The Porsche 718 Spyder GT4 RS has 350bhp per tonne, slightly more than the Cayman GT4 RS's 348bhp per tonne
 
            
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GT3 engine transplant marks the end of an era as the popular convertible is prepared for electrification
          
       
  Porsche 718 Spyder GT4 RS is 493bhp Boxster swansong