Rx8 operating temps (coolant temps)
 

Hi team, i thought i would make a thread to share and maybe discuss coolent temps. i also want to see everyone else temps as well if thats cool :-)

Im turboed:
Live in Florida:

My car seems to love running at 104 C (219.2 F) this is what im reading from my handheld microtech.

Im looking to get a new thermostat soon to maybe help lower the temps a little. Im open to other methods that can help.

Thanks,

Thermostat wont help unless your factory thermostat is faulty, it should already be fully open (190 deg I think). Are your fans turning on at the factory temps or earlier? I dont recal the temps the stock fans turn on at, but I would start by lowering them.

The FMIC is going to restrict the airflow to the radiator and can cause the car to run a little warmer under normal conditions. It will run a lot warmer during heavy loads (AKA race track).

Check to be sure the factory radiator foam is in place and doing its job (keeping the air from going around the radiator when over 40 MPH. Adding additional foam and sealing everything up around the radiator can make a bug difference.

Next if everything else looks good and the car still runs warm, I would install a secondary radiator. Basicly a small oil cooler (10X6X2) plumbed into the heater core system. You can place it flat on plastic underpanel and cut holes under. The air moving passed it should do the trick.

my fans should be coming on at factory temps but ill look into lowering them. i have an after market radiator and im also working on ways to better the air flow to the radiator. Great tips thanks man. do you know normal operating temps for a stock rx8??

220*f is kinda hot in my opinion.

My 04 would turn the fans on @ 212*f, then turn off at 202*f.
I installed a fan kit that turns them on @ 190*f and back off at 181*f. I haven't seen my coolant temps go above 195*f since.

I'm pretty sure the thermostat opens at 180*f cause that's what temp I sit at while cruising on a open road.

Please note the kit I use is not popular here due to the fact that the man who makes it apparently scammed a bunch of members here under a different company name. My own personal experience dealing with him was good though... Buyer beware.

yes i agree 220 F is pretty hot.

That is a big improvement, what does the fan kit concise of??

My coolant temperature while driving on the freeway is 83 - 84 degrees Celsius, according to the ScanGauge II.

It comes with a temp sensor that mounts to the small coolant hose between the thermostat and over flow bottle (near the battery), wired to two relays that replace your oem fan relays.

The part I like the most is the ecu still has full control of the fans. So fans still come on with the a/c or any other reason the ecu might want them on before 190*f.

Real easy to install too, took maybe 10mins. Paid about $100 for it in his eBay store.

o ok thats good i would like mine around there but the only thing is my intercooler block my air flow to the radiator and my freeway temps are around 93 C (200 F) if that.

yea ok sounds really simple. i noticed my fans are coming on a little late so thats something i have to work on or maybe buy the kit.

o yea also what are your in traffic temps ??

Depends on the ambient temp of course but I don't remember seeing mine ever climbing over 96 or 97 degrees.

o ok thanks

ok so i was looking at what temp my fans come on and it say it come on at 90 C (194 F) and the problem is they never came on at the set temp. what could be happening for them not to come on at the tuned setting?? i also changed the temp to see if it would work but it didnt..

Around the 83-86C is normal op temp for all 8's while driving.

THE issue is when at long idle or in stop and go bumper traffic while outside temps are @ 35+C.

What Mazda did with the Series 2 (and IMO the most important change was to have a faster 3rd fan speed for when coolant temps get around the 100+C.

S2 uses the exact same two Fan Blades as S1, but larger Fan Motors.

I know it is almost impossible to alter existing OEM Series 1 set up to have another 3rd or higher fan speed like the S2's, but you can at least set up a manually wired switch for fans constantly on (or use an access port) when in stop and go would go a long way.

Also look at your S1 Fan Motors, these have been known to slow down with age/use.

ok ill look in to upgrading my fans or adding one because my OEM fans dosent come on until temps are way too high, it seem like they come on when they feel like it and thats what got me messed up.

i have an handheld computer and i can change the temps the fans come on but the fans dont come on when i change the temps.

so i thinking my fans could be bad or maybe my sensor could be going on me...
im open to other theorys why my fans are not working correctly... plz share

in addition to the on/off temperature settings there are also hysteresis settings that alter exactly when they may or may not come on, this keeps the fans from continuously oscillating on/off around a particular setpoint

also IMO you would be better served to up your OMP rate at idle/low speed rather than dropping your coolant temp because this is only where these fan settings come into play, but I seem to be the lone wolf in this belief ....

How do you change the OMP rate on an otherwise stock -8?
Will a scangauge allow me to finne tune the OMP rates & fan temp settings?

Or do I need to "hack" the ECU?

I'd like to be able to fine-tune setting, without straying from the OEM hardware.

You'll have to change the corresponding parameters in the ECU program, via a Cobb AccessPort.

this is what you need:

this is something i can look in to, i just have to see if my handheld is capable of this function.

o ok

You need a Cobb AP to alter those values

:suspect:

Not at all. That is a very plausible approach.