Mazda MX-5 Engine Problems

GOOD information. It's possible you are correct.

ANOTHER possible cause of the problem. One worth checking.

INTERMITTENT problems are always hard to track down, but I doubt it's the plugs or leads. I would be looking at the engine sensors and making sure they are working correctly. I would look closely at the crank angle sensor. That can cause a problem like the one you describe.

For road use I'd be happy with the 1.5 but, since you're going to be hitting racetracks, I'd definitely get the "big banger" 2-litre engine as it will be more rewarding to drive in those conditions.