Okay guys, we had our statewide meet this past weekend and typically I get hotter temps up in the canyons due to the longer running time compared to the track and autox. Although I have not been on the track or autox with my current setup.

The car ran okay this weekend but I am still trying to improve things. I currently have a motor with 12k on it, new koyo radiator, new hoses, and new coolant. I am running a single Fluidyne oil cooler with a perma cool oil thermostat.

The problem is that I am seeing coolant temps in the 220-230F range when pushing the car hard in 80-90F weather. My oil temps are not getting any higher than 220F and when I hit a straight the oil temps drop immediately 20-30 degrees. I tried running 90% distilled water and 10% straight coolant and it did not reduce temps so I changed to 100% 50/50 coolant and a bottle of water wetter and still no real difference in temps at the limit. I properly burped the system and drained the block.

There were some others on the run seeing water temps in that range at times. On days like today (90F) can see coolant temps of 200F in normal driving which is higher than I normally say when I was running the OEM radiator.

I know, I should have not been a cheap *** and went with the Griffin or the Ron Davis. Lesson learned.

Anyway, can you guys tell me what your highest temps are at the limit? Thanks.

 

I've seen 236°F but that was on a canyon run out in Vegas in 115°F weather. (when we suddenly came to a screaching halt and the cars weren't getting any air)

I'm going for a drive in the canyons this weekend so I'll report back what my temps are.


P.S. have you thought about the mazmart water pump?

 

Thanks man, I appreciate it. I am thinking about the pump and thermo but I read here that my new engine should have the updated water pump. I'm also thinking of just ditching the Koyo all together but that will have to wait until after vegas

 

Mazdamaniacs experience and a few others around AZ have shown that the KOYO can have worse cooling that the stock radiator in the summer time. On and off the track.
And if your opil cooler is in front of the rad,, well,, that doesn't help either. Oh and you might try a 35-40% Antifreeze and 65-60% water with a bottle of water wetter.

 

Yeah I am thinking the Koyo is the problem. My oil cooler is blocking a bit but with the OEM cooler it was not a problem. I am also thinking of adding a smaller extra cooler in the OEM oil cooler spot. I just wanna see if my temps are way out of range.

 

I'm afraid I have had the same problem with the Koyo....can't really figure out why....but for a track rad it sucks...


I bought a Ron Davis Racing Rad...now that thing is massive

 

9krpm,
You know my 07 auto 8 has all original parts down to the plugs, and fuel pump. When I ran H2R May 09, the outside temp got up to 93deg, and my water was showing 229deg. That's the highest temp I'm comfortable with, but it WAS ***** to the wall gas or brakes for 20 minutes while I got 8mpg. Your 220-230deg doesn't sound bad in comparison since you're also climbing some elevation, and my car didn't get over 7k. I heard OD suggest keeping revs below 8k which considering your name might seem tricky to do.
However, I have an idea. Since you've already spent all the effort on your radiator mods, why don't you rig some electric fans under your hood. I fan on each cowling inside the engine bay pushing air out the black fender strakes area. Also, maybe behind each oil cooler, but you get the idea.
A FLIR camera could help; I'd like to see some tests with imaging to see what really works. Your cruising 200deg sounds OK so I don't think you're that far off.

 

water temp for 220 - 230, ins't it regular? i think the stock car, if i remember, the fan start kicking in when it reaches 220 - 225 , something like that...and at that time, the temp water will be lower, to 200 degree...
oil temp, it's usually around 200 and more...and of course when you are cruising, it will get cooler....
i have turbo for more than 20k miles, and i have all the gauges...
i have: KOYO radiator, Mazmart water pump, and upgraded fan (mazsport).
what i notice is when it's hot outside around 95 F, i have water temp is around 185 degree, constantly cruising or with the turbo spooling, sometimes 190 F when i keep boosting it......but my fan is always working.....it's goes up of course when you stop and it will go down when the fan works....
oil temp, i need to get the duct, because when i boost, it goes to 230 F...LOL...
i hope my information helps you..
steven

 

Went to DGRRX a few weeks ago and after a few runs on the Tail of the Dragon, my oil temp peaked at 220F and my water temp peaked at just under 220F. Temp outside was ~80F.

 

Thanks guys, good input. REDRX3RX8, thanks for the idea, I actually have access to a FLIR camera, I will have to borrow it

I am thinking of creating some duct work from the factory oil cooler location to my radiator. I am also thinking of fans too. Or possibly a second radiator with a fan that I can switch on and off manually.

 

Ron Davis and Griffin are great radiators. I used them exclusively and are the top choice for those in all Sprint Car racing series

It hit 90 degrees last weekend in the NE and stuck in traffic not moving my temps climbed to 230 on the water and 210 on the oil. Once moving in that weather though there was no issue; water went back down to 180 on the highway and oil 160. If I'm not on a highway it's usually 200 for water and 180 for oil. I did the oil mod to add slits on the back of the oil cooler in Ash's DIY mod to help some cooling as well.

I wouldn't worry about water as much as I would oil; the water is just for cooling the oil while the oil obviously is the main cooling portion we should be concerned on for the engine. I believe all my past vehicles were up at 200-230F for water. Hell when I raced with motorcycle engines back in the day we were at 220-230F for water consistently with how much we were revving those engines hitting the rev limiter constantly.

 

9K--- 230F from what I understand is too high. I believe it was a racing team a couple years ago that identified that the plates will start to get misshapened at that temp and even though you will not see an immediate problem you will affect the life of the engine.
Someone please correct me if I am wrong.
I would never let my engine get over 220F coolant.
I am not concerned about oil temps as long as they stay under 260F or so
1st thing I would do is get rid of that radiator---lesson learned. heard many people had this obs with that Rad
You have a perfect setup for a small additional coolant radiator in the old oil cooler position. It can be ran off the heater hoses. A small fan if you want is available for that area.
It doesnt take a big secondary radiator to help. Our car has such a restriction of air flow through the radiator thats its efficency can never be fully utilized.
For example
Track session in 92F day humidity approx 40%
coolant temps never over 190F
sitting in traffic on a high 80F day coolant temps never over 195. My fans turn on at 180F
OD

 

Yeah, I may go the second radiator route and OD, I agree on the flow part because my oil cooler cools oil very quick at speed and my water temp is slower to cool and I believe its is due to the lack of flow. My oil cooler get good flow if I am moving at any decent speed.

I don't like the high temps, at the end of the day my car was heat soaked and idling rough. I might order up a second radiator today.

 

Hi 9K....

Going off Mazda's specs but the Original Thermostat Opens at 176-183 F and FULLY open at 203F.

S2's Cooling Fans are set (according to specs) High Fan above 226F, Medium 214-226F, Low 207-213., so the Fan in an S2 does not come on (low) until 207 F.

I would be trying to get my fans on earlier 9K...may help???

 

I wonder if I should just remove the thermostat all together. I will probably be getting the AP soon. Just not looking forward to buying something and then waiting months to be able to make use of it.

 

the duct is good, are you talking about fans for radiator or oil cooler? i don't think you can add more fan for radiator......but i don't know,maybe someone has 3 of them instead of 2...:LOL:
but fan for oil cooler, i think Race Root has sold them lately, and it's preety good, or you can upgrade it to bigger one...
my friend used to have a kit from RE Amemiya which override the fan system...
you can turn off and turn on, by using the external switch....check it out..you can turn it on earlier adn keep it on...

OD, when the car is stock, do you know when the fan start kicking in? because i think it's around 220...right? i forgot....LOL....i beleive at that number,,,
about the oil temp, i agree with it, as long as it's not over 260..because oil is always hot....especially when it's driven alot...
my water temp never pass 195 either...

tha'ts the best thing because you can turn on the fan earlier...

 

I have a single 28" Fluidyne oil cooler and deleted the two factory coolers.



So I am thinking of one of these in the factory oil cooler location, possibly even a dual cooler

 

Interesting, I was thinking about cooling systems as well since summer is here in Florida. Days having been reaching around 85-92 degrees all ready. My cruising speed on highway temps are, 186 water and about 190 for oil. Now in town with traffic and some high RPM's i have seen my water temp go to 204F and oil was 210. I thought that was kinda high.. but reading you let your oil temps get to 260 before you worry! hell im good! lol

I have accessport and all stock cooling system..

 

From what I have found (read), synthetic oil is good up to 260-280F max. I read a few article on baja racing trucks and they are okay with average oil temps of 260-270F running fully synthetic. I am running Rotella T6 5W-40 at the moment. The dual cooler will cool oil and coolant at the same time but I don't know if it will be enough to drop my coolant and oil temps at the limit. Only one way to find out I guess.

As much as I hate the hood spacer mod I may give it a try to see if it allows heat to escape the engine bay.

I am also looking to free up space behind the radiator as well so I am going back to my battery relocation plans.

 

do one thing at the time.
DO NOT REMOVE THE THERMOSTAT__THE ENGINE WILL OVERHEAT.
try the second radiator 1st,
oem fans turn on at little over 200F

 

Hi Denny..

I am curious to know how removing a thermostat will over heat the engine ..

I would have thought by removing it you may 'over cool' the engine as with a TS installed it opens and closes to maintain a certain Temp???

I dunno...Just interested....

 

Think about how the coolant circulates...with and without the thermostat....


No thermostat won't work unless you plug the bypass hole....

 

exactly ---Thanks Dan.

Our engine has a coolant bypass system that is designed to recirculate the coolant in the engine (shuts off radiator flow) until a certain temp is reached. With the the thermostat removed that system will always be open.
Our thermostat has 2 valves on it. One on top and the other on the bottom part. When the top one opens the bottom one closes and shuts that bypass circulation.
Never ever run the engine with the bypass system open all the time.

You know i have been thinking and I bet that if you replaced the oem radiator with a smaller one stood straight up, that would do the trick. Its all about air flow.
OD

 

Ah okay. Thanks for the input guys.

 

take koyo out put stock back in.. really..

then get back to us.


beers