I have recently installed a greddy FMIC koyo radiator and of course I knew going into it my temps would go up ( I also live in Texas which does not help things). I was running temps of around 180 with the fans on. Now in the heat when I am in stop and go I am see temps around 200-220. Am I pushing my luck? At what temp do I need to start to shutting the car down.

Thanks in advance for the info

 

The difference is the FMIC the air hits the IC first the A/C condenser then the Radiator. This the main problem with a FMIC

 

Ok, let's put this to rest once and for all:

There is no question that just about ANY aftermarket radiator is going to be "better" than the pos stocker in terms of longevity, but actually cool better over a wide range of daily driving? - probably not. Thicker is not better! It all has to do with the amount of air flowing thru the unit. Thicker units are somewhat handicapped especially if they are used on daily drivers - which about 90% of our cars are.
No doubt that the thicker units (Fluidyne and Koyo) are better for higher output engines driven at high speeds - with enough ram air to allow them to function they way they were designed. The Kansei at Mazda engineering built an amazing cooling system that works incredibly well IF maintained properly, the beancounters said
"let's save $3.00 per car and use inferior plastic for the end tanks. (Mercedes still does the same thing) Mazda was also obsessed about weight savings when they designed the FD3S. 10 years have passed and even now it still has one of the best power to weight ratios for a true sports car ever conceived by ANY manufacturer, - including the Porsche wizards to date.........

My OEM radiator with 75,000 miles on it works just fine here in Tucson with ambient temps of 103F and pavement temperatures of 170F - TODAY. Do I keep a close eye on it? sure....but until it goes it stays put since it works just great.

My engine temp at the BASE OF THE LEADING PLUGS? 190F all day long............. (I know since I have sensors there) Water temp is only a good "general" indicator of how hot you are actually running - and by the time you show overtemp on water you have already done metallurgical damage that has either killed your engine or dramatically shortened it's life.

If you are running much hotter than 190 to 200F you should probably consider ditching the FMIC for a high quality aftermarket SMIC to get some air moving again. You have a major cooling problem that will make your engine VERY unhappy. The differential in overall performance is minimal - although I do love the look of the FMIC's - especially on our cars!

 

Thanks for the ranting but my question has still not been answered. My car is not a daily driver, in fact I put about 1000-1500 miles a year on it. I just want to know what temp is too much. I understand cooler is better and when I am cruising on the hwy I do get temps at 180, but when in traffic I am see 200-210 range. Does someone know, I do know that the fans don't come on till around 210 without the A/C or parking lights on is this any indication.

Thanks

 

The low speed fans come on at 221F. If it doesn't go past that then you are fine. I'd be more comfortable if things stayed under 200F but the reality is the engineers designed the car to have the fans come on at 221F and they could have programmed the thermoswitch for whatever temperature they wanted. They felt 221F was a safe temperature, who am I to disagree? Common belief is that after 230F you're hurting the car and after 250F the engine is toast. So, basically you're fine. If you want them to come on lower, you can run with your driving lights on, this will lower the fan point to about 209F, or get a Miata thermoswitch, which I think lowers it to 207F. Either of these is plenty low.

 

Or, you can just purchase the Power FC and program them to come on at ANY temp, using Datalogit.

 

http://www.jt-imports.com/Billion.htm

Billion fan controllers.

I don't see any issues with running 200-210 degrees F.

 

Mmmm Datalogit
Steve?

 

Do the Fan mod..

3 dollar switch from Radio shack.
$1 for about 3 foot of reg old speak wire.
and a drill..

In traffic turn it on.
Before you park turn it on
will stay on for 10 mins after
you pull your keys out.
Save from some heatsoak.
But really great for restarts.
Temps drop like a rock..