Divorced downpipe VTA

So I've been looking for a a while for a divorced downpipe that vents the internal wastegate gases straight to the atmosphere instead of back into the exhaust. Anybody know of anything like this for us? I know the Evo guys have o2 dump which is awesome but can't find anything like that for us.

It's due the the design of the turbine housing, with an evo turbo, the wastegates are separated from the exhaust flow by a wall in the casting.

 

Mistubishi Evo turbo

http://www.socalevo.net/gallery/albums/userpics/10991/THEVOMR105004_full.jpg

 

 

It's because of this, that the spent exhaust from the turbine wheel, and the exhaust bypassing the turbo through the wastegates are able to take different paths.

 

Subaru Impreza WRX STi turbo

you can see here, the exhaust from the turbine wheel and the exhaust from the wastegates are combined into one enclosure, which is why there are no "O2" dumps on subaru's using the stock USDM single scroll turbos.

 

http://www.turbochargerengineering.com/store/images/products/subiupg-49179-back-350.jpg

 

 

But there is hope to do this on a subaru, it is with a JDM twinscroll style turbo.

Moore performance makes a divorced downpipe with a "O2" dump for the twinscroll turbos.

 

 

 

 

http://farm9.staticflickr.com/8508/8449920472_b625e00be1_b.jpg

What's the point of an "o2 dump"?

Lets everyone within earshot know how big your penis is when your wastegate opens.

http://www.extremeturbosystems.com/ETS-Mitsubishi-Evo-X-and-Evolution-X-Dump-O2-Eliminator-Downpipe.html

 

This downpipe features a vent to atmosphere wastegate dump for an intimating sound at wide open throttle.

Should be intimidating but whatever, you get the point.

 

Anyways, on a more serious note, not sure what the advantage of having this is. I'm sure someone will jump in and say something about reduced turbulence in the downpipe's exhaust flow, thereby reducing backpressure, etc... which I can sort of see, but not really..... If it were to make any difference at all, it would be very, very, very minor.

 

Think about it. At WOT, the WG should be mostly closed...

 

I'd lean towards it mostly being a noisemaker.

 

You want to really make a difference, get an EWG.... and a larger turbo to go with it.

It reduces turbulence, promoting laminar flow, which in turn reduces backpressure...

 

All things considered, you'd be might fine with a good bell mouth designed downpipe.

there is no point to VTA with an IWG especially on a VF series turbo. The your average aftermarket DP will outflow most IWG turbos and any turbulence is minimal.

 

Get an EWG and then talk about VTA.