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Turbo Flange Over Lap ?

Boosted Zed
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Boosted Zed Mentor

Boosted Zed

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Recently we have checked a few stock turbo's as well as one after market turbo and noticed the flange of the turbo is smaller than the flange of the

exhaust manifold both stock and bling staino ones. So the gases rushing out fo the engine through the manifold hit a big edge of the turbo flange. Not good. Might we worth checking and grinding out and match porting if you are changing turbo's or having it off for any work.

See the pics as we found 2 to 3 mm gap. We found this by simply doing a test not suspecting anything and actually suprised to see how bad the overlap was. We found this problem by carefully tracing out the turbo flange and cutting out of card board and laid it over the exhaust manifold and it became very obvious. With this edge jutting out if would make a difference to flow as would create a lot of turbulence especially at high revs.

To fix this all you need to do is remove the turbo exhaust housing and mark out and match port to suit. FREE POWER.

Will check GTR turbo's asap.

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Boosted Zed Mentor

Boosted Zed

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I should ask James from Abrasive Flow as he match ports to head and turbo and extrude hones the GTR exhaust manifolds and mathces to turbo. I know he opens up the exhaust manifolds a bit going into the turbo.

GTRgeoff Grand Master

GTRgeoff

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It is Pete. The manifold has a lip that turns the flow and finishes in a sharp edge. Not a good situation for flow but they maust have had some reason. Anyway it's probably just for stock boost, and would be an impediment at greater boost levels/exhaust velocities.

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