▁at ▁the ▁ ▁in ▁ 1 9 8 5 . ▁ ▁Some ▁Cos worth - using ▁construct ors ▁developed ▁their ▁own ▁engines ▁in ▁house ▁during ▁a ▁Grand ▁Prix ▁season , ▁such ▁as ▁John ▁Nich ol son ' s ▁Nich ol son ▁Mc L aren ▁operation ▁or ▁Williams ▁F 1 ▁using ▁John ▁Jud d ' s ▁work sh ops ▁to ▁u pr ate ▁the ▁standard ▁ 4 8 0 ▁B HP ▁that ▁the ▁D F V ▁was ▁producing ▁in ▁the ▁late ▁ 1 9 7 0 s / ear ly ▁ 1 9 8 0 s . ▁U pr ated ▁p ist ons , ▁cam sh aft s ▁and ▁val ves ▁meant ▁Williams ▁and ▁Mc L aren ' s ▁D F V s ▁were ▁producing ▁over ▁ 5 1 0 ▁B HP ▁at ▁around ▁ 1 1 , 0 0 0 ▁R PM ▁by ▁the ▁early ▁ 1 9 8 0 s , ▁which ▁meant ▁the ▁power ▁def ic it ▁to ▁the ▁tur bo charg ed ▁Ren ault s ▁and ▁Ferr aris ▁was ▁only ▁around ▁ 3 0 ▁B HP - 4 0 ▁B HP ▁in ▁race ▁trim . ▁Since ▁a ▁D F V ▁only ▁needed ▁a ▁ 1 9 0 ▁lit re ▁fuel ▁tank , ▁compared ▁to ▁the ▁ 2 2 0 + ▁lit re ▁s ized ▁fuel ▁tank ▁required ▁by ▁a ▁tur bo ▁engine , ▁it ▁meant ▁the ▁power ▁to ▁weight ▁ratio ▁of ▁a ▁Mc L aren ▁MP 4 ▁or ▁Williams ▁F W 0 7 / 0 8 ▁with ▁their ▁special ist