From the RS2, Weber sourced the oil pan, camshaft, cam gear, intake manifold (treated to Extrude Hone), exhaust manifold and engine management system. It's clearly the long way around to building a more powerful engine. It breathes in via a K&N filter and exhales through a '91 quattro 20-valve muffler. The builder didn't offer any horsepower ratings, but with the components involved and the weight and traction of the Quattro, there's likely to be more than enough performance and dynamic skills on hand for most purposes.
Out of the box, Audi cars feature robust, almost truck-like drivetrains, and the stock gearbox was retained without issues of durability. An option, which we've seen done to a few Quattros, is to fit a six-speed gearbox from an S6.
Attention to detail was key to the building of this special Audi. After fitting the S6/RS2 hybrid engine, the car was sent to Craig Baranowsky Auto to have the tunnel reworked to fit dual catalytic converters as can be found on many high-end cars. Past the cats the exhaust gasses exit via '91 20V Quattro piping.
With the extra horsepower it was wise to improve stopping capability. Thus the stock brakes were discarded in favor of yet another parts-bin exercise. The front binders, with four-piston calipers, were sourced from the Audi Sport Quattro, a limited-edition model bred for rallying. Also known as a "Shorty" because of its short wheelbase, just over 200 units were built to comply with the Group B regulations of the period.
The rear brakes come from the aforementioned S6 and are vented as opposed to the original solid rotors. Clamping the rotors are S6 calipers, and German-made Pagid Orange pads (named so due to the color of the backing plate) are used on all ends. Pagid pads are used by many race teams and can also be found on many popular big-brake kits offered through the aftermarket.
Suspension mods are limited to a set of Eibach springs and Koni adjustable gas shocks. The stock Quattro 8x15-in. wheels, made by Ronal, were repainted and wrapped with ZR-rated Dunlop radials, size 225/50-15.
Interior mods included a general freshening and installation of an '86 dash bySewickley's Weber. The sound system was modernized with an Alpine CVA 1005 head, two V12 amps, six speakers, an Alpine Equalizer, an Alpine 12-disc changer, and an Alpine DVD navigation system. Too bad the car isn't painted Alpine white.
It's hard not to conclude that this sort of undertaking is not for the weak of heart or wallet. It is only though the dedication of a few devout Quattro enthusiasts that the legacy of this revolutionary car is preserved over time. As a card-carrying Quattro club member, no doubt Mr. Day enjoys driving his car at club events to further his enjoyment of a singular car, and the appreciation of fellow members.