It's only my opinion, but I think you'd be better off with an EFIE than the Volo chip. I tried one and never could get any results until I switched to an EFIE. Mind you, I only tried the Volo on one car, and I know some others say they work for them, but I won't but another one.
1991 Plymouth Acclaim 3L V6.
1 dry cells with nineteen 6"x8" 316L ss plates, driven by constant current PWM set at 35 amps (13.3V at PWM). 28% KOH electrolyte. Total measured output 2.5 lpm. Mileage went from 18 to 26 mpg, all city driving (44% increase). EFIE set at .370 and I still need to play with ignition timing.