a novelty than anything really. Enginewisperer I thought kinda the same thing I was thinking it was two separate compressors that could be duct-ed one into the other to make a two stage compressor. I wonder if the quill would be long enough to place two "standard" compressors facing the same direction with the front feeding the rear. I could be possible but would be quite a bit of a challenge.
JDW
|
|
|
|
Post by enginewhisperer on Mar 26, 2014 21:38:37 GMT -5
no flow control hardware that I could see in the turbo, although they could have done something external in the pipe work.
Since the compressors both outlet into the same space they couldn't do much with it though I think, so as far as I can tell, it's really just a way of getting more flow from a smaller diameter turbine, which will have lower inertia than a larger diameter single sided one.
|
|
|
|
Post by enginewhisperer on Mar 26, 2014 21:45:05 GMT -5
one interesting thing you can just see in the cutaway pic though is the solenoid to control the NGVs in the turbine housing.
It actually uses a hydraulic actuator to move them, powered by the lubrication oil feed and controlled by the solenoid.
I guess it provides much higher force capability than the old vacuum actuators they used to use (where the vanes could seize up and overboost the engine)
There's also a wastegate on that turbo, so I guess they have gone for extreme low rpm response - undersized turbine, low inertia compressor, variable vanes, etc
|
|
