Grant:
rickman:

911 R (1967) had a high rev engine.

the 991 R should have a similar engine with a 3.8 510 HP... engine... = 135 HP / L

 

How would the 3.8L get 35hp more than before?  It already revs to 9k (and has not been without incident).  Don't think the compression can go much higher and still work on pump fuel.  Maybe different camshafts that make peak hp right at 9k?

 

if the R 991 is very light , it should be , we can imagine a sharper motor with less torque down and more power at the top . Less torque down allows for narrower tires ... it's a virtuous circle.