Oh no... sorry- I meant without using a wideband ON the ECU to control the fuel ratio upwards past stoichiometric during normal driving since the normal narrow band O2 sensor is really only effective between 14.0 and 15.0. I always tune on a dyno and on the street with a wideband sensor plugged in for fuel/timing map manipulation.
I'm more worried about a tuned ECU being able to maintain air/fuel ratios in the 17-18:1 range or higher while running on a narrow-band sensor. I've never tried to tune for that.
As far as boost tables, I could probably set the ECU to run lean with very conservative timing up to zero manifold pressure and hope to avoid detonation- then start tipping in the fuel to keep the engine from puking on itself.
I guess I'll just have to try it out.
Basically... I have all the tuning facilities and equipment at my disposal whenever I want to use them- and I want to modify as little of the car's configuration as possible to save myself some cash on parts. I'm sure I could add a wideband sensor to the car and hook up my Hondata S200 to really get the most fuel economy out of the ZC, but I'd like to sell the S200 and not have to convert up to OBD1 (which I really should) to do everything.
I can pretty much do the turbo install and tune on a non-OBD ECU without spending (or losing opportunity to gain) any cash at all... maybe I should just bite the bullet and throw in the Hondata and an OBD1 system to go for the best mileage possible. Honestly, the 50mpg goal is pretty minor compared to the overall scope of what I want to do to this car!