The question should be why do people think they're smarter than the combined engineering knowledge of every carmaker in the world. Can anyone think of a production car engine that doesn't have thermostat? There are no advantages to removing, drilling or coring the thermostat in a street car, only disadvantages. If your car's overheating, fix the problem!

And what's that got to do with the thermostat? Oh right, nothing...

Racers drill holes in their thermostats for a small improvement in coolant flow. They also don't need to worry about warmup. They also use chrome-moly, which is super-light but very brittle (requires frequent crack inspection and/or replacement). Point is: if you're not a racer, don't take your thermostat out.

i might have missed it, and i dont feel like looking hrough this thread, but i saw you said you were gonig to run Evans NPG?? If so then run a 0 lb coolant cap, im sure i saw you or someone say they were running a 13 lb cap. If your not running it then disregard.

Gonna run 7psi, like the Evan's site recommends. It keeps out water. 13psi adds unnecessary stress, but not any more than a normal system has.

I ran without a thermostat during my 'block seal' run. Put that thermostat back in. Get the factory mazda one. It is a big difference. My car starys at 1/3 or less no matter what. boosting with AC in 99 degree heat.

Ditto here, <1/3 w/ A/C, no matter how hot out it is, no matter how hard I hit the gas. "Use Mazda OEM thermostat only" should be casted into the neck above the thermostat. Or at the top of the forum's 2nd-gen FAQs. For all the headaches they cause, no one should ever touch an aftermarket (auto-store) thermostat. And I bet 90% of '7s have them.

I figured I want a gutted thermostat because I do have an N-Flo and underdrive pulley. I figure that n-flo is enough restriction to keep water speeds down. No actually proof of that though I was wondering if anyone had an idea on that.

I'll see 90 C most of the time sometimes 92 (194 F and 197.6 F respectively) with florida's 115 heat index and 80% humidity. With the N-flo, and a front mount blocking the air to it. I also have my heater core mounted in the brake duct. My friend get's the same temperatures with a non- N-Flo koyo, a bigger air blocking intercooler and no heater core.
Two gear pulls will put me at 100 C or 102 C for a good 15-20 mins of driving until they come down to 92 C again. (also have header wrap......)

Those coolant temps are being picked up at the sensor below the thermostat housing. Not the one below the oil pressure sending unit.