After a week of getting my car to settle in after installing Scott’s fan mod, I decided to do some real testing with my canscan of the coolant temps.

Some initial info: I ran all the tests with all the accessories (A/C, Radio, lights), I’m running royal purple 5W-30 and royal purple premix. The temps varied between 88degrees for the first test to 83degrees with the cooling mod out. I also have redline water wetter in the car. With a 50%/50% eth/water mix.

Per the service manual, Mazda says the initial operating temp should be 176-183 and full operating temp is 203. I’m not sure if that means 203 is the hottest temp you should ever see or that’s just how hot you can expect the coolant to get under hard driving.

Tests with Fan Modification:

First test – 5 minute idle with mod – After warming the car up, I let the car sit and idle for 5 minutes in my garage while it was 88degrees outside. Zero airflow, the temps never exceeded 183.

Second Test – Hwy Driving @ 70mph – I drove over to RG’s house which is a good 25mi away, cruising at 70mph on cruise, the coolant temps never exceeded 186.

Third Test – Hard Driving under heavy load – RG and I found a open road, ran the car up to redline several times backing off there after. The temps jumped to 194-196. We then proceeded to drive in 2nd and 3rd gear under heavy load at 50-60mph, 6000-8000 rpm, we got the temps to 199-203. 203 was as hot as we could get the temps, and we were doing things you would never do, because normally on the track, when I’m holding 7000 – 8000rpm, I’m doing 70-90mph, with some serious airflow.

Fourth Test – Stop and go traffic @95+ temps – TBD, I need it to heat up here enough to test the mod under more brutal conditions, stay tuned. This test will likely show the real worth of the mod, as I know what happens to RX7's that aren't cooled properly in the same conditions.

Tests with the Fan Modification Disabled:

First test – 5 minute idle with mod – After warming the car up, I let the car sit and idle for 5 minutes outside while it was 82degrees outside. Zero airflow, the temps fluctuated between 183-185, fans were clicking on an off.

Second Test – Hwy Driving @ 70mph – I drove home from RG’s house, the coolant temps were between 190-192, I did see it drop to 188 once. Temps outside were 82degrees.

I didn’t do a hard driving test without the mod, frankly after seeing the results, I didn’t want to, I like the safety net I get with the mod. I wonder how hot my temps were at the track last time I really drove the car hard.

Conclusion:

combined with a 5W-30 weight oil, this is a great mod to keep the cars operating temps in check, which keep oil temps down as well. Is it worth $150? Most definately. I really want to see my temps in hot Houston traffic, where I think it will really show its worth.

 

too me it makes alot of sense, why are people debating and investing so much money into a "cold air intake" when you can simply lower the whole temperature of the engine. I know that the 2 mods are relatively unrelatable, but I know that I feel a difference specifically in the A/C, and for 150 bucks I think it's worth it

 

I think I will have to look into this... even though I know our engines run hotter then usual even after a short drive for errands my car felt "tired" and even after a bit of cooling off anything in the engine bay was too hot to touch


drop us a link as to where you got your stuff Brillo

 

http://www.mazsport.net/store/page9.html

 

Besides just the hotter areas of the US, i think this is a great upgrade for rx8 owners who endure hours upon hours of traffic through out the year (which seems to be a achilles heel of the rotary, high heat+no movement.) I will be definitely close to buying this in the early months of next spring after going through a couple months of traffic in 100+ heat this past summer.

Also brillo i found a picture of RG's house:

If anyones 8 is dealing with major heat its you two.

 

I just want to elaborate on how hard we were to the car to get the temps up. Brillo sat in the passenger seat watching the Canscan while I drove his car. Brave guy! The best thing I could think of was to go as slow as possible to keep airflow as slow as possible (as opposed to higher gears) while still staying at the highest rpms and loads possible. That means full throttle runs in 2nd gear and runs to and holding at 8500 rpm!!! We found a back country road that was fairly quiet. Staying in second gear makes it hard to go obscenely fast which is good for legality reasons. We pretty much were limited to about 65 mph but did hit it many times. Remember this was only in 2nd gear. I would wind the car up and then let it decelerate down in gear several times. This was very hard on the engine and for a while we just cruised around at 6000 rpm. On a track rpm's would fluctuate more and speeds would be higher which means more cooling airflow would be available. The outside temps were in the upper 80's. I'd be curious to see how it would have done in the heat of the day (upper 90's) in direct sunlight but for the most part abusing it as hard as I could would only manage to get the temp up to 203F. We saw temps after hard driving with Scott's mod that we managed to hit with the stock setup and easy driving. That's pretty convincing. 3rd gen RX-7's could hit 220+F temps sitting still in Houston traffic. The RX-8 with Scott's mod would hover at about 183F and I couldn't hit over 203 abusing the hell out of it. I still think that if I tried hard enough in the heat of the day that I could get it to 210F but we'll probably never know. That's pretty nice. I wouldn't want to treat many piston engines as hard as I did the rotary yesterday.

 

Good info. Curious what the oil temps were? I run about the same set up--RP 10W/30 I run a 60/40 coolant, no red line, i do have an agency power pulley on so a little undrive is present. no a/c--oil cooler screens(they do block a little flow)
I have only gotten my coolant temps up to 210F once and that was mid session at Roebling Road in Savannah Ga--track ambient temp was 100F. Oil temp was 230F. Highest oil temp seen was a red flag stop at Road Atlanta and temp was already 225--i turned the a/c on and the fans was cooling the coolant but the oil temp hit 240 and kept climbing--i shut her down.
good stuff.
olddragger

 

i will add that yesterday... outside temp 97 to 98 stop and go driving and highway cruising. and on or two redlines. temp never broke 190... this was a 100 mile drive.

but i did not do the run the **** out of the car during this test...

beers

 

You guys could drive over here and do some testing. It has been 114 the last two days driving home in stop and go traffic. With the A/C fan on 3. Gets to cold inside on 4. lol
All in all it sounds like the kit works.

 

Every rotor needs real gauges
OD

 

I second that. I would be a lot more comfortable (or uncomfortable?) with real gauges.

These idiot gauges **** me off. I am going to have to spend money to get oil and water temps and oil pressure.

It's not a real sports car unless it has gauges.

Yeah, I know, what's my excuse for buying this car then?

Um, it was the closest I could find (Caymans are looking better and better).

I need to seriously look at getting the fans to run more, however I do it.

 

i noticed something of interest today. Coming back from the south east's biggest soccer tournament(13000 players) on I 75 it was 95F. Clear weather and traffic was heavy. We where crusing at about 70, i was in heavy traffic but mantaining a distance of about 3 car lenghts from any other s. I looked and dang oil temp was at 200F and coolant temp was 200F! It usually doesnt ever do that unless I am doing a lot of passing or "Playing". A few miles on down the road the traffic thinned and my temps came down to 185-190 coolant and 190 oiltemps(the usual.) Was I getting some kind of draft affect? I dont know--it was just an observation I thought i would share.
olddragge

 

so many pages on this new part and nobody has posted a pic of one installed yet ....

 

There's not too much to see but a pictures are on the Mazsport website.

 

I didn't see any "installed" pics, just the device it self

 

this what you are looking for???

http://www.mazsport.net/store/instal...fancontrol.htm

beers

 

The device, where the ground attaches to & the two relays that have a wire that goes to the device.

 

I'm curious, if all this does is change the fan turn-on temps, and these modified set points are universally better in all cases...why didn't Mazda do it that way? Is it less ideal for cold weather operation or something?

How do the new turn-on temps compare with the new temps used in the Racing Beat PCM reflash, anyone know? I guess if one were getting that reflash, this device would be unnecessary, right?

jds

 

Emissions. Hotter temps = better emmisions

My understanding is that the RB reflash does something very similar to this Mod, but this mod is permanent and will not be lost due to any future factory reflashes like to RB flash will.

 

non of the emmisions temp have changed since i have installed mine...

beers

 

I don't understand - what are you referring to as an "emmisions temp"?

 

Just as a balance point on this:

I have my fans wired to a switch that keeps them both on full. My results almost exatly mirror Brillo's, except my ambient is about 110°F
My peak temps almost never excede 197°F unless I can alternate between full boosted runs and sitting in stop and go.
It took a medium altitude mountain climb in near constant boost and 117°F ambient for over 1/2 hour to get my coolant temps over the limit.

 

cat temp.... is with in 5 deg off what it was before the mod...

beers

 

mm,

would love to be along for that ride....

also... tracking # for you late late tonight.

beers

 

I think what they are getting at with regards to "emissions temp" is the nominal coolant temperature for best emissions.
Generally, though it is better for power, an engine that runs cooler, runs dirtier.
203°F coolant temps would probably yield the cleanest exhaust.

The CAT temp wanders back and forth depending on load. It can be anywhere from 1100°F to 2000°F and still be in nominal operating range (with different life expectancies, of course).