Why would it glow purple?  Regardless, this an awesome video of a 5.0 BMW V10 strapped to engine dyno.  This monster is music to our ears.  Bavarian Motor Works at it’s best.

Enjoy.

“We love the 5.0-litre V10 from BMW. Besides having an affinity for any engine with more than eight cylinders, the torque-happy 5 litre sounds like straight glory and is happy to induce all sorts of tail-wagging fun from the outgoing M5. The minds at Dinan have taken the time to put the engine through the standard performance ringer by boring and stroking the block to a full 5.8-litres, dropping a set of performance cams into the head, bolting on a dry-sump oil system and wrapping the whole project up with a set of racing exhaust headers.

What did all of that effort net? How does 720 naturally-aspirated horsepower at 8,300 rpm and 497 pound-feet of torque grab you? The engine was specifically designed to be used in the Riley Technologies track day car. We just like seeing it punish the engine stand and light its exhaust purple.”