The popular way to add horsepower in the Miata world seems to be FI.
Turbo or Supercharger.
The stock motor is pretty stout and can easily handle 200hp with FI.
Stroker kits are more pricey and offer less performance upgrade over a bolt-on FI kit.
Check out
BR Performance
and
Track Dog Racing
for superchargers and
Flyin' Miata
for turbo kits.
FM also has a Stroker Kit but it ain't cheap.![]()