copyright Martin Spetz, David Lord and Michael
Text copyright Michael J. Fuller
|The 908's rear end packaging is conventional with no (as expected) surprises.|
the rear, pushrods operate torsion bars. A bell crank
the torsion pivot actuates the primary dampers which are mounted
either side of the gearbox. Roll and pitch is apparently
by the T-pivot which is located on of top the gearbox/bellhousing and
input from the same rocker as the damper.
We can also observe that the rear damper is running a high motion ratio. The benefits of this are higher shock velocities which in turn allows for more consistent dampening.
|A metal "shaft" looking very much like a anti-roll bar type spring blade, sprouts from the top of the T-pivot and is connected to the front of the bellhousing. It would appear that the structure in which the T-pivot mounts also has provisions to move, hence the spring blade. Note there are provisions for a second shaft to be mounted (to the left of the one pictured) allowing for the possibility of doubling one's spring rate. Given the orientation of the spring blade, it would appear to be set to full-soft, assuming left and right movement potential. For now packaging seems the primary motivator for this solution.|
|Rotational potentiometers measure angluar displacement of the torsion bar/bellcrank. You can just see the load cells as the heatshrink enclosed (frankly looks like a round of black electritcal tape) item just below the top of the pushrod where it locates to the bellcrank.|
|The radiator/cooler arrangement has the turbo intercoolers inboard (1), the oil coolers (2) next as we move outboard, and the water coolers (3) the furthest outboard. The water coolers exhaust out the vents in the vertical face of the sidepod. Note the aluminum intake plenums here.|
|The water coolers exit via louvers outboard. This louver panel comes in two sizes; full height or a half panel as seen here (Petit Le Mans 2009, lower ambients).|
|By Silverstone 2008 (though possibly earlier and shown here at Petit Le Mans that same year) the 908 appeared with carbon engine inlet plenums. And courtesy of an article in Race Engine Technology (and brought to our attention by François Terrien) we have a better idea of the purpose of the longitudinal swirls. They are evidently a continuation of the intake trumpet. At the tangency between the round plenum and the trumpet, the trumpet continues to rotate around the plenum in a helical fashion, through approximately 270 degrees, instead of dead ending perpendicularly into it. This allows for a much longer intake trumpet without the need to raise the height of the plenum to accommodate taller intake trumpets (thus keeping the trailing edge of the engine cover that much lower).|
|The rear wing pylons are attached to the rear end structure which is interesting for its obvious beefy aluminum construction. Similar items on the Audi R10 (rear wing pylons and rear end structure) are manufactured out of carbon. Seen here on the 908 at Sebring in 2008, these items appeared to be first iterations, even a year into the project.|
|By mid-season 2008 (Petit Le Mans here) the rear wing mounts and crash structure had morphed into carbon fiber versions.|