Reuben -

I don't know what sort of MAF is on the Stealth engine.

The Gen1 ECU does a pretty good job of retarding timing under load. <img src="/forums/images/graemlins/cyclops.gif" alt="" /> In NA form and with a healthy engine and good gas, I don't think you'll ever hear a spark knock from one.

A boost-dependant rising rate regulator provides needed fuel under boost by increasing fuel pressure, which in turn increases fuel supply without the ECU knowing why - only that the mixture is ok for the operating parameters. On a lean o2 sensor signal under boost, the ECU doesn't know that fuel pressure has increased and keeps increasing injector pulse width (if necessary) until the lookup table is maxed out or the injector goes to max flow. The trick is to choose an injector size that gives good idle characteristics, yet can deliver enough fuel without asking the ECU to exceed the imbedded range of lookup tables in the chip. It's up to the tuner to find/adjust the rate of fuel pressure increase that satisfies the mixture over the boost range - a blend of injector size, base fuel pressure and rate of pressure rise with increasing boost. I'm no forced induction FI expert either, but I'm about to start school on my system.

Frank