Most stock 8's in our summer weather conditions should stabilize at around 185F at cruise. I would like to see proof of an RX-8 cruising at 172F on 90+F weather. If the weather is cool yes, but not in the heat of the day during the summer. No way.

at highway cruise 90+ my temps are slightly below 180. mizu rad and hoses, mazmart wp and t stat

I don't think that it devalues the Mazmart thermostat. Just that with your thermostat fully open and temps still not dropping it means your radiator needs to improve it's ability to shed heat. If your radiator can't get the temp down to the thermostat open temperature, they yeah, lowering the thermostat won't produce a visible effect.


That doesn't mean that they "don't work".

What are you using to monitor coolant temps? OBD port?

prosport gauges and ap. my water temp sensor is where the pipe used to be between rad hose and block hose

Not sure if ambient temp is logged, but would a log of intake temp plus the other normal points suffice?

I'll get one next time it tops 90F here. It's been hovering high 80s pretty much non-stop so won't take much to get to the 90F you ask for.

Granted, I have the coolant issue, but I don't think that would impact this?



Another possibility is the humidity? Higher water content in the air could mean better heat shedding from the radiator. You have drier air than I do.

I'm using the OBDII port, I'll get readings on my way back through the VA mountains when its 63* outside :(.

See what my temps are at...

I don't have an issue, my temps are quite low considering the addition of the turbo and the intense heat we experience here in South Texas and I attribute that only to my more efficient fans and secondary rad. I'm just saying that before, when I installed the Mazmart pump and thermostat I saw no difference in coolant temps what so ever. I just don't think it's worth the money if your OEM coolant system is working as it should. I think people buy those items thinking it will lower coolant temps and from what I have seen that is just not the case.

It may help with cavitation, etc. but i'm not sure how you would know if that were the case.

People also say the under tray plays a very important role in cooling yet a few guys locally have run without it for some time under the same conditions and never see any higher temps than anyone else.

To counter that, I have personally seen several examples where better sealing of the undertray HAS dropped coolant temps.


If you can show examples where they don't work, then both sets are viable possibilities. There are just more factors / variables influencing the end result that aren't being considered.

What is the difference between the two usually? I know from testing that taking a reading from the heater hose usually varies as much as 10F from what the factory coolant sensor is seeing.

Intake temps at cruise are usually a non issue unless you are running a hot air intake or something. AMB is not logged. I dunno, humidity supposedly helps but it's pretty damn humid here :lol: it's not really dry at all.

Referencing intake temp as an indirect method of getting to ambient to show them both in a log.

I dont have an undertray and see the same temps everyone else does...

Just saying.

Thanks for clearing that up RIWWP, I'll add the thermostat to the list.

I do a lot of city driving so I don't think it would be worth getting the pump too.

I think my OEM thermostat was headed toward failure (104,000 miles), and would expect that a brand new OEM thermostat would have the correct 183F to 203F range.

That's fine, 203 is too hot for my Kool-Aid anyway. :)

9k, temps are usually pretty close between gauge and ap. oil temp is usually a couple deg cooler. i did open up the splash shields behind oil coolers too

Intake temps are a funny thing, I find they vary even on stock setups. But like you said, there are so many variables.

the mazmart pump will cavitate much less at higher rpm-the oem water pump will start cavitation at 6K.
Look at the design of the S2 water pump, look at what the track guys do. Now--yes --different operating conditions, different average rpm usage by the racing guys, but the impeller on the MM pump will still pump well in the lower rpms. Is it a must before you can have a good operating cooling system---no. but it is a good thing to have if you do canyon runs, track days etc.
In Ga , during cruise on the interstate, ambient temps less than 95F, with the a/c on--i will see approx 175-178F ect, oil is about 15-20F higher.
9 k those are good temps considering that you have that intercooler up front.

Yeah, remember though they upgraded the impeller on the S1 pump as well so if you have a reman you have the updated pump. I am really happy considering I have the inter-cooler up front and my second oil cooler up against the condenser as well. My system is forever changing, I will be going to dual oil coolers in the stock locations soon and so I will have to mount my secondary rad differently as well. My oil temps actually stay a bit under what water temps are unless I am really driving hard.

Thread revive. Going to be a Mizu owner right about now! my radiator top hat broke. So i'm ordering a new Radiator, Radiator Hoses and rest of the other hoses oem. here's some pics for you guys. :mdrmed:

Attachment 230314

Attachment 230315

Attachment 230316

Attachment 230317

Texas weather killed my radiator but oh well new bling and cause


Attachment 230318

How are the fans holding up? No more procrastinating for me, Fan #1 just took a dump, just in time for summer. :(

Looking at this one...

Flex A Lite 12 1 8" Dual Shrouded Pusher or Puller Universal Electric Fan | eBay

The fans are a larger factor in actual cooling then the after market rads.

That being said man that nipple is a B and I cant blame you for replacing it at all. Lets us all know how it turns out.

I'm thinking about running two of these... Amp draw of 7, CFM at 1150, full setup would be 14 amps, 2300 CFM's.


AFCO 80180 Electric Cooling Fan, 12 Inch S-Blade - Speedway Motors, America's Oldest Speed Shop

Are Yall capable of replacing the fans without removing the radiator? I only ask because my upper neck has a crack where the hose slides over it and I doubt it will survive me removing that hose again. Normally I would just go ahead a replace both but I'm being a penny pincher right now cause I'm trying to save up to get a house.

Shady, any reason why you prefer a fan set up without a shroud? From my understanding a shroud helps for low speed cooling which is what I need. Majority of my driving is city traffic.

I would get a custom shroud made...

Our alternator can barely supply the amperage needed as it is with factory equipment. People go and add more electronics, sound systems, etc and it stresses the system out even more.

Reducing that amperage while keeping CFM's the same would be an ideal situation that is essentially what those fans would do.

You can use my Mizu shroud, it is just sitting there. I have the upgraded FAL fans and a secondary radiator fan and my electronics are just fine. Now if you go adding crazy stereo shit then yeah for sure.

I think it's more how it gets wired up. Think about people like Dannobre who have a diff cooler pump, trans cooler pump, electric water pump, etc., etc. and have no issues. Those pumps draw a lot more amps than fans do.

Amp draw is amp draw...

The less you have the better.

I wont be able to afford those fans for another year or so though LOL.

Yeah but if the added amp draw is a non issue then it's a non issue. We shall see on Hoss's car, he has the larger Fal's and will have two other fans as well. But if the pumps the race guys are running don't cause an issue then I doubt he will have a problem.

I'm confused now... Doesn't our cars have a 40amp fuse for the fans to begin with?
How would a 30amp draw stress the system?
The only "extra" current I'm pulling is 5v 2amp for my tablet. Everything else is stock. No intentions of ever adding a sound system... I much rather listen to the engine most days anyway.

The more current the system draws the harder the alternator works, the harder it works the more energy is required to spin it.

The more energy required = less HP and less MPG.

The alternator is capable of handling that just fine, that's not the issue. the more amps you draw at idle the more your alt will need to create causing your engine to work slightly harder, which will cause your idle temps to rise.

See where I am getting at :).

I don't think that is how it works, the regulator adjusts to compensate for the engine speed and voltage needed at any given time, etc. Other than at idle, the engine speed doesn't need to increase to supply sufficient voltage during normal engine operation. Meaning if you are cruising at 3,000 rpms and you turn everything on, the RPMS or load will not increase.

There's a reason Jeff has you turn everything on when you are doing the cruise logs ;).

Give this a read if you are curious.

http://www.delcoremy.com/documents/h...ite-paper.aspx

Basically the alternator is turning fuel into energy, the more energy you need the more fuel you need.

Think of it like a house, if you turn on all your lights and AC you are using more watts/amps. the more you use the more the utility needs to feed you, the more houses their are the larger the power plant needs to be.

Same thing with a car, the power plant is the alternator, and everything that needs power is a house.

Right, did you actually read that? That is about efficiency. But that is not what you are implying. You are implying that as voltage is needed to power certain items, the alternator has to work harder, thus taking more energy from the engine to supply that voltage. That is simply not true.

At 3,000 rpm a typical alternator can supply more than enough (too much actually) voltage than is ever needed so the regulator controls what is needed. When that extra voltage is needed the alternator does not require more fuel or physical energy from the engine to supply the extra voltage, it already has the ability to provide more than enough voltage.

And my 3,000RPM example is just a number pulled out of my head, from what I have read most alternators reach max output just off idle.

Mizu radiator on back order on sparkplugs.com.... Just my luck.

Shady I KNOW you didnt read that....slacker!

Having all the electronics on increases load to the alternator. Theres an efficiency range for our alternators I am guessing somewhere around 4500 or 5000 rpm it reaches a break even point where it starts generating excess amperage. There hasn't been enough testing done to verify this but I am super interested in finding out :)

Anyways as your engine speed increases the alternator output increases its a sliding scale so at 5000 rpm the output is greater than at 3500 rpm.

Anyways back to the fans, they will only be on at idle, less draw at idle, less output needed from the alternator, this keeps the car running cooler and gas consumption lower...

I read the last part of it... LOL

we just dont have enough data from our alternator to prove anything. A test will be needed!

I just need a higher AMP rated Fluke

I dont get how a fan with 5 less amps (45%) can pull 3000cfm (almost 20%) if it was that easy I think FAL would have done it ;)

The best test would be to get on a dyno set cruise cotnrol at 3800 log for 30 seconds, then turn on the headlights, stereo, etc for 30 seconds.

If the calculate load does not increase then I am wrong.

You are wrong my friend. Stubborn and wrong, :lol: Just do some reading, most alternators reach max output at just off idle even with a full load on them. So you can increase engine speed all you want the alternator is not causing the engine to work any harder.

If I am cruising at 3,000RPM's on a flat road and I switch all my fans on, turn on the AC, turn on the radio, etc. I will see no more engine load than I already was seeing. And even if it blipped a little with the electrical load coming on all at once, the voltage regulator in the alternator would adjust and work it all out in a second.

It would take a shit load of stuff running all at the same time to get to a point where our alternator would be overloaded.

I know you won't read it but this is a good discussion about it.

http://www.physicsforums.com/showthread.php?t=481577

It doesnt, the fan pulls 7.7 amps at 1125 CFM.

Two fans would be 15.4 amps at 2250 total CFM.

yea, I was ready the max output...nm

but 9k is right man...if the alternator didn't do its job right off the bat all kinds of shit would happen....fans are cool though ;)

There are zero downsides to running a larger fan set up. The only problem i can see is the draw being to much for the stock harness.

The stock wires are plenty big enough for higher draw fans.....if you are worried about it just wire in bigger wire from the relay to the fan and be done with it :)

You should have posted a picture of your huge fan(s) in your post, :lol:

LOL...I will start a thread about the swap I guess...had it at the track yesterday.....damn it goes like stink :)

Do it, I am dying to see how it turned out.

His 16" fan pulls 10 amps...

I am beating this thing till its dead.