difference between 8.5:1 and 9.3:1 compression
 

Gents,

I have been reading about 911SCs recently and just noticed that Porsche made 3 different compression ratio motors (8.5:1, 9.3:1, and 9.8:1).

I always understood that the 9.8:1 was the compression ratio of the motor in ROW SCs from 81 to 83 and that it generated more power than the standard 8.5:1 ratio motor found in US cars.

What about the 9.3:1 to one? Was it ever offered in US cars? Is it true that the Weissach edition came with it? Does 9.3:1 provide more power/torque than the 8.5:1?

Thanks

Not sure about if ti was on US cars.

All other things being equal a higher compression ratio means more power.

The 9.3 was used on all 80-83 with the lambda, it continued using 8.5 on the euro until the 9.8 arrived in 81.
Bruce