Edis wrote:This engine is surrounded with myths and exaggerations. The engines were for instance not built using old blocks, but new ones, machined to reduce their weight.
The boost pressures cited are always given as absolute pressures, so 5.5 bar absolute is the same as 4.5 bar boost. This 4.5 bar boost was also only a flash reading during the 1986 Monza qualification. That engine didn't even survive the whole qualification lap. It was that flash reading that was the grounds of all the above 1300 hp claims (which in some stories have become 1500 hp). In race trim the engine didn't produce more than 600-900 hp depending on which season we're talking about. The boost pressure also increased over the years, up to 3.8 bar absolute (2.8 bar boost) in race trim. The turbochargers also changed from year to year and even race to race. The Garrett turbocharger used was also not a production item, but a turbocharger developed specifically for F1.
The Garrett turbochargers had several features that wasn't availible on production turbochargers. The impeller was for instance machined from a forged 7075 aluminum billet, having a design suitable for very high pressure ratios, including a transonic inducer. The turbine housing was cast in thinwall HK30 - a stainless steel that Garrett had previous experience with from gas turbine engines. The turbine was cast in IDM 5322 and electron beam welded to a shaft having a tri-lobe pattern for the fitting of the compressor wheel. So, these racing turbochargers were not your typical production turbocharger.
I read an interview with Gordan Murray and he talks about the engine and the ‘Hitler’ chips they used to fit during Quali. He states that the engine blocks were new, but then left outside in the yard for a year, before being prepped for racing.
