Divided turbine housing spool-up idea[discussion]

[RWD4G63]

I'm bringing this thread back from the dead, simply because I am thinking about making something like this and would like some more input. I was going to use a single middle flapper though, unlike the dual one Peepers first proposed, but controlled the same way; using an internal wastegate.

The main issue I'm seeing is sealing. When the divider is closed you don't want the two scrolls leaking into each other. This means semi-precise fit and probably not stainless as it expands a lot more than mild steel.

Also, I was thinking of sealig the shaft with a brass bushing? The rest of the construction would be relatively simple.

It seems BorgWarner is coming out with something similar to this for the new EFR series as well.

EDIT: just found this guy, who basically built what I was thinking into his turbine housing. It does work. I don't really like his because there is obvious space for gases to mix around the divider though, and we all know that even something like an undivided wastegate on a divided manifold can hurt spool.

An easily rectifiable situation though.

http://www.enginebasics.com/Advanced%20Engine%20Tuning/Quick%20Spool%20Valve%20Test.html



EDIT AGAIN:

Here's the one BorgWarner is coming out with. No real shots of it yet because it's "secret".

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[forcefed86]

Couple DIY versions.

Quick spool valve built into Turbine - YouTube

Variable AR Turbine Housing aka Quick Spool Valve - YouTube

 

[RWD4G63]

Yeah that top one is the link I posted.

 

[RWD4G63]

Let it begin:

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