How come the engine size of a Porsche 997 is very compact but the performance can still match supercars ?

What makes it so small but still have high performance ? Is there any uniqueness in design ?|||%26gt;How come the engine size of a Porsche 997 is very compact but the performance can still match supercars ?





Compact in what way? The overall dimensions of the total engine and related parts are pretty similar to what you'll find in most cars, with the biggest differences in dimension being accounted for by the boxer layout (making is shorter and wider). And as far as displacement: at either 3.6L was the base model, or the 3.8L used in the S... this is again in the same realm of similar offerings with the Porsche coming in just under 4L and much of the competition coming in just above. While less, this is a pretty small difference in terms of just displacement (and if you are talking about the Turbo models, then even less meaningful).





%26gt;What makes it so small but still have high performance?





Again, it's not especially small... but in terms of power, there are many factors including displacement, compression, fuel mapping, etc... as well as headers and other exhaust components, the intake. All of which figure not only for peak power figures, but maybe even more importantly, the usuable power band. And that is just power... performance itself is much more about suspension geometry, power against the weight of the car, keeping unsprung rotating mass down, etc (this is why a Star Mazda with ~200hp will completely rape all kinds of supercars with two or three times it's power... and in that case, with an engine that really is much smaller).





%26gt;Is there any uniqueness in design?





There are two main apsects that are uncommon compared to most cars out there at the moment... first is that the 997 is rear engined, and second is that the engine is a boxer. The boxer engine does allow for a lower CG for it's weight, and this is quite important when paired with a rear engine design... but these are just elements. The 997 is a very well developed performance platform thanks mainly to it's on going development by both Porsche and privateer racers going back through all rear engined Porsches up to the current designs.|||If you mean small in internal displacement, by only having a 3.6 liter volume, the reality is that power alone does not mean anything. It is the ratio of power to weight that matters.

A huge truck engine could have twice as much power, but if it weighs 4 times as much, it will not outperform.

Smaller combustion chambers are always inherently more efficient than large ones because of the propagation delay.