So what is "normal operating temp"? In C so I can read it on my PFC Commander

here is what i found from the temp gauge mod document:

Table 1. Temperature data for the 3rd Gen. RX-7

Condition °F °C

Normal coolant operating temperature 158 - 221 70 - 105
Fans turn on low (no ac) 221 105
Fans turn on medium (no ac) 226 108
Thermostat opening temp 177 - 182 80.5 - 83.5
Thermostat fully open temp 203 95
Pure water boiling point (0.9 bar {13psi} radiator cap) 246 119
50-50 antifreeze boiling point (0.9 bar {13psi} radiator
cap)
261 127

so based on this your in range i guess, but maybe want to go just a bit hotter so the car dosnt stay in warm up mode.

Well I removed my double throttle butterflies and have a PowerFC so I don't think it has a warmup mode now?
I'll let it get a little hotter though, thanx :-)

sure, just a suggestion/opinion, i have no hard facts on it

did you remove your aws system too? if so then ur ok, i have removed aws and double throttle systems too and it idles/runs great.

So how does the stuff taste anyway?

lol hahah :-)

Re: for people running Evan's coolant.... temps
 

Solution: Get a Koyo Rad.

I recently converted to EVANS NPG and I was seeing temps just as high as yours. My radiator was a stock sized regular copper radiator(not stock, it had metal end tanks). I think it must have gotten corroded and clogged inside because it wasn't effective at cooling at all.

I just installed a new 2 1/16" thick Koyo radiator. The difference is amazing! My temps on the high way are a rock solid 85 C with the A/C on high in 80 F weather. Before the installation of the Koyo I was seeing 105+ C and I needed to turn my fans on high just keep the temps below 100 C. Tooling around town I used to see 112 C, now I see 91 C w/ having to runs the fans on high.

Keep in mind that is a PITA to make it fit with a Large SMIC & Duct, but doable.

The Koyo is well worth the trouble and money.

I installed a malloy reman and converted to Evans NPG.

Temperature is 185 F at the filler neck with ambient 75F and in stop and go traffic.

Weird thing about this coolant is the ability to open the cap when your gauge is reading 220 deg w/o worrying about flash burn from boiling coolant.

I like this stuff already, knowing the head room available before boiling.

Install was straight forward with a reman: I vaccumed out all the old coolant and waited a few weeks before installing NPG. There was still some residual water as the the cap vented during the initial start.

Anyone know how critical it is to get all of the old stuff outta the system before putting new in? How about if you're not going to be changing types of coolant?

I need to do my AST soon, and would like to drain and refill my cooling system so that I'm 100% sure of the water/coolant mixture.

patrick

if ur not cahnging type tyhen its not exactly critical to get it all out....but if ur going to evens then yes, it is more importand and you will want to flush a few times with the sierra stuff to get all teh old stuff out.

More temperature data to report.

During initial startup, I must have residual air pockets in the system as the coolant temp at the filler neck read 240 deg but the PFC reads normal. The AST that I used didn't have a 0.1 inch dia. orifice either, thereby letting a percentage of the coolant flow thru the lower rad hose instead of the radiator. I installed a 0.1 inch orifice.

After 2 more start up and cool down cycles, I'm seeing 220 in traffic without the AC fan with ambient 75 degF. With the fan running, it's 180. I also drilled four 1/8 inch holes around the Mazda thermostat for increased flow.

Before installing the reman, I had the PFC set so that the fan comes on at 85 degC. However, it hasn't been doing this as the fan comes on only at 230 degF (due to the water thermoswitch).

Does this means the temp sensor under the oil pressure sensor is bad, thereby preventing the PFC from turning on the fan?

I'm also thinking of converting to Evans NPG. Anyone know how much, and where I can order this from? How many gallons do I need? Damien, how has this Evans worked out for on track?

Pineapple Racing sells it. When I installed it in my car, I just picked up a case, or 4 gallons. Its nice to have a little extra laying around. CJ

yeah, get an extra gallon or 2 in case you spill/leak some. I use evans in both my cars and like it so far. I have a very interesting story to tell that ill post a seperate thread on, evans may have saved my engine, but ill post on that later. I purchased mine from evans directly:

https://www.evanscooling.com/catalog/C_SrdForm.htm

I have a Power FC. According to Crispy Rx7, I'l need to readjust my Power FC's retard water temp from 110 C to 125 C via the FC Datalogit. Did you make this adjustment?

Manny,

your new avatar....ummmm do you have a "M" now!!! :eek:

anyways sorry to hear about the engine...I posted in the other thread. I was considering running Evans to help my warm up. I have a rebuilt engine, Ianetti 2mm, fluidyne radiator, 99spec turbos, pettit 170 degree thermostat, and asp medium.

On my break in, with highway driving, and no boost...I can BARELY keep my temps at 74 degrees C. In stop and go I hit 98 and the fans are already on full. It seems our cars are capable of staying cool...the biggest difference that effected my temps was the thermostat and the 99 front...more air seems to help.

Yes I have an '97 E36 M3 4-door in Cosmos Black with Gray interior. It's the ultimate driving SleepR machine LOL :)

The more I read about the Evans coolant, the more I think that my detonation was caused by a localized hot spot on the rotor housing, causing a temp spike, and pre-igniting the combustion mixture. I thought that heat-related failures were due to O-ring failures, but a high heat spike, could very well have been the cause for the detonation. I was seeing 115 C for a prolonged time at 12 psi @ Mid Ohio. Water coolant ratio was 80% distilled water, 20% antifreeze with Redline Water Wetter.

Read this passage from Evans https://www.evanscooling.com/main20.htm

I think I will switch to Evans NPG+ with the new motor rebuild.

nope, i did not adjust any of this stuff?

that is the biggest reason I run the stuff, supposedly no localized hotspots even when you get it really hot...by the time this evans stuff boils at some rediculous temp, you have other issues to worry about (like melting the entire car together ...hehehe), and again ill post more details on it later, but i had an occurance at the track recently that normal coolant would have not handled well and im sure would have toasted my motor, but the evans 'kepts its cool' (pun intended) and kep thte engine safe...more on that later...

Crispy Rx7 says the Power FC retards the ignition when the water temps reach 110 C. Power drops off. Not sure if this is true? If true, Evans NPG+ allows your motor to run hotter than 110 C, Power FC will retard ignition, and power will drop off. You'll need to readjust your Power FC to retard igntion at 125 C instead of 110 C??

Post the link to the thread.

So how much is this Evans NPG+ anyway?

ahh, ok ill check on the track car when i get a chance, but I definetly want it waiting till 120-125 before retarding ignition.

>So how much is this Evans NPG+ anyway?

go to the link i posted on where i putchased it (a few posts up) and you can see, it depends on the amount you get - $25 a gal, $22.50 4 or more gal

it may not look 'relativly' cheap, but you never really have to change it and compared to an engine going cuz of a hot spot, ..its REALY cheap!!!

evans story:

https://www.rx7club.com/showthread.p...12#post3302112

Ambient track temps Heartland Park Topeka 102 deg. F, Evans coolant at 12psi was 127 deg C(260.2 F). I have a pettit unlimited ecu, and the car ran perfect for full 30 minute instructor sessions all day long.(melted both heat tabs on housings).... That was 4 years ago and 27,000 miles ago. I no longer run evans npg(the temps got to me) but I fully support every ounce of the stuff. Keeping the engine a constant temp albeit higher, is much safer for longevity than is a lower avg. temp with hot spots hitting 500 or 600 deg. F. I now run regular antifreeze at a ratio of about 20%, distilled water 60% and Pro-Blend's Stops overheating mix. My track temps now are 230deg. F at 13psi at 100degree ambient. I can run full open at 10/10ths for full 20-30 minutes(30 minutes is pushing it though, I may have to do a cool down or two on the 30 minute sessions) and I run a cylinder head temp gauge in the rear housing hole that a knock sensor would fit in, metal temps are a cool 255 degrees or so. BTW, I also run a front mount Apexi intercooler and stock twins..... Vented hood helps tremendously as does a 16psi cap, and open thermostat(cut out the guts and blocked off the w/p bypass hole.)

FWIW:
Art