We all know Porsche is capable of building powerful, naturally aspirated screamers like the 520-hp engine in the GT3 RS. And Porsche engineers have demonstrated plenty of forced-induction proficiency with the twin-turbo flat-six in the 690-hp GT2 RS.
Our question has to do with the turbocharged, water-cooled lump sitting
over the rear axle of the new 992-generation 911 Carrera S; how much
power is it really making?
We took a Racing Yellow 2020 911
Carrera S to a dyno to find out. Porsche claims 443 hp and 390 lb-ft of
torque from the twin-turbocharged 3.0-liter flat-six, but keep in mind,
those numbers are rated at the crank. Those specs won't directly
translate to the numbers this Porsche will put down on the dyno. A
dynamometer measures how much power and torque make it to the ground, or
in this case, the cylindrical drums on which the car is driving during
dyno testing.
Some of the power and torque produced at the crank
is used to spin the transmission, driveshaft, differential, and half
shafts before it gets to the wheels. For that reason, wheel horsepower
and wheel torque will always be lower than the numbers measured at the
crankshaft. The percent losses are extremely difficult to measure and
vary from car to car, but a 15 percent drivetrain loss is a usable
approximation.
So here are the numbers: the 2019 Porsche 911 Carrera S produced an average of 414 hp and 406 lb-ft of torque at the wheels over three dyno runs in fourth gear. The last time
we measured the 520-hp GT3 RS on a dyno, it made 430 hp at the
wheels—just 4 percent more than this comparitively pedestrian Carrera S.
Also,
look at that torque figure for a moment. This 911 is putting down more
torque at the wheels than Porsche is claiming it produces at the crank.
Taking into account a 15-percent drivetrain loss, these numbers
translate to 476 horses and 467 lb-ft at the crank, increases of 33 hp
and 77 lb-ft over Porsche's estimates.
The shape of the power and
torque curves are representative of the engine's forced induction.
There's a huge spike in torque between 2,000 and 2,500 rpm, which is
much earlier in the rev range than what you'd typically see from a
small-ish-displacement engine. Horsepower builds as the engine spins
faster and faster, only peaking right up against the engine's 7,200-rpm
redline.
As this car is an early build, it's hard to say if its
dyno performance is representative of the standard-production 992
Carrera S. But if so, you'll be getting a lot more power and torque than
you bargained for. We don't expect to hear many 911 buyers complaining.
