Vivid Racing has been a fan of the Mercedes AMG platform for many years. You might have seen our W204 Mercedes C63 video with over 1.6 million views! But we have done many more over the years including the build of our Mercedes CLS63 and Mercedes CLA45. We have even tweaked and tuned the same 4.0L Bi-Turbo Mercedes GT-S! To say we love the sound and power of the Mercedes engine is an understatement! Recently we got the chance to play with the new W205 Mercedes C63S Coupe. This car is already a monster with its 4.0L Bi-Turbo engine making 503 bhp. But with the addition of our VR Tuned ECU Flash and Weistec Race Downpipes, we transform this Coupe into a beast!

Here at our Gilbert, AZ facility, we have a Mustang All Wheel Drive dynamometer. Typically when we dyno cars in rear wheel drive, we see anywhere from a 10-20% drivetrain loss. The average we see is around 15%. Running 91 octane and on a nice spring day around 75F, our baseline test yielded a peak of 431rwhp and 463ft/lbs of torque. This is very close to our estimated 15% drivetrain loss (actual 427). Since we have done the 4.0L Bi-turbo on the Mercedes GT-S, we found on our baseline test on par.

This upgrade was done in 2 steps. First was the ECU flash along with our Agency Power blow off valve spacers to hear the turbos more when you let off the throttle. Then we did the Weistec Race Downpipes to really allow the turbos to flow maximizing the full potential of the ECU tune. Unlike the Mercedes GT-S where the ECU is right on top of the engine and takes 2 minutes to remove, Mercedes has hid the ECU in a spot that not even an ant could reach. Located between the frame rail and the engine, the Bosch MED17.7.5 ECU is almost impossible to access. Unlike the previous W204 Mercedes C63 that can be done via the OBDII port, this ECU must be bench flashed. Have no fear though, the ECU can be removed with some time, our installation instructions, and in the end is totally worth it!

Read the rest, see the dyno graphs, and watch the video on the VR Blog