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Would that design not create a lot of turbulence with the return right after the turbine?

I was going to mention that but thought i would sit back and see how it went :)

Being at right angles to the turbine flow it stands a chance of being pretty bad.

But, if it turns out to be bad, the concept can still be valid. Because Stao can always have the relationship between the WG and the housing fixed, he can come up with a suitable dump pipe that will allow the WG re-entry to be further down and it can be a standard item he can sell with it. The best bet would be to make it like the cheapy split dumps for Nissan housings with the return down near the floorpan bend in the main dump. When you assemble it you just present the dump to the turbo and WG flanges and do everything up (provided there's enough room to swing the necessary spanners.

The wastegate entry being at a right angle doesn't cause as many problems as one would assume. At least not in my application. Stao welded my gate off the housing like that, but it has no problems with boost control at all, though my tuner and I both thought it would be an issue. Mine is venting to atmo though.

I'm not worried about boost control. I'm more concerned with the disruption to the flow patterns of the turbine exit flow. A Garrett engineer once told me (and several others, to be sure) that the very best turbine exit is a nice, smooth, conical expansion from the turbine diameter up to the proper dump diameter. Shallow cone angle preferred (obviously) but sadly in the real world everything is compromised by how much space is available. But the rest of his message was that anything that disrupts that flow field after the turbine costs flow through the turbine, which ultimately simply comes back to increased back pressure for the same amount of power and less power able to be taken from the exhaust energy. OEM wastegates, like the Nissan one, direct the WG flow across the turbine flow (because the flap directs the flow that way). And it works....but it is one of the reasons that people like to be able to go external gate - so they can get rid of the disruptions in the turbine exit flow. Yeah, yeah, better boost control and all that too. But having the WG flow across the turbine flow is a pretty crap thing to copy if you can avoid it.

Clearly Stao intends this housing to just go where the factory one was and hook up to factory flanged dumps pipes, and so he has little choice in the matter if he wants it all to fit in. But my point was merely that if it turns out to suck in any way, he can still use (most of) the idea.

And now that I think about it, a small tweak to the design of the prototype he showed above would make it suit the split dumps really well. Just move the WG return to the location where the factory WG is so that the gas is kept separate from the turbine flow in the housing, Bob's your uncle. You could even put the divider into the housing proper, remove the projecting divider from the dump pipe and get a more reasonable seal between the two chambers. Probably need to make your own gasket, but that wouldn't hurt.

I agree GTSBoy, I just don't believe people understand high velocity airflow very well.

Imagine the airflow is water and you will perhaps realise the flaws in that design a little better.

Hey I want one of those on my SS2 rear housing but I think if you give the flexibility of being able to weld the pipe in anywhere we like and just build ports into the housings would be great.

Well it doesn't have any room any where else for plumb back. Thats pretty much the only spot that can be plumbed back with. Alternatively I can make them with a bit of a dump pipe, that will make the plumbing much easier.

Less talky, more "run that sucker up on a dyno and see what happens" :)

This.

Do it with a G3 so we can see how deep the rabbit hole goes.

I will make some thing better for the dyno testing. This one was just to see how do able it was. Even tho it looked crap, that was alot of work.

Here's some thing better looking: I've restored a T04Z which some guy was about to throw out into the dump. It had a bent shaft, warped turbine ring grove, balancing was out 300% (funny how it was sold like that and no wonder it was very noisy). Plus some inexperienced mechanic stripped it and damaged the thrust pin and bearing caging. Good thing is the original bearing cartridge didn't look to bad. Other wise I will not be able to restore it.

Its also fitted with our SS3's .70 comp housing and a split pulse .84 turbine housing:

comp.JPG

turbine.JPG

side.JPG

Far as I know it will be going to a GTR and make some very lazy KWs, likely it will be back for the VNT module upgrade in near future.

What size is the compressor outlet on your SS2 stao? I need to buy a 90 deg silicone bend but under on what size I need. Would probably be 2.5" yeah?

that would be 2.5 inches outlet with a 4inches inlet. Usually run a 2.5 inches 90 degrees long leg pipe to the factory cooler piping and a 4 inches metal induction pipe with pod.

Tested the atr28g2 on the 180sx today at wsid

Was very busy and only managed one decent run

On 20psi boost got 12.4 at 120mph shit 60ft 2.2 had abit if wheel spin on launch

Tried high boost 24psi but blew a cooler hose off and ruined the run also track temps were 30c in the middle of the day

Will be definately heading back in a few weeks on a Wednesday night when it's cooler and hopefully crack that Dam 11s

Still got 4-5psi in it so maybe 20kw and will let down the Tyres down more as I got et streets and was on 30psi try 25 or less psi

I've driven it hard since I got it tuned and just before I left I gave it a few test runs and cooler hose didn't blow off

But decided to come off at the runs spewing

The Tyres have made a huge difference to street Tyres

Takes off like a bullet no wheel spin on the street at all in any gear where as before you can't get traction till 3rd gear if your Aggresive

I've driven it hard since I got it tuned and just before I left I gave it a few test runs and cooler hose didn't blow off

But decided to come off at the runs spewing

The Tyres have made a huge difference to street Tyres

Takes off like a bullet no wheel spin on the street at all in any gear where as before you can't get traction till 3rd gear if your Aggresive

Sorry if I missed it but what tyres did you run? Good result with potential, bring on the 11s!

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