DIY: 170F Thermostat Mod - Genesis Forum: GenCoupe Hyundai Genesis Forums

GenisisPrincess · 08-20-2012, 02:21 PM

Ok I live in very Hot Summer of Texas. GenCoupe baking in heat from 100+ days and so decided to to see if this would work on this car as it has on my last few.

The principal here is to lower opening temps and not throw any codes or create havoc of any kind. With a 8+ degree cooler running car makes other things better such as heat felt at firewall on feet, A/C cooler, more power etc.

So here goes:

Tools:
2 - Flat head screw drivers (tiny and standard)
2 - Pliers (needle nose and standard)
Metal snips
Soft Clamp for holding thermostat

THIS IS FOR 3.8 ONLY. but the mod can be applied to 2.0 using method and different parts.

Parts: Factory OEM Thermostat 25500-3C130 ($22) and Stant #48457 ($16)Stant Part 48457
I bought new factory one. Reason: I have a stocker to go back to and I could do the mod and install on car later.

Process:
Remove Spring off stock stat by simply (not really PATIENTLY) spining off the spring from cage.
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Then Cannibalize the $16 170F thermostat, retrieving the spring by cutting metal frame with snips:
[IMG]

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Then Thread the new spring on OEM cage. Test in pot of hot water make sure it opens and closes:

Starts to Open at 175F:
[IMG]

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Fully Open at 184F:

Enjoy.

Installation: Tools, flat head screw driver, 12mm ratcheting box end wrench, towels

Drain fluid. Make sure car is cold.

[IMG]

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Remove bolt.

Loosen 3 bolts on top and bottom of thermostat housing. They were not very (tight two finger pull)
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From under car to get other 2
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This is the factory stat in place after housing removed. Note the location of jiggle pin.
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This is data shot on 95F day. Idle for 30mins. Hood closed. AC turned on (188.6F) and AC off (204.8F). This is a stock ECU non tuned as tuned cars run 20% fan loads so I'm told.
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**Jorge@UNIQPERFORMANCE** · 08-20-2012, 02:26 PM

See what happens when you stay home on weekdays? lol

So what's the opening temp for OEM thermos?

GenisisPrincess · 08-20-2012, 02:38 PM

Quote:

Originally Posted by DevilDog1775

See what happens when you stay home on weekdays? lol

So what's the opening temp for OEM thermos?

I know been busy...grin. Stocker is (82C) 180F but starts opening at 186F fully open at 195F

Red Raspberry · 08-20-2012, 02:45 PM

If you have the AC on good luck keeping it below 190F.

GenisisPrincess · 08-20-2012, 02:56 PM

Quote:

Originally Posted by Red Raspberry

If you have the AC on good luck keeping it below 190F.

I ScanTool logged (30mins after drive home from work) the car twice in garage hood down and the temps were higher at idle with the AC OFF than with the AC ON. The electric fans come on with the AC so it would drop the temps from 210F to 188F in about 1minute. This is with the factory stat in +90F ambient air. During that logging the electric fan never came on unless AC was on.

Red Raspberry · 08-20-2012, 02:59 PM

Well you can get the fan to come on sooner. Or install a manual switch fairly easily.

BRs tune have the low speed fan on all the time unless the AC is on. The the OEM fan logic takes over.

GenisisPrincess · 08-20-2012, 03:04 PM

Quote:

Originally Posted by Red Raspberry

Well you can get the fan to come on sooner. Or install a manual switch fairly easily.

BRs tune have the low speed fan on all the time unless the AC is on. The the OEM fan logic takes over.

Seriously? "COOOOOLLL" BR the only one? I'm getting SFR next month....hmmm

Sam@PRW · 08-20-2012, 03:32 PM

Ours does it too. Most of the reflashes do.

cris90 · 08-20-2012, 04:03 PM

this is great and all but grimmspeed has a thermostat for $52 that opens at 160...

Red Raspberry · 08-20-2012, 04:27 PM

I don't like the fan on all the time. I would rather have a manual switch or get a manual temp controller.

When it's cooler out there is no need for the fan to be running. And the BR tune has the low speed fan running no matter what the vehicle speed.

GenisisPrincess · 08-20-2012, 05:15 PM

Red I agree.

I haven't ran the car hotter than 220 yet to see if the ECU trips the fans without AC on.

Is it possible that the fan control is there and the tuners just cant own it? It would make sense to me to that a fan duty cycle (20-100%) vs coolant temp (100-240F) say an 6x6 cell table would be there in ECU programming to modify. A static X% is a step in right direction but it would be best to regulate the fans in order to maintain longevity of fan motor and other AMP needs.

cris90 · 08-20-2012, 05:20 PM

found somethign better

http://www.flex-a-lite.com/auto/html...cessories.html

Attaches to or near the electric engine-cooling fan. Senses coolant temp. via the radiator core and sets fan speed from 60% to 100%, depending on built-in fan thermostat setting. Thermostat range: 155 - 220 degrees Fahrenheit. Allows greater control over engine temp: reduces charging spikes and current load on charging system. 45 amp max. load. Directs fan to run for 30 seconds after vehicle is turned off.

Red Raspberry · 08-20-2012, 06:35 PM

You can get a thermostatic switch that inserts into the upper radiator hose connector area. Then wire this to ground and on the other side of the switch to the hi speed fan relay coil ground. If you also want to manually control the the high speed fan then run a ground to the same thermostatic switch through a rocker switch.

Here's a link to the type of fan I'm talking about. Very good price too.

Derale Adjustable Fan-Control Thermostat with Radiator Hose Probe

cris90 · 08-20-2012, 07:38 PM

ya i saw that one too.. that one isn't as good.

Derale Cooling Products 16788 - Derale Performance High-Amperage Adjustable Fan Controllers - Overview - SummitRacing.com

it automatically turns with a/c

i like the flex light works a turbo timer runs 30secs after caar turns off to cool little more

Red Raspberry · 08-21-2012, 03:49 AM

That's overkill if you already have the fan wiring in place. No need for high amperage relay when all you are needing to do is ground a relay coil, ~1A. It's also a $100 more......

cris90 · 08-21-2012, 04:22 AM

ya thats true.... but flex-lite and the higher derale also has a a/c override, so once the a/c on your car is on your fan turns on by default.

i'd consider the smalled one to use for a oil cooler that be handy in that case i think.

you really enver want to set it to turn on below 150-160 or not in the winter you'll take forever to warm up the car and be in that safegaurd limp mode.

Red Raspberry · 08-21-2012, 04:32 AM

Stock and with the BR tune when the AC mode is on, the low speed fan is on all the time at speeds under 35 mph. Once above 35 mph the low speed fan turns off and the AC high pressure switch will turn the high speed fan on and off.

The high speed fan only runs with the AC mode on. The low speed fan runs either with AC mode on or when coolant temp exceeds ~200F.

cris90 · 08-21-2012, 04:49 AM

i don't have tune...

i'd consider this, not so much as a add on control, but as a complete replacement over the stock system control. Set it to ~160F on, high, a/c on high, and with a grimmspeed thermostat of 160 it always hold the water temp at 160, and very unlikely ever go over.

Red Raspberry · 08-21-2012, 04:52 AM

Don't count on 160F without a major radiator upgrade.

I just ordered the fan controller I posted above. I had one on my last car and it worked great. But I need to disable the BR tune low speed fan on all the time feature.

cris90 · 08-21-2012, 04:57 AM

Quote:

Originally Posted by Red Raspberry

Don't count on 160F without a major radiator upgrade.

I just ordered the fan controller I posted above. I had one on my last car and it worked great. But I need to disable the BR tune low speed fan on all the time feature.

why don't you just unplug the harness, and splice the module straight into the fan? disregard the slow and fast mod, and just tap it into the wires for "fast".

i doubt it's voltage regualted is it?

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