NotAPreppie

Whatever makes you feel better.

redcivic

Well you seem to have your mind made up based on your unscientific "results". That is cool, but it doesn't mean much honestly without presenting data that was taken in a controlled manner. Science is great because it is facts based. But if you are happy and it gives you peace of mind then that is cool.

TheClemsonFan

95-100 ambient temp with the ac on both before and after the mods. Except when the coolant temp went above 210, then the heat was on.

pistonhater

Some of you think you know something about driving an RX8 in hot weather. Well, Unless you live in Arizona you don't know anything about heat

Temperature is in the triple digits here from May-September. And when I say triple digits I'm not talking about 101 degrees. We are talking about 110-115 easily...every damn day. There's a few days during the summer in which it goes all the way to 120 degrees. That's HOT my friends.

I do not have any of the aforementioned cooling mods. But this is what I've found in my car after careful observation of my obd2 reader in various conditions:

-Normal highway cruising - not spirited - UNDER 3,500 RPMs (which comes to about 68-70 MPH i think) my temperature is a consistent 198-202 degrees. That's actually not bad with a 115 degrees outside, right?

-BUT, that's with the AC OFF. The moment I turn it on, the temperature goes up 10-12 degrees immediately, so that brings the cruising temp to the 208-214 degree range. That might not that bad, but I do not feel comfortable cruising through the desert at that range for hours. So I keep the ac OFF to bring everything down to the 198-202 range for long trips; it just gives me peace of mind.

-If I redline the car anytime after 10am, the temperature goes up to 118-120. That's almost a 20 degree jump from the original cruising temperatues. So during the summer months I do not redline the car in the afternoon LOL. The fun driving has to happen in the morning for sure.

If any cooling mods would allow me to use my AC during the summer by keeping the cruising temperatures consistently below 200 degrees with the ac ON, then I would do it. It would be nice not having to sweat my *** off during long drives across the desert when it's 115 degrees outside.

redcivic

It gets plenty hot down here and with a lot of humidity which is an important factor.

And sure adding more capacity to the system with a larger and more efficient radiator, more powerful aftermarket fans, functional vented hood, etc. does definitely help. But not the things listed in the thread. One guy in NZ has even relocated his AC condenser.

NotAPreppie

Humidity is only really a factor for evaporative cooling systems. Heat index is mostly about how much hotter it feels when sweat isn't evaporating off your body.

Radiative and convective cooling systems don't really care that much about humidity.

Also, another thing to keep in mind is that the S1 water pump isn't good at high RPM. Over 7000-ish RPM, it cavitates and starts churning water in the pump housing rather than pumping it. If you spend a decent amount of time at high RPM, it might be worth it to upgrade.

redcivic

My understanding is that humidity in the air reduces the thermodynamic potential of the air. Basically the water vapor in the air absorbs more heat.

As for the S1 pump (upgraded at some point with a different impeller at some point) versus say the Mazmart pump, I think the thread with the simulations ran on both pumps has some interesting data and discussion.

gwilliams6

It has nothing to do about what "makes you feel better", but it has all to do with helping my engine run cooler, period. If you don't believe my numbers show these mods can work, then show this forum your actual real world research and numbers that show these mods DON'T work. Many RX8club members have used, and have recommended one or more of these mods, and they have reported that it helped then (search ALL the cooling threads posts if you don't believe this !). You can choose not to believe those other members either,so be it.

What is your proof that the rest of us know nothing, including known longtime Mazda experts such as Racing Beat, Pettit Racing, Rotary Performance, Mazsport, JPR Imports, and top vendors including Mazmart, and even a couple of your fellow RX8club moderators. These folks have done their own vast experience and real-world solutions to help rotary engine cooling, used one or more of these or similar mods and have even recommended them to fellow members. Unless we all know nothing and have no real-world experience in these matters,, and you folks know everything about all cooling mods, then some of your more dismissive arguments carry less weight.

Hey everyone on this forum has a certain knowledge to impart or a desire to learn. I am on this forum to learn as well as to share knowledge. No one member knows everything about all issues. But to dismiss, out of hand, so many with real-world experience, that is a disservice to the newer members, who aren't tuned into this forum's often nasty politics of personal dislikes, that sometimes clouds certain members' reactions to posts and points of view of certain other members, no matter the validity.

NotAPreppie

You haven't even read most of what I wrote, have you? My best guess is that you saw my username, saw that disagreed with you, saw the constructive critique and decided to be offended.

Interestingly, even after you said you were done, you came back for more. I'm not really certain what to make of that.

That said, you if you follow the logic train you can easily see how a thermostat opening at a lower temperature won't do much without fan activation at a lower temperature. But 180°F is a perfectly acceptable temperature, so why lower it even further? It's wasted money unless you first upgrade at least the fans (if not the radiator as well).

Similarly, upgrading the radiator without changing the fan trigger temps won't do anything if you're not moving. Radiators require airflow to work. If your fans don't turn on until 207°F, Yahweh's Blessed Radiator won't keep your temperatures under that.

Others have noted that additional oil cooling didn't help them much even when boosted.
https://www.rx8club.com/rx-8-discuss...2/#post4714650

If you want to do some reading, I encourage you to read this post:
https://www.rx8club.com/rx-8-racing-...k-cars-262908/


First, let me just critique your argument in this paragraph.
You've provided good examples of two common logical fallacies:
"Argument from Authority"
Just because somebody is a moderator or experience product engineers doesn't mean that they are infallibly correct all the time. Additionally,

"Strawman"
Ideally, all products will solve problems. These products certainly do that and nobody is arguing that they don't do what they advertise. Nobody is arguing that the developers of these products aren't qualified. My argument is that they have to be used correctly.

The issue I have is in your proscribed application of them. In your scenario, only one of the three things you did would have made any real difference.

Additionally, I don't really care what you do to your car. But the point of this post wasn't "Here's what I did, isn't this neat?" Had it been that type of post, I would have kept scrolling. Instead, you titled, formatted and presented your information as an informative post to "help" newer owners. Unfortunately, 2/3rds of what you wrote would be a disservice to the overwhelming majority of this community.

This last paragraph is a textbook case of "the pot calling the kettle black."

I don't know if I agree with your the statement that I bolded. You tend to take positions and when people try to politely show you how your positions aren't supported by the evidence, you immediately go on the defensive as though you were personally insulted (granted, 9krpmrx8 can be pretty insulting but you've behaved this way with me in other threads). A person who is here to learn would take logical arguments seriously, even if they end up rejecting them. To date, I don't think I've ever seen you deconstruct an argument point-by-point to show why you think it is incorrect. Nor have I seen you actually accept another person's argument after they've laid it out for you.

This is part of the reason why 9krpmrx8 behaves like a tool in your posts (though partly I think he's just an abrasive type of person). This doesn't excuse his behavior but it does explain it. From what I've seen, you fall into the trap of motivated reasoning and confirmation bias quite often. Your condescension while doing this just makes it even more silly.

If you would like to read my posts and give me a point-by-point critique about why you think I'm wrong, I'm open to the discussion. So far all you have done is present a number of textbook logical fallacies.

NotAPreppie

This is true in the absolute sense but the effect is pretty limited in the real world. To put it another way, if you're relying on humidity to keep you out of the danger zone you're going to have a bad time.

Air has a specific heat of about 1kJ/kgK at room temp.
Water vapor has a heat capacity of roughly double that.

At 60% relative humidity at 20°C there's about 10g of water for every 1 kg of air so that's about a 2% difference. Not only that, but we're talking about an INCREASE in specific heat: that means the more humid it is, the more heat the air can absorb per degree of temperature increase. So, it's actually a theorectical 2% IMPROVEMENT in cooling performance.

Drier air is actually worse for cooling convective and radiative systems. Even though there's much less water in the air during the winter, the loss in cooling performance is more than made up for by the greater differential in temperature.

gwilliams6

Notapreppie the fan relay kit does trigger at an earlier temp. Guess you have never seen one in action or read up on that one. You certainly like to write ,even more than I, but nothing you have said or posted really shoots down the reality that some of these cooling mods can work to lower temps down to safer territory for your engine. And nothing you have posted will change those who have seen cooling improvements using different mods that you think don't work.

NotAPreppie

Man, your reading comprehension skills are amazing.

I addressed that. Read what I wrote and try again.

dannobre

iTrader: (3)

Not sure why you 2 are still at this. You have a difference of opinion. ..get over it and move on

You both have your points. .. and your tentorium shoved up your bases....

Let it go

pistonhater

Jeez, yea, lots of drama.

Ok, so it seems the only cooling mod that makes a difference is triggering the fans to run earlier than the factory settings.

But the other mods are not much money. 75 bux for a thermostat? What's the big deal? It's people's money spent on their cars. Let it be.

NotAPreppie

{juvenile denial voice}He was the one that kept coming back for more even after he said he was done!{/juvenile denial voice}

nycgps

iTrader: (1)

before I start working/fixing rotary/automobiles for a living, I would jump into these *discussions*

after working in it (yeah, started my own shop), well, no more

cuz what I've learned (in business) is that don't try to change someone's mind, no matter how much u tell them, once they believed in something, whatever it is, it will never changed, period.

I mean, just do whatever u feel comfortable with, it's ur car, hell u can pour gas on it and light it up if u want to, jeeze.

Nisaja

Guys guys! Chill out. Let's not fight. We are a happy family lol.

I've done a fair amount of research on cooling because I'm suffering from a mild overheating issue, so here's my take on this.

I just read through the whole thread, and, some of you guys think a functioning cooling system is perfectly enough to keep the car cool in hot weather. My car is a 2012 JDM model with around 3500 miles now, bone stock, and although it doesn't really OVERHEAT, it runs pretty hot. It'll hit 220F in 95F weather. And it only happens when I'm stuck in traffic or idling. When cruising down the highway at 60mph, the temps will drop to 197F and stay there. And I'm not the only one here. Plenty of RX-8s where I live have the same problem. My buddy's R3 hits 226F when idling in 98F weather. If you guys do enough research, you guys will come across threads from 2004 about the fans staying on after shutting off the car for minutes. Now they stay on for 5 seconds when the coolant temp is above 213F, but they stay on for MINUTES when the coolant temp is above 230F! So that means even brand new cars had overheating issues. Maybe they didn't overheat, but they certainly ran pretty hot.

One member pointed out that since my car is an automatic, it has to deal with the heat coming off the AT cooler. That could be why it's slightly hotter, but still, a car with a "perfectly functioning" cooling system will still run hot in hot weather.

I must admit I haven't done a lot of mods to solve this. But I can tell that if a car is overheating, a lower temp thermostat isn't gonna help. Think about it. What's the point of the thermostat opening at 170F if the car can't maintain that temp? If the fans can cool the temps down to 170F, it's all good. But otherwise it's pointless. It'll only DELAY the overheating.

Now a lotta people overheat while idling in traffic. Some say turning on the fans at a lower temp will help. I don't get the logic behind that. When I'm stuck in traffic, I have the AC on full. The AC on full forces the fans to spin at full speed. My fans turn on with the AC the second I start it, even if the coolant temp is 120F. So all the time I'm crawling slowly in traffic/idling, the fans are running on full speed. One could argue that it'll help when the car is moving. If the coolant temp is over 206, the fans will be on low speed, even while moving. At 213F it'll switch to high speed and, again, stay on while moving.

I think the only two things you can do to keep your car cooler, is to get a bigger radiator and faster fans. Bigger radiator holds more coolant. Faster fans move more air through it, absorbing more heat. I'd love to get faster fans, but I'm too broke lol

The only mod I've done, is seal around the radiator. Now this really helps. It'll force more air to go through the radiator at speed, and when idling in traffic, stop hot air from the engine bay creeping around the edges of the radiator and getting sucked back in through the radiator. If anyone is running hot, I think this is the first thing you should do. A lotta guys have hanging/broken under trays that send the air that's supposed to hit the radiator right below the car lol. The stock foam that comes from the factory gets brittle with time and falls off too.

In my opinion, this is the number 1 DIY mod for lowering coolant temps. It really works and it has lowered my temps by at least 5 degrees. Can't go wrong.

nycgps

iTrader: (1)

this is actually normal in Mazda's term.

there are cars out there with a higher acceptable "limit"

you can lower it slightly if you uses more H2O than Anti-freeze, and ur fan must be functional, just because it moves it does NOT mean it's functional.

it's also normal, once ur engine stops, coolant stops moving, but heat is still inside and some spot will heat up instantly, this is why they designed the fan to turn on.

if you guys think rx8 runs hot, try a RX7 FD3S, parts of the cooling system boils INSTANTLY the moment u shut it off.

engine generate more heat than the tranny.

170f is too cool.


turning on AC will ALWAYS turn the cooling fan on, its by design, and that's just 1 of the few stuff that "triggers" the fan.

you also might want to check and see if your radiator is clogged in any way, just use a infrared temp sensor to check, stock rad gets clogged up. replace it with a quality piece, OEM or good quality one (read: NOT CHEAP ****)

I fixed too many rx8 to know that now.

Nisaja

Yeah I know that Mazda thinks it's normal, but this club thinks otherwise. If it's normal, why are we talking over here about how to reduce coolant temps?

I tried a 30/70 coolant blend. 30% coolant and 70% water. Didn't make a difference the fans are literally new.

Yeah I know the fans are designed to run when the engine turns off, but that happens when the coolant temp is over 230F at shutoff. 230F is pretty hot. And this happened to new cars back in 2004. That means new RX-8s with perfectly functioning coolant systems went over 220F.

Good idea. That way I can check if the radiator is blocked. I'll have to get an infrared temp sensor for that.

NotAPreppie

Given the location of the AC condenser, operating the AC will increase temperatures.

I've also noticed that my fans don't spin on high all the time when the AC is running. At least one of them cycles on and off.

Nisaja

They cycle on and off, but they stay on constantly in very hot weather when the AC is on full.

NotAPreppie

Yah, if you're already running hot enough for the fans to run high speed, adding the head from the AC condenser will only make it worse.

kevinande

You could slow down. Less load equals less heat. You could possibly enjoy your air by driving slower than the posted limit.

Nisaja

But even when the coolant is like 190F, turning the AC on will still keep the fans on full speed. I think it depends on the AC setting. I keep mine mostly on max (coz its hot AF over here ). Yeah whenever it hits 220F, I turn the AC off and it drops right back to 206F, until fans go into low speed.

Sealing around the radiator have helped a lot. Now I don't see 220F often. Only when it's really hot outside. It normally stops around 215F now. Everyone should try this. It really helps. People don't think how some foam can make a difference but try it first. It's cheap.

Jastreb

iTrader: (1)

Yes but what has all the extra foam done to your under-hood temperatures? How much foam was there from the factory? I recently installed an Koyo HH-series radiator, and I added foam to the sides of the radiator where previously there was none. I am now seeing 5 deg F higher intake air temperatures on average when moving, and when stuck in traffic the heat soak seems more rapid, with intake air temperatures higher than I had seen before. After half an hour in traffic, not moving, in 100F heat, I was looking at the following situation: A/C off, fans on, intake air temperature of 170F, coolant temperature of 190F. The intake temperature had climbed until it stabilized at 170F, and at that point the fans stayed on constantly irrespective of coolant temps dropping below the fan activiation set-point. Incidentally, it looks like my ageing battery kicked the bucket recently, and I wonder if it had to do with the extreme heat soak.

Now, I could have something weird going on, like only 1 fan working and 1 not working, but barring that, I plan on removing some foam from the passenger side of the radiator.