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    • Porsche maxing out the naturally aspirated flat-6 with 4.2 liter 2017/2018 911 (991.2) GT3 RS?

      The current 991 generation Porsche GT3 RS has a 4.0 liter flat-6 motor which produces 500 horsepower. The 911 obviously received a facelift in the form of the 991.2 generation which brought turbo power to the Carrera and Carrera S but the GT3 and GT3 RS will remain naturally aspirated.


      That brings up the question, where do they go from here? The current rumor is the GT3 will go to 4.0 liters plus offer a manual transmission option and the GT3 RS will go to 4.2 liters. That is basically it and what is likely the final evolution of the naturally aspirated flat-6 unless Porsche produces a new architecture which is unlikely. They will likely bump the stroke slightly as they have nowhere else to go.

      991 GT3 3.8 bore x stroke (mm): 102.0 x 77.5
      991 GT3 RS 4.0 bore x stroke (mm): 102 x 81.5

      This may very well be the last hurrah of the NA flat-6. If so, at least it will go out with quite the bang.






      This article was originally published in forum thread: Porsche maxing out the naturally aspirated flat-6 with 4.2 liter 2017/2018 911 (991.2) GT3 RS? started by Sticky View original post
      Comments 4 Comments
      1. Stevenh's Avatar
        Stevenh -
        I'm fine with that being the largest size... find power in the head and valve-train but, more importantly, find ways to make it faster by losing weight with each new generation.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Stevenh Click here to enlarge
        I'm fine with that being the largest size... find power in the head and valve-train but, more importantly, find ways to make it faster by losing weight with each new generation.
        I'm sure they can eek out a few more horses but I doubt they will continue developing the naturally aspirated flat-6 much longer beyond the 991.2.
      1. BlackJetE90OC's Avatar
        BlackJetE90OC -
        Maybe next generation GT cars will see some hybrid tech trickle from the 918. Instead of ruining the GT cars with turbos.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by BlackJetE90OC Click here to enlarge
        Maybe next generation GT cars will see some hybrid tech trickle from the 918. Instead of ruining the GT cars with turbos.
        That's a pretty good point. Hybrid technology could augment the needed torque boost.

        They'll be way heavier though...