> Those crazy Sweeds.
http://videos.streetfire.net/categor...64B8A395A5.htm
> Check out the engine compartment shots at the end.
It's not the Swedes. It's the factory, probably tyre testing.
But the engine bay is fascinating. It looks like very early KW (Sport) engine development. It's a Sport intercooler. It's obviously a 20V crossflow head - the exhaust side is pretty much 100% Sport. The head itself seems shallower and has almost accessible plugs. But there's no sign of an EFI fuel rail, so the injection system is a form of CIS. It's blurred in the middle, but the lumps pretty much correspond to a Pierburg mechanical analogue system. There's one fitted to a car in David Sutton's museum, though that one is reversed. If true, the "hose" that seems to pass over the forward part of the head is actually a Bowden cable feeding the wastegate position back to the metering head.
The Pierburg system is strange. It was designed for power boats, and Audi adopted it for the rally cars because of its design. To meet the legal requirements for power boats, a fuel injection system has to fail safe and allow the engine to run even in a worst case scenario - so the boat can be steered into the sea. This is great for rally cars, because it means you can make service even if it breaks.
It's breathtakingly complex to set up, even by ur-quattro standards. The "plunger" doesn't go up and down - it rotates, exposing triangular slits. The entire metering head rotates according to boost - a cam underneath moves a lever against rotation for inlet air temperature, and the whole bloody assembly slides down a track for rpm corrections.
The cam was changed for each stage of a rally. I think there are thirteen adjustment screws.
The characteristic whistle is because there is a gradual dump valve - the turbo runs at constant rpm (no spool up) and unneeded boost air is just dumped - inlet air is measured late for fuel provision in the Pierburg system.