maybe 3-4 years ago when people were still running ms1...

 

Ouch, that was a little too mean brainy.

 

I'm just saying that's not a common post anymore, nor are the ait heatsoak issues we used to have to deal with, when we ran inferior MS setups

 

No worries. I can take it. Love my MSPNP, especially since making my AC idle-up firmware mod.

 

Did you check you oil level Jon ? At the August event I was getting hot too - well the car was and me...but anyways...I later found my oil level near the bottom of the dipstick, topped it off and much better - I assume it's sloshing around a fair bit...

 

The only other possible cause that i can think of for what you descrobe would be a radiator that has partially clogged water pasages that are hard to see and diagnose.
The fanns are running and the heater is the only thing that helps when you are not on the hwy, the cars are pretty old and who knows what coolant was there over the last 20 years.
My SC car runns cool on hot days autocrossing back to back w 2 drivers with just one oem fan ac condencer, WA heat exchanger (Koyo rad)

 

It could be like my old jeep where the stamped steel fins rotted off the impeller for the water pump...

 

After driving to the event, I checked the dipstick and found it was down 1/2 quart, so I filled it up. Also checked it right after the overheating to make sure there was no chocolate milkshake on the dipstick (blown headgasket dumping coolant in the oil). So, oil level was good.

I would be surprised if the oil level would make a difference to the cooling capacity. Oil temps might be a little higher with low oil level - which would be putting more heat into the coolant via the oil cooler - but your 1.6 doesn't have one of those!

I just ordered one of these, so hopefully will help: NEW Mazda Miata 90 97 High Performance ALL Aluminum Radiator | eBay

 

That is true, but the heater would not help much when idling and i would guess that the water pump was changed with the last t belt change not that long ago...

 

Well, I attended another rallycross event with my car yesterday. I installed the aluminum ebay radiator earlier in the week, and that definitely helped. However, the ambient temps were alot cooler yesterday (75F), and only one driver instead of two - so more cooldown time between floggings. In any case, instead of 105C, I was consistently at 85-90C. Yay!

Also won my class, and beat a bunch of Subarus in Prepared All wheel drive too.

Couple pics:










P.S. - There was no way the stock fans would fit in the car with the radiator as delivered. I had to cut the aluminum standoff spacers that the fans mount to by about 1/4" to get the fans closer to the radiator. Then, I had to cut off about 1/2" from the lower portion of the plastic fan shroud itself. It all fits, but there is only a credit card width between the plastic fan shroud and the 1-1/4 hollow racing beat front sway bar. Tight!

 

Well done Jon, I just looked over the results - man you were fast ! Congratulations !

 

Well, the course changed quite a bit between run groups in the morning, and then in the afternoon, it was getting grippier between run groups. So, its hard to compare times.

That being said, I was running at the same time as the horde of turbo Subarus in Prepared All wheel drive, and clobbered them pretty good!