Coolant Temps
 

What are your typical coolant temps?

The reason I ask is because I was sure I put in a 180° thermostat. However I seem to idle to about 160-165°, and never seems to get anywhere above 172-175° during boosted runs and always settles back to about 165°

If that's the case then I did something right with my homemade scooper, but I take it either my thermostat is acutally a 160° model, or my easy therm settings are incorrect.

I have a 180* thermostat as well.
I see around 160-165 at idle in MT. Cruising with some light boost on and off i stay around 178*.
Yesterday I really got on it. Found a new neighborhood with houses being built in the far corners. It's my new wannabe racetrack. I got the temps up to 203* driving around that little "track".
Sometimes i think my Easytherm values are wrong but cruising with light boost staying around 178* makes sense to me. I don't have a scooper or anything but need one.

190-194 whenver the car is moving- cruise or boost. That's with a 180f tstat, 16psi rad cap and big ass rad. I've got the a/c condenser in front of the rad, with the IC and oil cooler stacked on top of eachother in front of that.

Anybody have oil temps in correlation to coolant temps?

180-190 while driving.

oil temps often do not correlate with coolant temps.

:nuts:
I've never seen an engine that didn't have fluid temps respond in similar fashion. As the engine gets hotter, the temps go up. When it cools they go down.

yes but oil temp will change quite a bit faster than coolant temp. When boosting for example, the oil temp spikes quite quickly before the cooling system brings it back down.

This is why people like external oil coolers, to prevent these temperature spikes particular to oil.

In a steady state case, yes the two tempeartures will show similar trends.

I just went and played some more. The weather is HOTTTT today. Hot for me anyway. It was staying right around 180* most the time but got up to 190* under heavier boost.

I guess I'm not working it hard enough :gay:

So are you guys saying your fans never come on? Doesn't the OE fan controlled by the send at the top of the thermostat housing come on at about 97C which would be about 206F.

I beleive that the link won't do any tuning until the coolant temp is at 80C which is 176F.

Something doesn't jiv :)

My fans come on around 180* when parked.

What are you using to read the temp?

MS, using the Factory CLT temp sensor you speak of....which is exactly why I'm unsure of my temp readings.

I to am using the stock sensor calibrated with Easy Therm. Also have been wondering if my temps are correct.

I know when looking at the coolant temp on the link I'll 97-98C when the fan turns on. So the temp switch at the thermostat controls the fans and the coolant sensor is at the back of the block. so this should be pretty accurate right?

With the MS and the factory coolant sensor don't you have to do some trickery to make it work? Maybe something is being lost in the conversion.

I'm just going off the information that FM supplies in their install and tuning manual. :)

Scott is getting his temp from the thermosensor in the back of the head. The sensor in the tstat housing is actually thermoswitch that goes to ground at 97c- which IMO is too late for a boosted car in the south. The link can control the fans though if you run a relay ground to the designated pin on the ecu (I did it per the manual). My fan comes on when the car comes to a stop - set to 95c (which I believe is the stock NA 1.8 setting).

Would be nice to see some oil and coolant temps from water/oil cooled turbos, and oil cooled only turbos.

I'd post my oil temps, but they're not representative of a working system. Either my sending unit is whacked OR my oil tstat in the sandwich plate (with cooler attached) isn't working. On my 3 hour round trip I was getting 270f at 3500-4000 cruise. Boost showed the same.

One guy had problems with his fans not kicking on. That is solved by removing a couple resistors which is what I have done.

I'm looking back at the Easy Therm setup and I don't believe I ran it correctly. I'm going to flash it and see what it looks like afterwards.

What easytherm settings are you using. Aussie Drivers adjusted ones or the others?

I think it may just have GM defaults on it now. I don't really remember to be honest, acutally I think i just uploaded the standard file, not the mod file by mistake.

with the mazda factor specs, i idled warm at about 160, with aussie's, i idle around 180.... I could have sworn the previous owner said he put a 160 thermostat in, not sure though. i hit 200 in boost.

The Thermoswitch the runs the fans goes to ground when 97C is hit. Couldn't you unplug the harness that goes to the thermoswitch and run 1L from the link back to this? Do you need to run a relay if you are just running the one fan?

I've got an oil temp gauge, and the sender is in the drain plug. Getting anything really meaningful from this is tough since it takes a long time for either the oil in the sump to get hot or the sender is REALLY slow. So I don't know if I could show a difference between boosted and none-boosted. I also think the oil pan does a pretty reasonable job at cooling the oil when driving. I can see my oil temps come up significantly when in slow moving traffic.

Also it takes a good 15 to 20 minutes to get any movement on the gauge, which starts at 140.

yeah hitting only 175º or so in boost doesn't feel right to me. I can't believe my little scooper is doing that good of a job.

Do your fans kick on at idle?

Me either, let us know what you find because i bet our temps are ~8-10* more than what they are reading in MT.

my fans are jumpered on all the time.

Yes you could, since you're just substituting the ecu for the thermoswitch ground- I've got a giant spal that pulls about 22amps on startup so it's got a 30amp relay. The real advantage of using the ecu is being able to control your fan points depending on season. It's far easier to keep the fluids from getting hot, than to try and cool them down after they've gotten hot.

My oil will be at 220 from a warm 180 if I make several boosted runs. Around town driving I see 240 - but constant hwy cruise shows 270f and that's just plain wrong for somebody with over 5 qts oil capacity and a cooler.

Should be easy for you guys to figure out. Unless modified the fan will come on at 97C. Is the correction you guys are applying with the MS linear? If the MS says you are running 80C when the fan comes on it should be reasonable to assume that you are 17C out.

Could rig a test light up to the thermoswitch to see when it is supposed to happen. :)

Maybe I'll run the relay just to be safe anyway :)

i'm heading out to do it now, then driving home, let you know in an hour.

ok, reflashed it correctly with Aussie's settings.


Reading closer to 170 after sitting for a minutes, low speed cruise I dip down to 160-165, if i sit at a light it hits 170 then peaks at about 175 when the fans turn on. so I'm going to assume it's good.

That means according to your MS the thermoswitch is turning on the fans at 80* instead of 97*.

All this fahrenheit celsius conversion crap is killing me. I'm simple minded sometimes. I'll load aussies settings, seeing how he has the same motor as me anyway.

Dammit it's a japanese car, metric is where it's at! :)

That sounds about right. I did the same thing for the first week or 2 with my MS. I was about 20-25° cooler than my VDO gauge was showing at the time.

Both sensors were mounted next to each other.

Tstat fully opens at 100c
 

I thought this was interesting. It's the OE specs for the FE tstat (my engine).
The tstat isn't fully open until 100C! I've got the fan coming on at 94c and shutting off at 88c. 100c seems incredibly high for full coolant flow to be initiated - no? Wonder if there's a spec like this for the Miata engines?
http://img253.imageshack.us/img253/3876/image002lv9.gif

Just for the sake of conversation, my car seems to run around 94-99* Celcius, per the Hydra.

Link reports back about the same for my car as well.

Remember that's FULLY open temp. It might be 75% open at 90. Only way to tell is to calibrate some hot water and test it yourself. Looks to be exactly the same in the 2001 manual...

https://www.miataturbo.net/forums/at...1&d=1178204464

fwiw, I loaded the rx7 defaults via easytherm and idle around 200 degrees ferenheit I see anywhere between 190 and 210 during driving

210F is typical for me for a 2nd-3rd-4th gear run (all the way to the redline in each gear). This is on a 95F day.

Jim

I get 212-ish easily/quickly while boosted, and the OEM temp gauge starts to go to "1-o'clock". I am around 196-205 at idle and cruising. Oil temps (temp probe in oil plug) around 240-ish after about 20 minutes of warming up.

So im guessing mine are wrong....I have Aussie Driver's EasyTherm settings burned into mine.

Fans turn on at indicated 185°F (85°C) and I cruise at 160°F (71°C), with a 180°F Thermostat.....

Easytherm didn't work out for me; it gave me totally messed up files. Better get them .inc files into excel and plot them, see if they make sense.

Jim

I pretty much settle in between 207-211, I got to 214 once while boosted. But I haven't made my top-of-the-rad shroud yet, which is bad becuase I moved it backwards. This is with the MSPNP easytherm settings.

hmmm I'll email jerry and see what values he's using.

tim- are your turbos water cooled?

My car settles in at 205-209 (there's no reading between 205 and 209). Factory spec for the thermostat is it starts opening at mid to high 180s, and doesn't fully open until 212. This is for a 94 with stock radiator.

-Mike

yeah after reviewing the factory service manual, the fans should kick on at 207°. My Easytherm values are off. I checked the resistance of my sensor and went back against the manuals numbers and they match up. So i gotta reburn it.

Did we determine that aussie drivers settings were good?
I was going to try reverants but am having trouble getting Easytherm to burn to megasquirt for some reason.
https://www.miataturbo.net/showpost....&postcount=104

Went for a drive yesterday and am sick of seeing false coolant temps at like 165 cruise and 180 under 2nd-3rd low boost run.

mine was an easytherm issue.

those values look way off, i use the factory RX7 settings. which should still be the same for you, unless there aren't ;)

2490 Bias

-20 16200°C
20 2450°C
80 320°C

the best way to tell is when the fans switch on. mine switch on at 210° indicated, 207° is the stock switch point.

Well guess i'll check that out with the fans tonight after practice. 2b continued.

Hmm, i tried to reflash with ET and ended up killing MS. I'm assuming it's a firmware prob right now so i'm gonna reflash the firmware.

As for the actual bias resistors on the board, if we are keeping the value of 2490 in ET, do we want to keep the resistors on the board. I was under the impression that if you were using any thermistors other than the GM units that you wanted them removed. But I don't know why you would keep the bias resistor values the same if you remove the resistors entirely.
I'm installing the GM IAT and i'm going to use the stock CLT sensor. So i'll use the RX-7 defaults for the CLT and use the GM defaults for the GM IAT sensor. I currently have R4 and R7 removed. I'm going to reinstall R7 (2490ohm) for the GM IAT though. Just not sure if i need the resistor to use the RX7 settings?

edit: Damn 9 volt batteries are ruining my day. I hate taking the MS out of the car just so i can install a POS boot jumper while using the STIM. Talk about PITA.

FWIW, I updated my firmware via Easytherm a month ago or so with the values that brain just posted up and it definitely seems to match everyone elses temps as I run normally around 205 - 210F idling on a hot day, 200-205 just crusin around real easy, and Ive gotten it up to 215-220 a few times while boosting hard for several minutes for tuning and just for fun too. The thing about easytherm is it looks and acts like its completely locked up when its loading and does not give any sort of meter to know how long it will take. I just let it sit for 10 minutes while loading and took a shit ... came back and it was done.

I used a wall power source for my STIM.

If you are sharing the coolant sensor with the factory ECU you should remove R7. IIRC it's R7 not R4, double check that. Otherwise, even if you have the correct ET values you'll see like 160° at cruise and a max of 180° or so.

Reinstall the correct resistor for the IAT however.


as for burning it. I've found that MS-II Downloader works much better. Create your _mod file with easytherm and then burn it with the downloader. Tends to freeze less. FWIW, there shoudl be around 1700 new rows written. If it only writes 325 then you need a new original file to start from.

You should *only* remove the bias resistors altogether if you are sharing the sensor with the stock ECU and both are using them at once. In that case you'd be using the bias resistor inside the stock ECU. See here for details if that's what you're up to:

http://www.megamanual.com/v22manual/sharesen.htm

Or search for my post on how to measure your stock bias resistor value ;)

I'm the one mentioned earlier who's fan didn't work because the ECU was seeing too low a temp.