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42mm rad but no change in coolant temp?

Posted: Sat Jun 13, 2015 7:28 pm
by IanR
Hey, I have a nb8b with added t25 turbo & IC, otherwise std.

The std radiator left the coolant temps between 95 and 100, no matter how easy I drive or how cold it is outside. Light throttle driving sees the fans on always.

I have installed a 42mm radiator and it has made zero difference. I have sat car running on steep incline, topped up overflow, let it cooled rerun...no change, sit 95-100 with fans on.

What have other people done to get air to the radiator or other suggestions, I thought the bigger rad would really change the hot running motor. Am I missing something.

Cheers.

Re: 42mm rad but no change in coolant temp?

Posted: Sat Jun 13, 2015 9:37 pm
by Nevyn72
Not all aftermarket radiators are created equal..... :wink:
What did you use?

How are you measuring the temperature and where from?

Re: 42mm rad but no change in coolant temp?

Posted: Sat Jun 13, 2015 11:07 pm
by Sailor
Is your waterpump and thermostat ok

Re: 42mm rad but no change in coolant temp?

Posted: Sun Jun 14, 2015 12:46 pm
by IanR
Yes, its a ebay chinarad. Measuring from the laptop with tunerstudio (megasquirt car)

Burped some more air from the system this am and was able to add heaps of water, holds 92deg w out fans so its better than before.

Anyone recommend a high flow or low temp thermostat?
http://www.ebay.com.au/itm/TRIDON-HIGH- ... 19e7b00cc4

Thanks for the input.

Re: 42mm rad but no change in coolant temp?

Posted: Sun Jun 14, 2015 12:56 pm
by NitroDann
low temp thermostat wont help if the one you have is lower than your coolant temp already. You will just be changing one thermostat that sits fully open for another one.

Re: 42mm rad but no change in coolant temp?

Posted: Sun Jun 14, 2015 1:47 pm
by Magpie
A cooler engine temp MAY produce more HP, but fuel economy/emissions will worsen. Just remember thermostats only control minimum temperature and just because you put a thermostat will a less opening temperature or a high flow does not imply you will get an overall temperature decrease.

But... if the engine runs too cool, thermal efficiency is lost, power is reduced and parts wear out quicker.

Re: 42mm rad but no change in coolant temp?

Posted: Sun Jun 14, 2015 1:54 pm
by manga_blue
IanR wrote:Anyone recommend a high flow or low temp thermostat?
http://www.ebay.com.au/itm/TRIDON-HIGH- ... 19e7b00cc4
I'm using that one. They used to be sold by MX5Mania. They're pretty good.

As others said, don't go low temp, it buggers up the mixtures. High flow is good though for a modded or tracked motor.

Re: 42mm rad but no change in coolant temp?

Posted: Sun Jun 14, 2015 2:08 pm
by Magpie
This is data from the recent JapNats at Queensland Raceway.

Air Intake Temp is down the left and speed across the top. The MAX water temp is in the body of the table. The car is running an OEM thermostat, PWR water/oil combo.

ImageWater Temp by Eipeip, on Flickr

Re: 42mm rad but no change in coolant temp?

Posted: Sun Jun 14, 2015 3:09 pm
by manga_blue

Re: 42mm rad but no change in coolant temp?

Posted: Sun Jun 14, 2015 6:44 pm
by IanR
High flow in the low 90 deg range is what makes sense from the info so far. I don't want it to run colder than 90 for efficiency but need but more ability to dump heat than Std setup.

Re: 42mm rad but no change in coolant temp?

Posted: Sun Jun 14, 2015 7:01 pm
by NitroDann
High temp stat won't help on your ecu equipped car

Re: 42mm rad but no change in coolant temp?

Posted: Sun Jun 14, 2015 8:20 pm
by IanR
Magpie wrote:This is data from the recent JapNats at Queensland Raceway.

Air Intake Temp is down the left and speed across the top. The MAX water temp is in the body of the table. The car is running an OEM thermostat, PWR water/oil combo.

ImageWater Temp by Eipeip, on Flickr



looks pretty stable. good setup then.

Re: 42mm rad but no change in coolant temp?

Posted: Sun Jun 14, 2015 8:25 pm
by IanR
NitroDann wrote:low temp thermostat wont help

NitroDann wrote:High temp stat won't help on your ecu equipped car


You like the oem one for the nb?

Re: 42mm rad but no change in coolant temp?

Posted: Mon Jun 15, 2015 6:27 pm
by beavis

Re: 42mm rad but no change in coolant temp?

Posted: Mon Jun 15, 2015 7:40 pm
by manga_blue
beavis wrote:http://www.miataturbo.net/race-prep-75/miata-cooling-system-thread-79930/

That's inserting reasonable and informed commentary into the thread, Brendan. Forum rules ban that. :evil: