The car came into the garage with just a mild tune and downpipes, but big things were on everybody’s mind. After all, the RS6 is not just a standard Audi; it represents the culmination of years of engineering know-how and an ever-present quest for a more powerful yet refined vehicle. Not since the legendary Quattro has an Audi inspired both awe and fear at the same time. In keeping with this knowledge, Fluid MotorUnion set out to build a car that would command both respect and applause at every angle, and so far, that’s what it’s been doing.
The first round of modifications were geared towards more a “behind-the-scenes” aspect, with larger intercoolers for the turbos and upgraded charge pipes, intake and exhaust manifolds. The manifolds and charge pipes were treated with the Extrude Hone process, which is a powerful polishing treatment that allows air and other gases to flow as smoothly as possible, increasing power and reducing parasitic loss. In keeping with the notion of reducing horsepower loss to outside factors, Fluid chose to coat both the intake and exhaust manifolds with Swain Tech’s thermal coating, keeping the heat in places it should be and away from the places it shouldn’t. Adding some extra power was the next step, so we decided to port and clip the stock twin turbos, allowing the turbine wheels to spool faster and produce boost more efficiently. We also got some pretty nice wheels for it, 19” Rennen R10 concaves, with our shop name on the wheel itself, and the owner’s last name initial on the center caps.
And then, sadly, the stock RS6 block decided to bite the big one and depart to engine heaven. So we ended up sourcing a much stronger short block. The new block featured forged internals (rods and pistons), with a compression ratio of 8.5:1 (down from the stock numbers of 9.5:1). From this excellent starting point, we added a Cometic head gasket and a relatively large collection of ARP parts (head studs, rod caps, everything we could get to fit). At this point, the goal we had was to ensure the longevity of this vehicle by creating an engine capable of withstanding power well beyond its current capacities. For the rest of the RS6’s build, this has been the mantra – if we build it to ridiculous capacities, then all parts should function normally at power levels well below capacity.
From this point, OJ went to the Middle East for a couple months. Almost immediately upon his return, the RS6’s ECU had shorted and fried part of the wiring harness, which were replaced by the dealer. In terms of setting up the tune on the new ECU, we went through three tuners that promised results but failed to deliver those results. Once the tune finally stuck and things were going well, we worked on managing the boost from the twin turbos, as both turbos would drop out of peak boost well before redline. The solution to this problem was to add a boost controller, which would hold the pressures steady up until redline. This worked, but the high boost started eating up valve covers; we went through three valve covers until we realized the problem lied in the crankcase ventilation. This meant the solution was as easy as fabricating a new oil catch can, which sat atop the valve covers and added a nice aesthetic touch to the otherwise utility-driven engine bay.