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spence88mph spence88mph is offline
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Join Date: Jan 2007
Location: Melbourne, Australia
Posts: 1,581
BOV is to release pressure from closed throttle surge, between shifts, anti surge housings release excess pressure from compressor surge within the turbo. They're 2 very different issues.

Interestingly, if you look at the maps, well the ones I have seen it also increases the efficiency.

The bigger 40 series GT turbos have anti surge housings standard I'm pretty sure.

Andy, compare the maps of the turbo you're looking at with and without anti surge and base your opinions there, I have heard it adds lag but I'm not sure. As you mentioned, at low boost levels I don't think this is a factor.

Would love to hear Turbocraft's opinion on this as they use and spec their own Garretts.
'89 911 M491+Turbo
'89 944 Turbo
'88 928S4
'18 C63S Coupe
Old 06-21-2011, 03:47 PM
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