Quote:
Originally Posted by Sony
3,000psi sounds about right. The DI system has to inject fuel into the cylinder at full compression at the top of the stroke when cylinder pressures are at their highest. That's how a DI system works...this is why the Direct Injectors have metal hardline's unlike the flexible fuel hoses of the port injectors, it's also why the DI system has a separate mechanical fuel pump as the electrical fuel pump in the tank cannot pressurize the fuel to a high enough PSI for use in the DI system.
For reference, Diesel engines have used Direct Injection exclusively for years. Diesels have compression ratio's on average anywhere between 16:1 and 25:1 and Diesel direct injection systems often operate at 25,000psi or more on the bigger commercial diesels.
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Yeah, quite familiar with the systems in general. My Speed3 runs around 2k PSI on an upgraded pump (1500-1600 is average on the stock pumps, which were notorious for going bad, but that's a whole other thing altogether...), so I was just curious where these cars sat on the stock system. I wasn't so much questioning 3k because it seemed high, as much as trying to gauge where my datalogging is at as I'm using a fairly unconventional method.