One turbo per cylinder 1

[Deltona]

C'mon guys, tell me I've stumbled on something pretty new!

http://s103.photobucket.com/albums/m127/Deltona_II/miscellaneous/?action=view&current=P1000153.jpg

Pros and cons?

Dunno myself having only taken the pic today and not had time to think about it, but I wonder what the spool up time would be like? If one turbo relies on multiple hits of the gas pulses from the various cylinders hitting it to spin it up (hamster on a wheel) then each one is going to spin up slower perhaps (hamster with 3 broken legs)? But then, you have got four of them to offset that effect perhaps....

Thoughts anyone, good bad or otherwise?

 

[IceStationZebra]

Let the flaming begin!

Here is my quick list:
Cons
- spool-up
- underhood heat
- packaging
- sound (unless you like 4x the whine)

Pro
- short inlet/outlet runs

ISZ

 

[patprimmer]

Cost???

I like the turbo to head exhaust volume and surface area

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

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for site rules

 

[evelrod]

If this were an aircraft or marine application, maybe. In fact, probably. Automotive, not. The lag, spool up time would be a killer. The rest of the problems, heat, etc. would be manageable, not a great deal different than one giant turbo. And, yes, the cost factor would also be a giant factor for any production unit. Lots of rich people out there, though.

Rod

 

[rmw]

Actually, I love a good turbo whine. 4X, now that is just devine.

rmw

 

[SomptingGuy]

But the sound would be dreadful, because they'd all be at slightly different speeds, creating beating and other noises.

- Steve

 

[thruthefence]

lots of 'wank-factor'.

 

[mattsooty]

Not sure I can imagine this suceeding in any application....

720degCrank is way too long a delay between each blowdown event.

MS

 

[Lou Scannon]

Holy unsteady flow Batman!
I wouldn't expect a turbine designed for quasi-steady flow to operate with any kind of efficiency or design margin under these conditions. Solution: put a plenum between the exhaust port and the turbine?

 

[MikeHalloran]

Nice packaging job.
I'd expect the turbos to die young from fatigue due to the unsteady flow.

A while back I worked on a big go-fast boat that was going to have nine turbos per engine. They were staged; three running at low pressure, six running at high pressure. I think the engine had 18 cylinders, but I'm a little fuzzy on that. I was only working with the exhaust plumbing after the low- pressure turbos. It would have looked nice with three shiny 24" diameter zoom stacks on each side, but they wanted it quiet, too, which meant mufflers (no space for them in a go-fast boat) and an underwater exhaust system (with a 32" i.d. seacock). It would have been fun, but the engines went out of production before they finished the plans.



Mike Halloran
Pembroke Pines, FL, USA

 

[CH5OH]

the compressor on a turbo is a centrifugal type so it has a steep efficiency curve, or in other words it has its best efficiency on one load point of your engine so different technologies developped:
waste gate valve:BEP turbine on 90% of full load, beyond that the bypass over turbo opens
turbo's of different diametre in cascade (with bypass valves over them. this to cover the full load range of the engine.
further, at the exhaust you have two main systems:
-constant pressure system:exhaust gasses are collected and allowed to expand in the big diametre collector prior to entering the turbine
-pulse pressure system:exhaust gasses are individually piped to the turbine in such a way they hit the turbo in a synchronised manner (spaghetti outlet)or like in example one turbo /cylinder.it will give peak performance on one point of load curve of the engine(for which the exhaust pipe/nozzle is designed)