Between 1999 and 2002 Zakspeed won the 24 Hours Nürburgring three times, with Viper chassis[36] C15 and C36. In an attempt to outsmart the 2003 24h rules in which the GTS-R was granted special admission as "Chrysler Viper 1.350 kg 90 Liter 2 x 30,8 mm (air restrictors)",[37] Zakspeed entered as Dodge Viper. In pit stops, they filled with more than 90 liters of fuel, were penalized twice and finished fifth on track, with 134 laps. Afterwards, they appealed at DMSB and were disqualified[38] altogether, with "Wertungsausschluss"[39] (exclusion from classification) for the Chrysler Viper. As the rules limited engine capacity to 6200 cc since 2005, Zakspeed converted the engine into a V8[40] of that size.