Quote:
Originally Posted by ttimbo
Interesting chart, which confirms my concern to some extent. I'm ol' skool (not too old) so AFRs like this are, on first glance, terrifying. But so is the stock AFR plot. I wonder what a BMW tech would think? The chart also begs the question about exhaust gas temperatures (EGTs). I wonder if Evolve has a chart of these as well. If the tuned chart has higher EGTs (probably not all that much higher, actually) I'd be worried about the increased risk of turbo failure.
|
Got to remember that N55 is direct injection. By design, it's a lean-burn and EGT's are controlled within the limit due to improved fuel burn/efficiency. It may not act as true DI under WOT+BOOST but still have much improved burn patten within cylinder (think specially shaped piston and chamber top).
Regardless, I would hate to see mine M135i been run any leaner than stock with added boost. Risky endeavor without proper R&D.
Pending some proper ECU flash to come on the market. Piggy-back is a band aid. Cannot tap in to full ECU potential and adds some unnecessary risk.
There is so much untapped mid-RPM torque right there between 1500-4500
