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recirculation valve when using 944 turbo

 
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Dutch924-racer  



Joined: 23 Jul 2007
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Location: The Netherlands

PostPosted: Sun Jul 17, 2016 5:00 am    Post subject: recirculation valve when using 944 turbo Reply with quote

On me new engine I am going to use the 944 S turbo and bought a Forge recirculation valve.

I looked at how the hook it up on a 911 turbo (they use option 1).

What will be the best option for the 931 ?


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Forge recirculation valve + boost controller
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Cedric  



Joined: 27 Aug 2004
Posts: 2600
Location: Sweden

PostPosted: Sun Jul 17, 2016 5:05 am    Post subject: Reply with quote

I would want as little pressurized volume as possible before the compressor to minimize any risk of compressor stall. So nr 1 would be my choice.
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Rasta Monsta  



Joined: 12 Jul 2006
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Location: PacNW

PostPosted: Mon Aug 01, 2016 1:55 am    Post subject: Reply with quote

I like number one as well. . .also most similar to 951 setup.
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ideola  



Joined: 01 Oct 2004
Posts: 15548
Location: Spring Lake MI

PostPosted: Mon Aug 01, 2016 2:06 am    Post subject: Reply with quote

#1 is also effectively how the 931's integral recirc valve works. The chamber goes straight through into the pre-compressed chamber and into the post-compressed outlet of the compressor housing, and is opened up for pass-thru when the spring compresses. The one difference on the 931 from the #1 diagram is that the de-pressurized (vacuum) signal comes from the intake plenum rather than at the throttle plate. The diagram above doesn't make it clear that the "signal" line should be post throttle plate.
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Last edited by ideola on Mon Aug 01, 2016 2:39 am; edited 1 time in total
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Rasta Monsta  



Joined: 12 Jul 2006
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PostPosted: Mon Aug 01, 2016 2:33 am    Post subject: Reply with quote

Right, and it's vacuum that operates BOV, not boost.
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ideola  



Joined: 01 Oct 2004
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Location: Spring Lake MI

PostPosted: Mon Aug 01, 2016 2:38 am    Post subject: Reply with quote

Rasta Monsta wrote:
Right, and it's vacuum that operates BOV, not boost.

Oops, yes, you're right. Edited above...
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Rasta Monsta  



Joined: 12 Jul 2006
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PostPosted: Mon Aug 01, 2016 5:01 am    Post subject: Reply with quote

Actually in reference to OP's diagram.....


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Fasteddie313  



Joined: 29 Sep 2013
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PostPosted: Mon Aug 01, 2016 5:32 am    Post subject: Reply with quote

I would choose #1 but #2 was more convenient to me so that's where it went..
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