V8 Miata emissions testing

I was having a chat with trickyrix last night about a V8 NB and how such a creature would be treated at our local emissions stations.

Given the plug-in nature of the OBD2 testing, how would the owner of such a car get it to pass this test? Would the car be tested as if it was the donor of the engine (assuming for a swap of the harness & computer along with the engine), or can you just ask for a sniffer test on the rollers? Maybe keep the stock computer as well, along with some basic sensors so that it thinks it still controls the car?

It would be tested by the year of the motor unless the motor was older than the car. If the motor was newer they would plug into the OBD2 port and test it that way, (which is easy to pass with the right tune) and only roller it if the motor was older. If they plugged into your miata computer it would fail because none of the sensor are used.

Just an FYI.

On the V8 powered Miata Gary brought to Kellers a few weeks back, the car used Miata electrical for all the external wiring such as lights, wipers, etc but had the Corvette's stock ECU under the dash handling engine management and had the GM OBDII plug available to plug into for emmissions testing and engine diagnosis.

in my experience with VW's, they just plug in and get a readiness code or not.