If you haven't already found this (plus comments) I'm surprised, but just in case...
Discovery Channel’s Time Warp series shows you stuff in super slo-mo, which apparently appealed to the ad folks at BMW Canada (really). So they trekked to Bonneville, set up a glass apple, some water balloons, and a bullseye mark. The resulting 2-minute video of the BMW M5, is on its way to going viral, so go ahead, add your hit.
It's pretty cool, actually. The “Bullet” video looks like a a tribute to the work of Harold Edgerton , a pioneer of stoboscopic phtography and a prof at MIT. The BMW M5 is said to be the world's fastest production sedan, powered by a 4.4L V8 twin-turbo engine. Top speed is limited to 155 mph (if you call that limited) but there's about another 40 mph in the box, if you can let it out.
The M TwinPower Turbo 4.4-liter V-8 is known internally as the “S63 TU,” (for “technical update”), a term that marks its evolution from the older S63 in the X5 M and X6 M. The 90-degree aluminum block is crowned by reverse-flow heads that draw induction air from the sides of the engine and exhaust it to the center, where the headers and twin Honeywell turbos lie in the block’s vee. Individual tubes supply each twin-scroll turbo with the exhaust gas of four cylinders—two cylinders from the left bank and two from the right. For each turbo, the respective firing orders of the feed cylinders provide equally spaced spurts of exhaust energy.
The new M5 is the first M to adopt Valvetronic, that meters intake air by varying intake valve lift instead of with butterflies (a backup throttle plate remains for crisis scenarios). Because of the bulky valve hardware and the limitations it places on engine speed, the M division has until now spurned Valvetronic. But BMW has downsized and lightened the components and reshaped the contact surfaces to make the S63 TU’s 7200-rpm redline, 200 rpm higher than the X5 M’s.
The turbo compressors grow by about 10 percent to generate additional volume and 21.8 psi of boost, a gain of 4.4 psi. The large boxes hanging off the front of the engine are the air-to-water intercoolers, closely coupled to the turbos to shorten lag time. They are twice the size of those in the X5 M to limit intake temps at a relatively chilly 131 degrees for higher air density and power. Direct fuel injection reduces combustion temperatures, so the TU’s compression ratio was raised from 9.3:1 to 10.0:1 to maximize energy yield from the fuel.
The X5 M’s engine banks are run by a single Continental/Siemens computer on the fire wall, but tighter clearances under the M5’s hood required splitting the box in two and moving the computers onto the engine itself—right next to the catalytic converters, in fact—so water cooling is used to prevent meltdown of the now-Bosch-supplied brains. The exhaust pipes running down both sides of the flywheel housing are 3.1 inches in diameter, 0.4 inch bigger than the X5 M’s, with double-layer walls to help contain heat.
Now check out the video.—Paul Duchene:
