*** it only drops that low once race-pace air flow is introduced on the cooler days AFTER the addition of the hood louvers. At idle or low speed driving in the paddock the thermostat operates exactly as it should. Temps comes up to 195*, thermostat opens, temp gradually rises to 205* or whatever the temp is that the fan comes on at a slower rate, fan comes on, temps drop to ~175-180*, fan cuts off, repeat.

Some Miatas were spec'd with a 195*, some with 180*. Mine has a 195 in it.

I appreciate you guys providing input that suggests my car is broken, but I assure you it is not. The only reason I posted in this thread was to advise the OP that the hood louvers were WAY overkill for a street driven car due to what I've seen with my car with the same radiator he was looking at getting. Prior to having the hood louvers installed and all else exactly the same the car would be right in the proper range of ~180-205* while on track as it should be. I added the hood louvers due to an assumed underhood temperature build up issue that I THOUGHT was present due to continually cooking my CPS on track. It turned out that what I thought was excessive heat build up and cheap CPS replacements was not the actual culprit as the cause was that the CLIP for the CPS was faulty. Put a new pigtail on and problem went away. However, I had already installed the hood louvers, so I can't exactly take them off...nor do I feel the need to source a different hood.

My point was that the hood louvers increased air flow so much that while moving at race pace, and ONLY while moving, during a cooler month event (March and November) then my car overcools. The rest of the year it settles in 10-15* degrees below target exactly as it should with the increased airflow of the hood louvers. This past weekend in particular was so cold in the morning that some of the Spec Miata guys were taping their radiators, indicating that they, too, were overcooling. I'm willing to bet that taping up my louvers will bring the temperature at race pace back up to 180-190.

At the end of the day I wish I didn't have the hood louvers as it was unnecessary money spent on top of being an unnecessary modification now that I have found the cause of my CPS issue. I simply did not want the OP to make the same unnecessary mistake I did. I'm sure I will, however, thoroughly enjoy the louvers if/when I decide to build for SPM S1 and/or NASA ST4 and add a heat generator under the hood haha.

If you are referring to my example, it's dropping from 190 to 150. I would agree that a delta of 140* would be majorly effed up haha.

Perfect. Also it seems that my choice of words makes it keep coming off like I think it's an on/off switch without intermediates - my bad on that part :inout:

And thanks for the info Quigs. It seems that the reroute + upgraded radiator + louvers would definitely be overkill for a street car. With this in mind, I was tickled with the thought of having the reroute with a stock radiator, and louvers. I do just generally like the idea of having the engine bay be cooler overall instead of being warmed by the stagnant-ish air.

Regardless, cost savings of getting the m.net glorified amazon tyc special - seems to be a moot point now that it seems the generic ~2" core aluminum radiators are "trusted" while being just $20 more. So it'll be that with contemplating getting a QMAX installed in the back with the engine still in the car. Any have experience installing that withOUT removing bolts off the PPF to tilt the engine forward to get more clearance during install? I fear that I'm not particularly secure in bolting it back (the PPF) in place with the right alignment, etc. afterwards.

I didn't mess with the ppf or anything when I did mine for the same reason. I ended up deleting egr because I couldn't get the pipe to fit. Maybe I would have been able to keep it if I had more space to finagle it but I'm on megasquirt so I just yanked it and blocked it. :bigtu:

Overall it wasn't that horrible, it took a whole day but I suck at cars so take that with a grain of salt. Two recommendations though, get a thin socket for the bolt that goes into the head it's a tight fit. Replace the heater core hose that connects to the housing. I about shit myself when it started leaking a day later, I was convinced I botched the gasket maker on the q-max and was going to have to pull it, but it was just the tired old hose.

It's easy to do without loosening the ppf. did nine in under an hour I just removed the heater hose and the coils.

You say you have a proper reroute. I would question that. I'm guessing the overcooling has something to do with the design of your reroute.

And to the other question, boats have an unlimited supply of cool liquid and use a thermostat to regulate their temperature. A properly working thermostat and water pump does not allow it to over cool or under cool.

Additionally, thermostats are not a binary device that are either 100% open or 100% closed. They can open gradually if exposed to a slow warming near their target temperature and close gradually as well. It is possible to have one just slightly open if maintaining and even temperature right near the opening value.

Perfect.

Sixshooter - I like the boat example. Good good.

Also - random question. Back in the day, there used to be a brand or something called "failsafe" thermostats (aka...when it fails, it fails open) - are all thermostats today, that way, now? Or do I need to specifically look for it to be called out?

Today's thermostats are generally reliable. Nothing is fully failsafe so check gauges on straightaways.

Anyone have a particular "favorite" ebay radiator vendor...on ebay? Thanks xD

I go with the cheapest all aluminum one I can find. Don't think I have ever used a vendor more then once.

xD damn shuiend.

I've had good luck with my CX Racing radiator, but its 5+ years old, so they've likely changed manufacturing plants since then.

Now I want to see a lake filled with thousands of boats until the water boils.

I’d recommend koyo 32mm and really any reroute, I’d like to see the new flying Miata one on a car to see if it worth it haha