Best Air Filter, AirBox, Air Intake
Since the fuel os injected under hi pressure as it expands it absorbs heat(cools) the charge
Heat of expansion PV = nRT stuff
The sls makes 25% more hp but only 8% more torque
Primarily by moving the peak down the band
5000 to 4750 or 5% lower
Since T = 5252/rpm x HP
Therefore if you maintain power at a lower rpm you will increase torque
The base c63, pp and 507 have 450/480/507 but essentially the same torque since no cam or intake revisions were made
I won't say it is 'easy' to increase peak power, but it is 'easier' than making torque
They can measure pressure and flow before/ after each system component
That way they can optimize power/torque/efficiency/sound
The exhaust is a calibrated system component
It will be hard to improve on without impacting one of the parameters negatively



