So, we dyno'd Kim's car yesterday ('95 M3 engine, intake, exhaust, Conforti programming). The graph was very helpful, as it showed exactly what I'd suspected. The midrange A/F ratio was 14.2/14.4 for most of it, which is pretty fuel efficient, but not extremely conducive to power. Right up in the top end, it swaps over to about low 13/high 12 AFR, which is nice for power.

Basically, for most of the RPM range, it's getting good gas mileage, but could be seeing signifigantly more power... and that's what we'd rather see out of this car, especially at WOT.

Would a adjustable fuel pressure regulator solve this issue, or would that run it TOO rich at the higher RPM's? I'd like to drop the AFR into the low 13's for a majority of the powerband. I need to test the line pressure, if it's already pretty high (the stock FPR is 3.5 bar!), I'm thinking injectors might be a better decision. Would pushing more fuel to the engine be able to drop that AFR into the 13's, or would the DME compensate and cut it back? It's still OBD-I, so it's not overly controlling, but I don't know how much it can do in conjunction with the 02 sensor, as far as controlling that ratio.

What's the best way to achieve these types of results?