Does OBD version matter when turboing?
 

I've been wanting to get an NA Miata for a while as a project car. I plan on turboing it later down the line and was wondering which 1.8 NA is better for turboing. The 94-95 or 96-97? I live in California so I gotta worry about smog and all that. What are the differences between turboing a Miata with OBD I and II? How will emission tests differ between the OBD I turboed and OBD II turboed? I heard you can "piggyback" an ecu on obd II cars. How does that work?

skipping explanation....if you plan to stay in that state, then i think the Flying Miata Kit is your only option to stay absolutely legal

Does that kit not require an aftermarket ecu? If it doesn't ,any 1.8 NA will work?

What does the product listing say?

For California it makes no difference, you will never pass visual inspection with a non carb legal kit.

The only kit on the market that is carb approved is by flyin miata.

/end of thread.

94-95 would be preferred. I believe 96-97 has to pass sniffer, visual, and OBD test, and 94-95 is just sniffer and visual.

The FM kits have CARB numbers for ALL years.

It won't matter. Not for smog. Not for performance.
And here in Texas, I'd rather have an OBD2 car, since they'll just plug in and check for readiness lights/etc.
Since I have an ODB-1 car, it has to go onto rollers. No "sniffer" for ODB-2 here in Texas.

How would you turbo an OBD2 car in Texas? Limited to same FM kit?

I suspect they'd put you on the rollers too, but I can't say firsthand.

Right, but with obd2, it needs a lot of stock components installed in order to have those readiness codes. It’s much easier to tune a MS to pass on the rollers with giant injectors and a turbo.

This is my goal, piggybacking the OEM ECU or swapping back and forth annually sound like a major headache. The only equipment they check for here is your cat, and high flow units are cheap. You can always whip up a none of it tune. On my old Taurus SHO you coild disconnect the timing connector to run base timing with no light and get a clean bill of health.

I sense thread drift here.

OP is in California. You're pretty much stuck using the FM kit with Voodoo Box if you want to stay CARB legal. Or the Fast Forward Supercharger (FFS) kit.

Other states, your results may vary.
If you need OBD-2 codes to be returned in YOUR state you'll have to use the stock ECU during smog/inspection times.
Is it possible you can request a sniffer/dyno/roller instead? Anything is possible but the best thing will be to check with your local smog shop.

Everyone gave California a load of grief on their CARB stuff... but I suspect most states will end up requiring similar things, including needing OBD-2 communication with your car. Megasquirts/AEMs/Hydra/etc won't do that.

So, be prepared to swap every two years. Small price to pay labor wise IF you want to double your horsepower. Very small price.

What about the 04-5 Mazdaspeed? Any advantages?

Best you can hope for is the Little Enchillada kit from FM or the equivalent.
Once you remove the factory ECU from the equation... well... you'll need to look into the smog laws in your state for details.
If they require OBD2 codes to be returned, then you're out of luck.

On the MSM I supposed you might be able to pull the wastegate line with a larger turbo for whatever is required during the smog test/checks, but you'll still be swapping out ECUs to get those codes for the test.