The M6 reels it in fairly quickly and then pulls away just slightly up top. The GT3 RS 4.0 hangs in there really well especially considering it is down on power (457 to the wheels versus around ~500 wheel) and does not have a quick shifting dual clutch transmission. With a better dry launch this would be a very, very close race between the two cars. The GT3 does a great job with is naturally aspirated smaller motor.
This same GT3 previously was seen in action versus a Nissan GTR that put much more distance on the GT3. Yet, we recently saw a video of an F13 M6 putting bus lengths on a GTR. So what's with the seemingly opposite outcomes? What is seen in the video below sure supports the GTR that raced this same GT3 RS 4.0 having a tune in addition to its exhaust mods.