I put a couple of thousand miles on a 4 gas exhaust analyzer adapted to run on a 12 volt inverter, on a road trip to and from a GM technical school up in yankee land from Tennessee. That's probably better than a dyno simulation. Two of us took turns driving while the other guy watched the readout on the analyzer. Light throttle with high intake manifold vacuum cruise produced A/F ratios in the high 14's- - - -pretty close to stoichiometric- - - - -which, BTW, means the exhaust emissions are only CO2 and water vapor- - - - -little to no carbon monoxide or oxides of nitrogen. Opening the throttle for hill climbing or passing richened up the ratio to 12.5:1 or so.
The test was run on an AMC Ambassador station wagon without a catalytic converter, with a dyno tuned, blueprinted and balanced 343 cubic inch V8 and a Comp Cams 260-H hydraulic RV cam, 9.5:1 compression, and slightly ported cylinder heads, running a Carter AFB 4 barrel and a Motorola electronic ignition system, on 87 octane unleaded regular gas, back in the early 1990s. The transmission was a Torqueflite 727 direct drive, and a 3.43 rear axle. Interstate cruise speed was in the mid-70 MPH range.
Jerry
