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997 gt3 rear diffuser

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Old 04-17-2024, 11:02 AM
  #31  
powdrhound
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Originally Posted by De Jeeper
Do u think it can be adapted for a 996 chassis? I know the chassis r similar.
Yes. The mounting points are the exact same. You will want to have the 997GT3 flat underbody paneling installed on 996 to make a continuous flat floor nose to tail. The shape is also designed around integrating with the 7GT3 rear brake ducts. We are actually mounting this on my 996 which has the full 7GT3 underpanels and brake ducting. I'm not adding this to my 7GT3 as I don't use it on track and it has the factory center Ti muffler.

Here are the 7GT3 underpanels on my 996. The diffuser will tie in with the rear triangle and cover the whole underside of the whole engine all the way to the rear bumper. This is pretty much exactly what Porsche did with the 997GT3R which used the factory 997GT3 underpanels.





Last edited by powdrhound; 04-17-2024 at 11:19 AM.
Old 04-17-2024, 02:32 PM
  #32  
De Jeeper
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Very cool thx for the info. I already have all the 997 panels except for the last one with the naca duct. I would just have to check clearence with my fvd center exhaust. I think the muffers would be fine but the header might drop down too far?

Ill put this on my wish list for next winter.





Old 04-17-2024, 07:40 PM
  #33  
Finlander
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I'd be interested in one.

I recently took a GT3 cup diffuser and had a local guy fit it to my 991 RS. He had to fabricate brackets, mounting points, and a custom plate (silver) for airflow.




Old 04-18-2024, 04:12 AM
  #34  
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Originally Posted by Finlander
I'd be interested in one.

I recently took a GT3 cup diffuser and had a local guy fit it to my 991 RS. He had to fabricate brackets, mounting points, and a custom plate (silver) for airflow.
They did a real nice job integrating that. Similar to what we are doing except we opted to have the diffuser with a curved profile instead of flat.
Old 04-18-2024, 10:08 AM
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How does this impact heat dissipation from the engine compartment? Seems like it may block a lot of air circulation, which I know is good for aero, but is it ok for heat? Would this be ok to use for street use where speeds are typically much lower than on the track (i.e. traffic)?
Old 04-18-2024, 11:55 AM
  #36  
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Originally Posted by 8Lug
How does this impact heat dissipation from the engine compartment? Seems like it may block a lot of air circulation, which I know is good for aero, but is it ok for heat? Would this be ok to use for street use where speeds are typically much lower than on the track (i.e. traffic)?
That's a great question as that is the exit pathway for all the heat.
Old 04-18-2024, 01:26 PM
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powdrhound
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Originally Posted by 8Lug
How does this impact heat dissipation from the engine compartment? Seems like it may block a lot of air circulation, which I know is good for aero, but is it ok for heat? Would this be ok to use for street use where speeds are typically much lower than on the track (i.e. traffic)?
I honestly don't see why this would be necessary on a street car, maybe in Germany where you can often see deep triple digit speeds. This is more of a track mod to improve downforce and airflow efficiency. This is why you see this employed on all the Porsche motorsport applications now. Regarding cooling, that won't be an issue as these cars have so much reserve cooling capacity to begin with and hot air is continually extracted via the decklid fan which the Cups / RSRs don't even have. Keep in mind the diffuser is not air tight.

Last edited by powdrhound; 04-18-2024 at 01:28 PM.
Old 04-18-2024, 01:37 PM
  #38  
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Here's to hoping it clears with a Dundon setup...
Old 04-18-2024, 02:10 PM
  #39  
8Lug
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Originally Posted by powdrhound
I honestly don't see why this would be necessary on a street car, maybe in Germany where you can often see deep triple digit speeds. This is more of a track mod to improve downforce and airflow efficiency. This is why you see this employed on all the Porsche motorsport applications now. Regarding cooling, that won't be an issue as these cars have so much reserve cooling capacity to begin with and hot air is continually extracted via the decklid fan which the Cups / RSRs don't even have. Keep in mind the diffuser is not air tight.
certainly not necessary for a street car. My question was more for cars that serve double duty since I Imagine most owners here don’t have a dedicated track car. Is there a downside from using this is on the street. The deck lid and fan push air in, they don’t extract heat. Heat is extracted through the bottom except for when car is parked and fan not running then heat radiates up and through the fan inlet opening. I think you answered my question though, seems like this is a track specific mod.
Old 04-18-2024, 02:20 PM
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Originally Posted by 8Lug
certainly not necessary for a street car. My question was more for cars that serve double duty since I Imagine most owners here don’t have a dedicated track car. Is there a downside from using this is on the street. The deck lid and fan push air in, they don’t extract heat. Heat is extracted through the bottom except for when car is parked and fan not running then heat radiates up and through the fan inlet opening. I think you answered my question though, seems like this is a track specific mod.
Rest assured, cooling won’t be an issue. There is plenty of room for air to get pushed out on either side of the diffuser. Keep in mind the vast majority of engine cooling is handled by the front radiators and not the tiny bit aided by the decklid fan. For a dual duty street/track car this would be a great addition in my opinion.

Last edited by powdrhound; 04-18-2024 at 02:25 PM.
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Old 04-18-2024, 02:24 PM
  #41  
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Originally Posted by powdrhound
Rest assured, cooling won’t be an issue. There is plenty of room for air to get pushed out on either side of the diffuser. Keep in mind the vast majority of engine cooling is handled by the radiators and not the tiny bit aided by the decklid fan. For a dual duty street/track car this would be a great addition in my opinion.
cool. Thanks for clarifying.
Old 05-07-2024, 02:33 PM
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@powdrhound any updates?
Old 05-07-2024, 02:40 PM
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Cool to see new parts still being developed for these cars!
Old 05-08-2024, 12:42 AM
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Originally Posted by kk2
@powdrhound any updates?
We had an unexpected engine rebuild and had to put this on the back burner for another month or so. This will get done just may take a bit more time at this point.
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Old 07-10-2024, 11:31 AM
  #45  
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Any updates? Eager to get one under the car!


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