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Dutch924-racer
Joined: 23 Jul 2007 Posts: 1076 Location: The Netherlands
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Posted: Sun Jul 17, 2016 5:00 am Post subject: recirculation valve when using 944 turbo |
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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 ?
_________________ 937 trackday car
Series 2 engine
951S turbo and intercooler
Fast road camshaft
Forge recirculation valve + boost controller |
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Cedric
Joined: 27 Aug 2004 Posts: 2600 Location: Sweden
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Posted: Sun Jul 17, 2016 5:05 am Post subject: |
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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. _________________ 1980 924 Turbo
www.instagram.com/garagecedric/ |
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Rasta Monsta
Joined: 12 Jul 2006 Posts: 11723 Location: PacNW
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Posted: Mon Aug 01, 2016 1:55 am Post subject: |
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I like number one as well. . .also most similar to 951 setup. _________________ Toofah King Bad
- WeiBe (1987 924S 2.5t) - 931 S3
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ideola
Joined: 01 Oct 2004 Posts: 15548 Location: Spring Lake MI
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Posted: Mon Aug 01, 2016 2:06 am Post subject: |
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#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. _________________ erstwhile owner of just about every 924 variant ever made
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 Posts: 11723 Location: PacNW
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Posted: Mon Aug 01, 2016 2:33 am Post subject: |
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Right, and it's vacuum that operates BOV, not boost. _________________ Toofah King Bad
- WeiBe (1987 924S 2.5t) - 931 S3
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ideola
Joined: 01 Oct 2004 Posts: 15548 Location: Spring Lake MI
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Posted: Mon Aug 01, 2016 2:38 am Post subject: |
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Rasta Monsta wrote: | Right, and it's vacuum that operates BOV, not boost. |
Oops, yes, you're right. Edited above... _________________ erstwhile owner of just about every 924 variant ever made |
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Rasta Monsta
Joined: 12 Jul 2006 Posts: 11723 Location: PacNW
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Posted: Mon Aug 01, 2016 5:01 am Post subject: |
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Actually in reference to OP's diagram.....
_________________ Toofah King Bad
- WeiBe (1987 924S 2.5t) - 931 S3
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Fasteddie313
Joined: 29 Sep 2013 Posts: 2596 Location: MI
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Posted: Mon Aug 01, 2016 5:32 am Post subject: |
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I would choose #1 but #2 was more convenient to me so that's where it went.. _________________ 80 Turbo - Slightly Modified |
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