where is your aftermarket gauge for the autometer located? i ask because if its up top next to the coolant cap, it can sometimes grab an arch of electricity and give you a wrong read. loosening the cap ever so slighty can remedy this, by that i mean less than a 32nd so as to not lose your coolant pressure.

 

you .2% off..... hahahha j/k

 

I mean...yeah...I guess 214F isn't bad. I don't think I would call it good either. I doubt it would be able to handle a road course either.

The undertray was like ?$158? and ray had to charge me somewhere around $30 shipping since its oversized.

The Autometer water temp sensor is in the filler neck right forward of the thermostat...about as low as I could go on the filler neck.

 

I installed a 16psi radiator cap for a little extra boil over protection. It's harder on the coolant system but I think its worth it while running conventional coolant. No leaks (yet).

I also replaced that holy 34 row oil cooler so I'm working with a pair of them again. Oil temps were 150-170F the whole time.

100F ambient and the fans set to come on at 95C (203F)

No AC - 92-95C (195-203F)
A/C - 96-97C (205-207F)
A/C after 0-100 mph blast - 99C (210F) peak
No A/C again - 92-95C (195-203F)

That's much improved. I've got no worries about daily driving it with the A/C on right now. I wouldn't want to try to road course the car in these ambient temps though.

The real test will be later this week...they're forecasting a high of 110F for Thursday. I don't think it'll be a problem.

After this week I'll probably make the switch over to NPG-R. We'll see though.

BTW...the stock IC sucks...66-78C (151-172F) air temps. Blah!

 

I had similiar temps. with me car but was easy to pinpiont the problem.
Autometer gauge 220-230f
PFC 190f (88c)
I just figured the guage is junk....try a new or better guage

 

Unless you are reading the temp from the same location (i.e. both sensor fairly close to each other), you aren't really comparing apples to apples.

 

Says the guy from Canada (all in fun there! )

My Autometer gauge and my PowerFC usually agree. About the only time they differ is when the PowerFC lags behind. The Autometer responds to changes much quicker. That being said all the temps in my above post are off the PowerFC (since that's what most people compare).

The temps may sound abnormally high to you but you have to understand that even (what sounds like) a small increase from 80F to 100+F will reveal practically every problem with your cooling system. The requirements go up rather quickly...especially in stop and go traffic. Alot of you guys in cooler climates that think you have your cooling system perfected would probably be surprised at your coolant temps if you were forced to daily drive in a location that topped 100F daily.

 

So...yeah after a few trips home in 104F weather and seeing 103C (217F) and hearing boiling after shutting off the car I'm definitely switching to NPG-R this coming weekend.

In the meantime I decided to do a little experiment. I pumped out 0.6 gallons of my 12.5% coolant mix and poured in straight conventional antifreeze to bring the mix up to 35% (the minimum the service manual reccomends). Well...bad idea. On the way to work this morning (80F) temps were slightly elevated from yesterday with the A/C off. On the way home from work (105F ambient & A/C blastin) I watched the PFC climb to 106C (223F) and sit there. As I said...I saw a peak of 103C (217F) yesterday in 104F ambient temps on the same drive.

Yep...that didn't work.

 

don't be surprised if you see higher temps with the evans.

 

Nah...I won't be. I fully expect it to run a little hotter in all but the coolest conditions.

I won't be a slave to the coolant temp any longer though. I won't have to worry about oil temp with the dual 34-row RE cooler setup either.

Anyone know if the A/C shuts of automatically at a certain coolant temp? Going thru the service manual I saw reference to a thermoswitch that switches at 115C (239F) coolant temp then switches back once coolant temp drops back below 110C (230F). It didn't say what it controls though. I wonder if that's it. I also wonder if that auto-shut-off will still operate with the Power FC installed.

I doubt I'll see 115C just tooling around town but I'm curious.

 

Sooo...yesterday I drained the block & radiator and sucked all of the old coolant out of the overflow. I filled it up with 100% antifreeze to absorb all the water in preperation for the NPG-R. Turned off the fans with the Power FC and let it heat up to 115C at idle with the radiator cap off & heater on to attempt to boil out what water was left in the system. Took it for a spin with the cap back on (no undertray) and it ran about 106C (no fans) in 100F ambient. Then I let it cool for a few hours, topped it off with more antifreeze, and let it sit over night.

This morning I used some foam from a local textile place and closed up the last holes I could find. Worked out great. I swapped out yesterday's 100% antifreeze for Evans NPG-R. If you haven't read about it yet it's mostly Etheylene Glycol based (Vs Propylene Glycol for NPG+) so the conventional (EG) antifreeze from yesterday should get along well with it. NPG-R is also noticably thinner than NPG+...this is supposed to help thermal conductivity although it has the same exact specific heat as NPG+ (strange). Lastly NPG-R is not a lifetime coolant like NPG+. It needs to be replaced every two years. Oh and 400F boiling point for NPG-R...like I'll ever need that.

Anyway I went back to the stock 13 psi cap because I don't need 16 psi with the NPG-R (duh). So to testing...99F ambient I recorded 97C solid on the highway (8 miles worth) with the A/C on at 84 MPH. I turned the A/C off and left the highway. While at 54-64 mph for 5 miles I recorded 93-96C. I thought that was AWESOME. Well later in the day I drove when it was 101F and it was 98C with the A/C on at 45-49 MPH. On my way home a few hours later it was 106F and I recorded 104C temps with the A/C on...same 45-49 mph with the occasional stoplight.

In all the above testing I had the fan activation temps cranked up to 115C...so no fans were on unless the A/C was on...and then they were on a lower speed (?medium?).

So 104C...not bad at all for NPG-R. I actually recorded 106C with the 35% conventioanl antifreeze when it was 107F on the way home from work Thursday (*fans on high too*). I'm finally happy with the setup. I may get a vented hood later to loose a few more degrees but that's just gravy.

 

got a situation for you guys..
yesteday out side temp was in the mid to hi 90's. dont have aftermarkiet water temp guage yet..but stock went to red and add coolant buzzer went off. ( i was parked when all this had happend)( think she was mad at me because i went to test an rx8) newayz..so i waited for an hour.. and added bout 1/2 gallon of water. waited another hour and started her up.no light/ buzzer. temps stayed normal.....drove for about 10 min to autozone to get collant. got 100% anti-freeze. (guy at the counter said since i had added water the mix wouldnt be a good idea. he asked my problem and it old him. he said i should try thermostat. so i also bought thermostat. and upon futher inspection. i noticed my coolant is the color of mud...( i know really bad). so my question to all you gurus
1. what is npg+/-r
2. where can i get the higher preassure rad caps and do they go on the filler neck or the ast.
3. when i install thermostat will i need to bleed system of air
4. to flush coolant can i do it my self or do i need to take it to shop.

i dont think there was any engine damage. (hope not anywayz). i hope i didnt hijack the thread but i figured iwas haveing similar problems.

 

Yes, you did hijack his thread...
1. Search.
2. The pressure cap goes on the AST. I wouldn't recommend going to a higher pressure cap seeing that your coolant is old; your hoses are probably old as well, which brings the risk of popping one.
3. Yes, you will need to bleed the system because you must remove a bunch of components to get to the housing, which needs to be removed for access.
4. You can do it yourself if you know what you're doing and you don't just let the old coolant run down the street gutter...

 

Tevor, your temps seem pretty close to what I have seen in my car. So far this summer my car has reached 97C driving hard around town with no A/C. I don't remember my car ever getting past 99C with the A/C on around town. On the way to Sevenstock a couple of years ago my car got up to 106C driving trough Palm Springs up a hill (scared the **** out of me). I think it was like 115 that day I have a stock radiator, no foam ducting, distilled water, coolant, and a bottle of Water Wetter. I have a crank pulley and the Greddy underdrive pullies so I don't know if that makes a difference. Let me know if you ever need my car to compare temp differences. It may make an interesting comparo.
Scott

 

Another thing to consider is a miniature battery. After installing an Oddyssey PC680, I can now see my radiator in the otherwise-stock engine bay. I'll post photos once I finish building a proper tray for it.

-s-

 

Trevor & fdeeznutz I'd also like to compare temps with you as welll. I live in El Paso, TX and were're getting temps up to 109. On that day my highest temp reading was 96C. Funny thing about my car is that in stop and go traffic it gets cooler, about 89C. On the highway about 94. What I have noticed is I am getting some turbulance from the fans. I feel the fans blowing air through the radiator but I also feel some air being blown back towards the noise of the car while at idle. Both fans are working and spinning in the correct directions. I believe its the air hitting the air box and battery box thats causing the turbulance.

 

Scott - no higher than 99C with that setup? That's remarkable...about as good as it could possibly get with that combo. As I said before 102C-106C was the norm for me with what should have been a superior setup. My car's on crack...

Man...speed and ambient temp plays a huge role in things. I have the fans set to come on at 106C (pretty much guaranteed I'll be at a stop to see anything over 104C).

Taco Bell drivethru with the A/C on max in 104-105F ambient: 108C (223F) stable (it dropped down to 102C as soon as I got back on the road)

Drive home at 11:30 PM (86F) at 49-54 mph getting on it every now and then: 85-86C (185-187F)

 

Obviously not a solution for you guys, but I was wondering would putting in a single turbo and eliminating all the stock airbox stuff and relocating the battery help reduce temperatures by creating better flow in the engine bay(less plastic and such) and lower by creating less heat? (one turbo instead of two)
Im really starting to worry and will do just about anything at this point

 

I have stock motor, stock turbos, stock radiator, stock radiator caps, stock thermostat, stock pulleys, stock everything except for the Miata thermoswitch. I built simple metal fences inside the nose that seal the sides of the radiator opening to the sides of the radiator. I removed the stock plastic air deflectors in the sides of the radiator opening; this makes the inlet larger. I run a coolant mix of 80% water/20% coolant in the summer.

This weekend in 95+ degree weather I towed my fully loaded tire trailer down the highway at 80-85mph for over 4.5 hours each way. Car was also loaded with luggage and a passenger and the a/c was on max the entire time. Coolant temps ran at 185F, rising to 190F if I was following closely behind another car. In stop and go rush hour traffic temps would climb to 195F.

Doing nothing but running a higher ratio of water to coolant will make a nice difference. Sealing the inlet to the radiator makes a huge difference, especially in highway temps.

 

I've got no undertray, no side sealing, an FMIC, and a stood up Koyo radiator, with greddy pullies, and a B&M Hi-Tek Supercooler (has a Spal fan on it) And in the worst of traffic it will hit 100C then get right back to 94C.... On the highway it runs mid 80 C.... Never touchs 90's unless you start getting on it, and even then it's low 90's.... But we also don't see 100 degree F days in SC....

 

Damon,

can you post some pictures of your handi-work ?

:-) neil

 

That's strange. I have koyo, and 2 row FMIC. Daily driving in San Diego my temps would be in 93-95c on the PFC. Whenever I sit in gridlock (everyday) I would turn on the AC and my temps would drop to 87c?? I think you should look into a vented hood. I know it makes a difference.

 

Just wanted to post my latest change for future reference. I re-wired the fan control circuit to have high speed only...actuated by the PowerFC/datalogit at 97C. So far things have been great. Granted its only been 93-95F lately but if there's not much airflow the coolant hits 97C then the fans crank up and instantly drop the temps down to 93-94C...air on or not...stop and go or not. It doesn't seem to matter. No more trips to 100+C like before.

I dumped the AST BTW...and I'm still runing NPG-R & a 13 psi cap too.

 

Why don't you have the fans come on at 86 C? I have set mine to come on at that temp via my datalogit. I lost a motor to coolant seals before and am not taking any chances with cooling.

I usually see temps of 85-86 C or less.
Koyo
Evans
0 psi
Underdrive pullkeys
Fans on at 86 (is this too low???)

 

fwiw, my fans are set to come on at 86, 87, 89.

I'm running a Koyo with a Greddy FMIC and Evans. In stop/go rush hour traffic in the July, August NY area heat (90 degree high humidity), I would see temps in the high 90s and occasionally would hit 103ish.

Most other times when the car was moving, I'd be in the 86-89 range.

I believe what is killing me is the lack of any ducting due to the FMIC and Radiator setup. When the car is stopped, the fan just pulls the hot air from within the engine compartment back through the radiator. FMIC guys especially ducting sealing the top of the radiator to the nose of the car and along the sides as well. maxcooper did something to this effect. there are some pics in the single turbo section.