The record for quickest Mercedes-Benz still belongs to Renntech as they hit a 9.68 elapsed time. ET in the 1/4 mile is based on the launch, traction, and conditions so a less powerful car can run a quicker ET and a more powerful car can run a slower ET depending on these factors.
Regardless, there is enough power here for what on paper would work out to high 8 second capability. The Weistec twin screw supercharged M156 V8 appears to be putting out over 1000 wheel horsepower at this time (a dyno graph will come at a later date). No doubt quicker times will come in time but for now we have a new World's Fastest Mercedes-Benz. Congratulations to all involved, enjoy the video below.