The Audi engine started as a 2.3, and was destroked to a 2.1. The owner of the car did not reveal the internal specifications, not even what the rods were made of or how he achieved the de-stroke, whether it was longer rods, or any other means of de-stroking. Redline is set at 10,200 RPM. As I posted before 45 PSI, 900 HP, "Dynoing has been an issue, since it not possible to achieve reliable traction above 5800, and maximum power starts around 8000." And this is a street driven car, could almost be considered a daily driver. Sure you may have to rev the piss out of it to make any usable power, but you would have some serious bragging rights. I can scan the article and email it to anyone interested. It has most of the specifics on fuel system, drivetrain, exhaust, and intake set ups. Oh, BTW, the car reportedly cost $500,000 to build. Though carbon, and unobtanium were used quite liberally in the construction of the car, and he used an Audi IMSA racing 6 speed with custom ratios, so there is a lot of the cost right there, but the engine obviously cost mega$$$ to build.