Back in September 2006 I ordered an Imola yellow RS4.When I finally took delivery in April 2007, it was the first Imola yellow RS4 in South Africa.Since then few cars have upset the performance car establishment quite like Audi’s RS4. The 4.2l naturally aspirated V8 engine produced 309kW at 7 800r/min. Good enough for a 0-100km/h time of 4.6 seconds and the World Performance Car of the Year Award back in 2007. Those oval exhausts emit a soundtrack which made kids drop their sweets in the sand too.Three and a half years (and 90 000km) down the line I have never once felt compelled to trade my RS4 for one of the newer Audi performance models. None these have the cachet of the RS4 though, just try and source one and you’ll see how treasured they are being nearly impossible to find second-hand... However, even the most committed petrolhead gets bored of the same thing day after day. It sounds bizarre, but I got tired of 309kW and 430Nm. I wanted something faster and more powerful but not at a ridiculous price.Nothing in the market tickled my fancy as I was not after a screeching supercar with no head room, but a four-door saloon with ample boot space.Super(charged) solution Then I found the answer. APR Tuning USA launched a supercharger for the B7 RS4 in June last year. Unproved and untested I was slightly suspicious and waited for the first RS4 conversions over in the States to see what would happen. APR Tuning produced mind blowing results of 427kW and 694Nm, trimming the RS4’s a 0-100km/h of 3.9 seconds. Those figures sealed the deal and Sportech South Africa imported the supercharger on my instruction. Working with technical guidance from APR USA, Sportech fitted the supercharger. The layout and design is of the highest quality, requiring no cutting or drilling of my RS4’s engine bay. All the APR parts just bolted or clipped into position. Every little detail was looked at with the intercooler sliding in just behind the front grill and the final supercharger installation looking as if the car was designed with its installation in mind. No crazy scoop on the bonnet was necessary either as the air intake via the front grille proved ample enough. When the day arrived for my first test drive I was nervous. Would my RS4 really feel that much more powerful? I got into the car, pushed the start button and the V8 supercharged engine jumped to a load thundering noise. "That sounds different," I told myself. Cruising out of the parking area onto a private service road I put pedal to the metal. The next thing I know the car launches like a rocket in 1st with immense force, hitting its 8 200r/min limiter with alarming ease. I change to 2nd with my gut now sitting on the back seat along with 690Nm. Second gear really shows the performance. All I can hear is this sinister whistling noise coming from the front and the thundering exhaust note from the back. I slow, gathered my thoughts and smiled like a boy that just got his first BMX for Christmas! I could not believe the power! A roundabout looms and I keep my RS4 in second gear, pressuring the throttle. What happened next I would never have believed – oversteer. The back came out like on a rear-wheel drive car and with the front pulling I corrected the beast and exit the roundabout with my heart racing and adrenalin pumping. Even though the RS4 Quattro system allows up to 80% of the power to go to the back, I never experienced that with my 'old' RS4.Awestruck, I stopped at Sportech with my hands shaking. "Is this my car?" I asked.