Jailbreak Tuning R231 SL63 AMG dyno tune results - +70.7 horsepower
Here are tuning results from tuner Jailbreak Tuning who worked on this R231 SL63 AMG using the HG Motorsports Dyno Dynamics dynamometer. The SL63 of course has the twin turbo 5.5 liter M157 AMG V8 that responds very well to tuning. The Dyno Dynamics is known as a conservative dyno but HG Motorsports has theirs reading a bit high with their correction factor. The graph states flywheel horsepower but considering M157 based vehicles are a bit underrated to begin with and Mercedes rates the output at 530 at the crank the numbers are at least close what a Dynojet would show at the wheels.
Regardless, the pre-tune baseline is 517.2 horsepower. After the tune? 587.9 horsepower. At roughly 3800 rpm the torque increases by 129 pound-feet. That is a kick in the pants down low that will be felt.
At this point a lot of tuners have tunes that increase the horsepower and torque of the M157. The differentiating factors are how aggressive a tuner can be while keeping things safe and how much control they have over the ECU. These results are about what one should expect from any decent tuner. The gains certainly are solid and show that there are big torque gains to be had down low on the M157.