ORIGINAL: ChiDiddy

A lot of manufacturers knowingly do the wrong things to save face. I know plenty of companies that ignore "new' developments or improvements made by end users or resellers. Not sure what Saleens reason for doing so is. Much like the powerflash, it sucks compared to XCal2 tune, but they still do it anyway.

Why does it work better? from my own applications in the past, tapping the brake booster "works" and is the easiest to get to. But when you're wastegate, bypass valve, or whatever controls your boost level, it is dire to send it the most accurate vacuum/pressure source and not to split it with any major component that requires vacuum/pressure. In this case, its the brake booster. As the JDM site explains, the boost readings will not be absolutely accurate, therefore it will dump or take out an inaccurate amount of fuel per volume of air.