I have moved to South Dakota where they don't have any smog checks. I am also in the process of changing my '94 to an Italia by Simpson Design, with a supercharger. Things are getting very crowded on the intake side of the engine bay.

I have the stock ECU with a couple of add on, programmable computers for the extra fuel injectors on the blower. So I'm not interested in keeping it street legal in California.

Can I remove the fuel vapor recovery canister and its relay/vacuum controls? How about the EGR valve? Will the stock ECU tolerate those things missing, or not? How about the part of the intake system that has coolant routed through it? If I removed that, would the ECU compensate for cold starts by richening the fuel flow?

 

these urls will help you out with that.
Miata Turbo Forum - Turbo Kitten is watching you test compression. - Search Forums
https://www.miataturbo.net/race-prep...nly-car-50385/

 

thanks for the link, but those links are about chopping bulk weight only. My front end is already riding 1" higher than stock due to the lighter body. No, I haven't yet changed the springs.

but the real question is what emissions related sensors and actuators can I remove without totally screwing up the engine management?

 

You can remove the canister real easy. Just plug the intake mani and loop the lines. Whats funny is, the lines you loop, one goes into the sub frame and disappears and the other goes to the tank. The EGR and its associated bits will throw a CEL if removed. But you're supercharging so when you replace the stock ecu that wont be an issue.

 

Okay, thanks for the info on the canister. I'm a retired dude, and am more comfortable with carburetors than ECUs. Is there a different way to set the idle speed that doesn't involve routing vacuum and coolant lines to the IAC unit?

If I don't have a Cat converter either, do I need the EGR? Or does that mean getting a new ECU to avoid that hassle? How about knock sensors?

In short, what do normal race, non-stock engines still have in the emissions area?

 

Normal race non-stock engines have after market ECU's and remove all emissions equipment.

 

With the 94 engine you dont need coolant going to the throttle body for idle, you still need the air hose going to the idle control valve.

On my racecar, with a stand alone ecu, I have the egr blocked off and removed, no cat, and my evap line is cut at the back of the car at ground level and there's no canister. When I was on the stock ecu I just had the evap canister removed. One thing not mentioned in the canister removal threads is that the bracket it is attached to is bolted on and seam sealered on, just un bolt it and wiggle it till the seam sealer breaks.