Aftermarket thermostat?
 

Hi, I'm in the middle of freshening up my FD, V mount etc etc. I have been thinking of getting an aftermarket t stat that opens earlier, but I have also heard this will cause the car to think it's too cold? Is this true? I might mention that I'm gonna get an Apexi PFC as well.

Hope anyone has any input/experiences.

Thanks!

Stock is recommended. FC thermoswitch will help in a better way. (kicks the fans on earlier to keep the engine cool)

MAZDA already lowered the temperature of the stock T-stat from (IIRC) 88 C. to 81 C. back in the day. There's really no benefit IMO to getting anything lower, all it will do is slow warm-up. I think I remember reading about some aftermarket T-stats being sub-par in terms of gasket quality too.
As mentioned, a series 5 FC thermoswitch is a true plug-n-play for the FD thermoswitch and will activate fans on low speed at 95 C. instead of 108 C. But you can also adjust threshold temps for the fans with the PFC as well.

Does anyone have a part number for that 5s FC thermo? Or a link to an place where i can buy it, thanks.

I could be way off, but I believe this is the part he's referring to. http://mazdatrix.com/getprice.asp?partnum=18-8400-PN41

mazdatrix.com is a great source for oem parts

Ray Crowe, parts manager at Malloy Mazda [1-888-544-3400] is a well known and reliable source for OEM. And usually cheaper, even with shipping. If you prefer, just go to the local MAZDA dealer and get it using a part number or ask for a fan thermoswitch for a 89-91 RX7 turbo/non-turbo (S5).

But that looks like the right number. I show PN41-18-840, but Ray would know anyway. He's an FD owner and knows the cars better than most.

Thanks for the fast replys!