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Cooling mods yet high temps.

Old 10-25-2018, 12:12 PM
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Cooling mods yet high temps.


Hi
​​​​​​So i put foam around the top, right, and bottom of my rad, cooling low fan mod, and I'm still seeing high engine coolant temps with obd2. it's currently 89 degrees but 90's are the norm. New radiator and coolant bottle came with the car. New mishimoto fans. New cooling hoses 04 mt 6sp

Last edited by Kamal El; 10-25-2018 at 12:16 PM.
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Old 10-25-2018, 12:18 PM
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This is going to be a really silly suggestion, but are the new fans blowing air in the correction direction, into the engine bay?
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Old 10-25-2018, 12:28 PM
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Idling temp 15min 89*
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Old 10-25-2018, 12:28 PM
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whats your oil temp read at?

and when you say cooling fan mod are you talking about the relay hack job or an ecu tune?
what coolant did you use? what brand rad? was the t-stat touched? is obd2 the only means you have of reading coolant temp?
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Old 10-25-2018, 12:30 PM
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Originally Posted by Loki View Post
This is going to be a really silly suggestion, but are the new fans blowing air in the correction direction, into the engine bay?
the plastic bag test confirms that yes they are blowing correctly
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Old 10-25-2018, 12:33 PM
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Originally Posted by sonicsdaman View Post
whats your oil temp read at?

and when you say cooling fan mod are you talking about the relay hack job or an ecu tune?
what coolant did you use? what brand rad? was the t-stat touched? is obd2 the only means you have of reading coolant temp?
relay hack
oem rad
i never changed thermostat thermostats i don't recall anyway
only obd
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Old 10-25-2018, 12:49 PM
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make sure you didn't swap the relays the wrong way and that they only turn on when the high temp should be on. I personally don't like or trust the relay hack.
also I don't know much about the mishimoto fans or if they have better or worst cfm number but why did you need to swap out from oem? FAL fans would have been my choice

have you done a system pressure test? did you burp the system? are you missing any of the plastic around the rad? do you have the AC on?
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Old 10-25-2018, 01:36 PM
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Originally Posted by sonicsdaman View Post
make sure you didn't swap the relays the wrong way and that they only turn on when the high temp should be on. I personally don't like or trust the relay hack.
also I don't know much about the mishimoto fans or if they have better or worst cfm number but why did you need to swap out from oem? FAL fans would have been my choice

have you done a system pressure test? did you burp the system? are you missing any of the plastic around the rad? do you have the AC on?

relay for fan 1
https://www.summitracing.com/parts/mio-mmfs-rx8-04
1800-1899cfm
Oem secondary fan died
No pressure test
Didn't burp according to the manual, used the heater and top off method
plastic? Underbody tray is there, oil coolers vented, I used foam pipe insulation

Last edited by Kamal El; 10-25-2018 at 01:41 PM.
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Old 10-25-2018, 01:44 PM
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Originally Posted by sonicsdaman View Post
whats your oil temp?
im only reading obd2 engine coolant
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Old 10-25-2018, 01:49 PM
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Is your fan shroud sitting hard up against the radiator ? If there is a gap you lose a heap of efficiency .
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Old 10-25-2018, 01:54 PM
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those "upgraded" fans are either not up to snuff. they shroud around the fans isn't properly seated on the rad letting air past. you have a blockage somewhere in the coolant system(t-stat stuck maybe?) or an air bubble. or something is wrong with the relay mod.

my oem fans would keep the car under 215 with the ac on in 95f temp
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Old 10-25-2018, 01:55 PM
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Originally Posted by Brettus View Post
Is your fan shroud sitting hard up against the radiator ? If there is a gap you lose a heap of efficiency .
Good point. I need to put that foam tape between the shroud and rad. I'll do that then read the temps again.
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Old 10-25-2018, 02:25 PM
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Originally Posted by sonicsdaman View Post
those "upgraded" fans are either not up to snuff. they shroud around the fans isn't properly seated on the rad letting air past. you have a blockage somewhere in the coolant system(t-stat stuck maybe?) or an air bubble. or something is wrong with the relay mod.

my oem fans would keep the car under 215 with the ac on in 95f temp
Im going to buy a new thermostat when i buy the secondary radiator.
As far as air, the tbody burping method involves using your bare hands to attach a hose spewing scalding hot "coolant" right?
my fan mod

i used this method

Last edited by Kamal El; 10-25-2018 at 02:38 PM.
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Old 10-25-2018, 03:21 PM
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I've refilled an rx8 from bone dry a dozen times maybe . By far and away the best way to do it is to remove the top hose coming from the heater . Then just fill her up while giving the main hose to the thermostat a squeeze every now and then .When you have header tank so you can't get anymore in it , reconnect heater hose ...go for a drive around the block (till up to temp) with heater on . Recheck level when you get back and .....done !
It really is that simple ...no burping ,and none of the pissing about BS that I see on here !
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Old 10-26-2018, 07:07 AM
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I would definitely get the Mishimoto thermostat. I actually run my REW swap on original 14 year old fans and in Florida, and I have no flash or hack cooling mods. When I sit at stop lights for extended periods of time, temps will hit 215 (high speed mode slowly gets me back below 210). Once I get driving, due to the lower opening thermostat, temps will drop as low as 170. Usually though I hover around 185-190. I do idle at about 1,800-2,000 RPMs so that doesn't help either.

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Old 10-26-2018, 07:21 AM
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Thermostats don't do a damned thing if your coolant temps are already over ~200F.
~200F is a perfectly acceptable temperature. Hell, seeing peaks of 220F are fine.
My OE thermostat hovers around 175F during the winter.
5F is almost meaningless when you're below 220*F.

Don't bother with an aftermarket thermostat.
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Old 10-26-2018, 07:23 AM
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Originally Posted by strokercharged95gt View Post
I would definitely get the Mishimoto thermostat. I actually run my REW swap on original 14 year old fans and in Florida, and I have no flash or hack cooling mods. When I sit at stop lights for extended periods of time, temps will hit 215 (high speed mode slowly gets me back below 210). Once I get driving, due to the lower opening thermostat, temps will drop as low as 170. Usually though I hover around 185-190. I do idle at about 1,800-2,000 RPMs so that doesn't help either.
That's with the ac on right?
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Old 10-26-2018, 07:59 AM
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Originally Posted by NotAPreppie View Post
Thermostats don't do a damned thing if your coolant temps are already over ~200F.
~200F is a perfectly acceptable temperature. Hell, seeing peaks of 220F are fine.
My OE thermostat hovers around 175F during the winter.
5F is almost meaningless when you're below 220*F.

Don't bother with an aftermarket thermostat.
If you are driving around and getting air to the radiator and your car stays above 200 then I agree a thermostat won't help you much. But if you are driving around and the car cools enough to begin shutting the thermostat then it will help.

I have even logged vertical intercooler and stock thermostat vs horizontal intercooler and Mishimoto thermostat a few days apart in the same temperature. Forget the first data points as the car was just idling in my driveway.

You can easily see my driving around temps were considerably lower. Again this is only driving around temp, it will not help you in rush hour or stop and go traffic.

I use my AC in the summer and not much in the winter.

I also don't think you can use Chicago winters as a go by to test a "cooling" system.


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Old 10-26-2018, 10:30 AM
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Originally Posted by strokercharged95gt View Post
If you are driving around and getting air to the radiator and your car stays above 200 then I agree a thermostat won't help you much. But if you are driving around and the car cools enough to begin shutting the thermostat then it will help.
How will it help? What is the net benefit? If 200 is perfectly acceptable, how is lower than that demonstrably better? It isn't. It's actually potentially worse as carbon build-up is worse at lower temperatures.

Originally Posted by strokercharged95gt View Post
I have even logged vertical intercooler and stock thermostat vs horizontal intercooler and Mishimoto thermostat a few days apart in the same temperature. Forget the first data points as the car was just idling in my driveway.

You can easily see my driving around temps were considerably lower. Again this is only driving around temp, it will not help you in rush hour or stop and go traffic.

I use my AC in the summer and not much in the winter.
Repeat after me:
The plural of "anecdote" is not "evidence". There are no experimental controls. There are no variables addressed. Also, even if there were, there's no guarantee that the model that you're trying to extrapolate out to NA situations will even apply since your setup is significantly different from anybody that isn't turbocharged.

Originally Posted by strokercharged95gt View Post
I also don't think you can use Chicago winters as a go by to test a "cooling" system.
It's a great way of finding the thermostat opening temperature. If the OE thermostat opens as early as 175 then how much benefit are you getting with a thermostat that opens a whole 5 degrees lower?
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Old 10-26-2018, 03:32 PM
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You've won me over, thermostats don't work.
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Old 10-26-2018, 03:37 PM
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Originally Posted by strokercharged95gt View Post

I have even logged vertical intercooler and stock thermostat vs horizontal intercooler and Mishimoto thermostat a few days apart in the same temperature. Forget the first data points as the car was just idling in my driveway.

You can easily see my driving around temps were considerably lower. Again this is only driving around temp, it will not help you in rush hour or stop and go traffic.



The v mount looks pretty good ! ............ with the FMIC did you have a big IC blocking the rad all the way down to the undertray ?
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Old 10-26-2018, 04:31 PM
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Originally Posted by Brettus View Post
The v mount looks pretty good ! ............ with the FMIC did you have a big IC blocking the rad all the way down to the undertray ?
This is like 2-3 year old graph, but yes the front mount was blocking the radiator.

So I moved the intercooler to horizontal/flat replacing the undertray and changed to a Mishimoto thermostat. I run it like this now. As you would expect, you sacrifice air temp for water temp. Driving around with water temps of 200-210 were reduced to 180-185.
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Old 10-26-2018, 04:56 PM
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Originally Posted by strokercharged95gt View Post
This is like 2-3 year old graph, but yes the front mount was blocking the radiator.

So I moved the intercooler to horizontal/flat replacing the undertray and changed to a Mishimoto thermostat. I run it like this now. As you would expect, you sacrifice air temp for water temp. Driving around with water temps of 200-210 were reduced to 180-185.
I had same problem when I had a big (600x300) IC . Went with a smaller one and lifted it up as high as possible to get air to the radiator. That worked for cooling but the intercooler is now marginal for flow at higher boost . I'm currently redoing it with a high flow intercooler that I can still mount vertically.
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Old 10-26-2018, 10:42 PM
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Originally Posted by strokercharged95gt View Post
you've won me over, thermostats don't work.
:d:
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Old 10-26-2018, 11:34 PM
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is 212F considered ok ?
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