Wheels24 reader Rory Nasson and his father Greg, from Athlone just outside Cape Town, are gearing up to take part in the 2014 Knysna Simola Hillclimb with two monstrous modified Audis.Nasson has written in to Wheels24 to tell us about their two entries for this year's event and also a bit about themselves....I’d like to introduce you to our two little monsters that we will be taking to race at the Knysna Hillclimb coming up later in May.GALLERY: Rory and Greg Nasson's modified AudisFirst is a silver blue Audi RS4, 4.2 V8 quattro with a 300kW *8-fogger nitrous and methanol injection which works on a programmable system. Our second 'little' monster is an Audi B6 S4 quattro with a twin-turbo V8 transplant from a C5 RS6 with upgraded turbos from K03 to K06. It also features a 300kW 8-fogger nitrous and meth injection. Both cars were built at Alspeed Racing Technology in Crawford.A BIT OF HISTORY...My dad has always been in the car racing scene back in the 'Indiana' days when he had three 3T 'Slant front' Toyota Corollas before the days of turbocharging and fuel injection... the days when 'sidies' was king.Later he started playing around with various conversions with Toyota's Twincam units including a 180i Twincam and 20-valve 'Wetlook' Conquest. Shortly after he bought himself an Audi A3 1.8T in canary yellow. As usual, the speed bug bit. That car was upgraded to push out 250kW from the standard 110kW. This became the race car and he then bought another Audi A4 3.2 quattro and that's when the quattro bug bit. A few months later he bought the RS4 4.2 V8. We decided to pit the 1.8T A3against the RS4 from a rolling start. The RS4 pulled a three-car length in front of the 1.8T which struggled for traction. It then came spinning pass the RS4 and continued to increase the lead when the RS4 caught up and passed.After that he decided to increase the power of the RS4 with a 300kW 8-fogger NOS system meaning the total power kicked out just over 600kW.Before we could test the RS4 against the 1.8T again we crashed the 1.8T. The motor was removed and transplanted into a Toyota Corolla 'slant front' which ran an 11.9sec 400m run at Killarney racetrack and hence was disqualified from the Street to Strip event.Eventually everything became too slow and we found ourselves chasing the 1000hp (746kW) mark on quattro. The B6 S4 was the perfect body strong enough to safely handle the amount of power we were looking for and research had us favouring the 4.2 V8 TT from the C5 RS6. We found a motor with a standard ABT-tune which came with 378kW, total power is now close to 700kW, if not more.McLAREN FIGHTER?Both S4 and RS6 were found in Johannesburg and we drove down to Cape Town where we did the transplant. The biggest nightmare was the wiring which we spent many nights redoing all the connections so that car and motor acted as one with all the standard equipment.The turbos on the RS were upgraded to K06 from K03 and is currently in the process of receiving an 8-fogger NOS system.The Hillclimb is the perfect event to test these quattro machines. We've been classed against a McLaren MP1-12CMy dad and I are in the horticulture and civil industry but our love for cars will always be huge in our lives... more so our love for the Audi brand. It's the reason why we affiliated with AR which specialises in modifications of all sorts of hardcore racing cars.*8-fogger nitrous and methanol injection = Usually cars have one nozzle which goes into the intake. These Audis have an 8-nozzle which means equal amounts of nitrous and methanol shoots directly into each eight cylinders.