Evan Wrote:at track speeds in open air, even an original miata cooling system should keep the car nice and cool.
Going 70/30/WW may band aid the problem but it sounds to me like there is something else going on.

Thermostat is cheap to replace but they are designed to fail open, i doubt thats it. (and if it failed closed it would have pegged the temp)

Was the engine detonating at all? Rocks in a can?

can you check/set timing on the 99 engine?

PDenbigh Wrote:Check the ignition timing (and all the things that affect it). If it's off or erratic, it could cause you to lose power and cause the temps to go up. I assume you checked your coolant level after all of that, right? Don't want that to boil and get low.

Are miata temp gauges "accurate" or are they more binary? Most modern gauges are either "in the middle" or "high" by design, and don't really accurately display medium-to-minor changes in temp. ("accuracy" freaks common drivers out, ("it's always moving!!!") so they took out the fidelity. On a RX8, for example, I've heard that if the water temp shows "high," it's already too late. Just something to be aware of.

I finally fixed the cooling issue on the XR this weekend - with a higher pressure cap. 28-32psi rated cap, up from 22psi. Temps never got above 200 at full boost Saturday or Sunday, and would quickly fall back down to 180 as I came off the track into pits. My trouble symptom was that it was boiling all of the water out, which doesn't seem to be your issue.

Miata.net about Temperature Gauges Wrote:The stock water temp gauge on the Miata in a way is linear. It's just that between 180°-210°F, it will stick to that 11AM position. If you ever climb over 210°F, you will notice the needle will climb up slowly. At about 210°-220°F, it will sit at the 12 oclock position. At 230°F, you can see the gauge start to move to the 1 or 2 oclock position.

JPolen01 Wrote:You've now made NASIOC twice in non Subarus. You are internet famous. <!-- m --><a class="postlink" href="http://forums.nasioc.com/forums/showthread.php?t=2531160">http://forums.nasioc.com/forums/showthr ... ?t=2531160</a><!-- m --> ...Beware of OT.

Jake Wrote:I'm using the 95's Cam Angle Sensor - someone said the 99 motor should set timing automatically (versus the NA's motors where you can advance it manually) but I don't know for certain.

PDenbigh Wrote:Are miata temp gauges "accurate" or are they more binary? Most modern gauges are either "in the middle" or "high" by design, and don't really accurately display medium-to-minor changes in temp.

navin Wrote:Stock radiator? If so I had the same type of overheating in the Civic with a dual-core OEM radiator, swapped out to a blingy aluminum one and it cools just fine now.

You can pick up the cheapo ones on ebay and they work just fine, Mishimoto or whatever. I never had much luck with the water-wetter combo to be honest, car still over heated.

ScottyB Wrote:so it sounds like the cooling system isn't the problem, but maybe a symptom...good rad, good coolant, thermostats fail open, and you're making stock power. i wonder if it isn't something weird like a clogged cat. did you notice any weird smells (like metal cooking) or any really intense heat coming up from the floorboard? when you first ran the car after the swap, was it running over-rich or anything like that?

if the cat was clogged up it would certainly prevent you from making power (either through the physical breathing problem or the ECU retarding timing like whoa) while also keeping the engine from evacuating a lot of hot spent gases - i wonder if that in turn would cause a heat soak of the entire engine, ultimately leading to the cooling system struggling to keep up.

new water pump went in with the swap, yes? metal impeller or plastic? if you lost an impeller fin i wonder if that would hinder circulation.

CaptainHenreh Wrote:Can we please start it off with a picture of Feersty's chrome hubcaps?

JustinG Wrote:Or his Krylon fog lights