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This is just some guessing but if you look at the difference in total TQ, HP, and the rpms they are quoted at something is up.
I would guess if the motors are identical except for cam timing the total TQ would stay about the same but move up the rpm range.
However, TQ increases about 7% with the Carrera 3.0. indicating a substantial increase in efficiency between the two motors.
And, Porsche quotes TQ peak at the same rpm for both motors.
The 3.0 Carrera quotes 188# @ 4200rpm.
The SC quotes 175 # @4200.
Why would they quote TQ at the same rpm but quote HP peak at 5500 for the SC and 6000 for the Carrera 3.0? If the HP peak looks to have moved up 500rpms. I would think the TQ peak should have moved up about the same.
Something is fishy with the quoting of TQ at the same RPM with both motors.
While TQ increased 7%, HP increased about 10%. This seems to be an indication that the 3.0 Carrera motor is holding its effecency better w increases in rpm.
Something more than cam timing looks to be involved in the difference between the two motors.
Maybe Porsche played w the tune w the SC to meet smog requirements.
Or, Porsche could have been playing with the numbers to a degree for some reason.
Again, the 3.0 Carrera made about 7% more power with each stroke, did so about 500rpm higher in the power band, and the efficiency's did not fall off as fast with increases in rpm.
Besides cam timing this could be due to ignition timing or A/F ratios.
It is intereasting that with Porsche's increase of the CR of the later US SC motors and droping of the air pump should have showed up as an increase or change in the peak TQ and Hp numbers but no change was quoted.
I think Porsche was to at least some degree playing w the quoted numbers.
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