Putting a IPD Plenum in a 991
Race Director
Joined: Nov 2014
Posts: 13,799
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From: FL
Great product, and nice you documented it.
As a more informative DIY, I'm sure many guys would like some helpful audio explanations as well.
This is no easy project on a 991, so nice job accomplishing it. Left mine to the dealer. Not as talented as you.
Very happy with the IPD. Did BMC air filters too.
As a more informative DIY, I'm sure many guys would like some helpful audio explanations as well.
This is no easy project on a 991, so nice job accomplishing it. Left mine to the dealer. Not as talented as you.
Very happy with the IPD. Did BMC air filters too.
Rennlist Member
Joined: Nov 2010
Posts: 647
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Performance
Can you comment on the performance improvement based on the installation. I had one on my Cayman and it seemed to improve throttle response, but I didn't experience any noticeable performance gains. Thanks
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Rennlist Member
Joined: Jan 2016
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Unless you have empirical evidence (i.e. before and after dyno), this is pure speculation. More airflow from a single bolt-on part can mean less power just as often as it can mean more.
Rennlist Member
Joined: Sep 2002
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From: In a van down by the Ottawa River ...
My purchase decision was based on that I've done sub-sonic velocity air mass flow modeling and design for piping systems. The features of the IPD design will increase volumetric air flow efficency into the cylinders feed tubes. Plenum has less turbulence with the flow diverter and dimples reduce boundary friction which can be quantified by fluid mechanics analysis.
With the increase air mass, some car's may need the air/fuel ratio adjusted to see power gains by increasing the fuel level injected and spark timing changed. Modern ECUs with performance driven maps can automatically optimize the AFR and spark timing for the minor plenum change. The COBB tuner maps does include IPDs plenum in the allowed hardware changes.
With the increase air mass, some car's may need the air/fuel ratio adjusted to see power gains by increasing the fuel level injected and spark timing changed. Modern ECUs with performance driven maps can automatically optimize the AFR and spark timing for the minor plenum change. The COBB tuner maps does include IPDs plenum in the allowed hardware changes.
But P.T. Barnum certainly did...
Race Director
Joined: Nov 2014
Posts: 13,799
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From: FL
Originally Posted by 1Gunner
Of course Porsche engineers would never have considered such things...
But P.T. Barnum certainly did...
But P.T. Barnum certainly did...
They did consider it. They saved it for the GTS model. Aluminum X51 Plenum. Accounts for 50% of X51 Powerkit gains.
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The plastic OEM Carrera S Plenum
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Last edited by STG; Feb 21, 2017 at 08:47 AM.
Race Director
Joined: Nov 2014
Posts: 13,799
Likes: 208
From: FL
Originally Posted by R_Rated
Have a part number on the flanking pieces?
Not sure if the bottoms would fit on a non X51 car though?? The X51 may have a different piece they connect to?? Not sure.
Maybe our resident expert the real "Plenum" can find out. He just bought a GTS.