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Old 07-08-2020, 11:09 AM   #476
wobbletop
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Quote:
Originally Posted by jokem View Post
I was taking a look at the cooling diagram:


In that diagram, what's the difference between cylinder block (11 12) and cylinder jacket (10 13)?
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Old 07-08-2020, 03:05 PM   #477
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Quote:
Originally Posted by RavensFan7 View Post
I’d say just based off looking at the port/hose sizes, atleast 75% to the water pump, 25% to the radiator. Maybe 80/20. Not really sure. Definitely most.

The amount that would actually make it through the radiator would be so small, I can’t see it making any difference over the normal routing into the heater core return.




20%-25% can change the dynamics just enough for it to be beneficial. ~21% is the difference between Dom's plug ID (10mm) and Subaru's plug ID (12.7, iirc) and many feel this difference is the secret to the magic of Dom's kit (there's no argument from me that there will be differences). I can't say I know how it changes when it comes to this routing but again I lean on the fact that's how Subaru set it up.
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Old 07-08-2020, 07:56 PM   #478
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Quote:
Originally Posted by wobbletop View Post
In that diagram, what's the difference between cylinder block (11 12) and cylinder jacket (10 13)?
The cylinder block would be each side of the engine (case halves). The cylinder jacket would likely be the coolant passage ways from the cylinder block to the cylinder heads (9 and 14).
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Old 08-05-2020, 02:59 AM   #479
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Quote:
Originally Posted by Samurai Jack View Post
What he ^^^^ said.

Can you build one yourself? Sure.
How much time and effort are you going to spend running down the right parts, lengths, etc.? How much is your time worth? ....
I bought a car with a blown JDM Legacy GT EJ20X engine. The engine came with the fitting for the cooling mod. The owner had blocked off this fitting with a rubber cap. I am unsure of whether the JDM legacy comes with this fitting pre-installed or if the previous owner of the engine had started to install the mod and didn't go for it.

Aside from that fitting which I already had, I spent $10 at autozone for the 5/8 inch heater hose and 5/8 inch tee fitting.

Last edited by sebastian323; 08-05-2020 at 03:05 AM.
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Old 08-05-2020, 12:02 PM   #480
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Originally Posted by sebastian323 View Post
I bought a car with a blown JDM Legacy GT EJ20X engine. The engine came with the fitting for the cooling mod. The owner had blocked off this fitting with a rubber cap. I am unsure of whether the JDM legacy comes with this fitting pre-installed or if the previous owner of the engine had started to install the mod and didn't go for it.

Aside from that fitting which I already had, I spent $10 at autozone for the 5/8 inch heater hose and 5/8 inch tee fitting.
Looking at various pictures of the EJ20X from various importers, they all appear to have that plug with a hacked of hose.

I'm going to assume that is the factory Subaru plug, as various importer sites all show the same plug. I'm very interested to know where that hose routes to since a quick search revealed these engines are single turbo.
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Old 08-05-2020, 12:11 PM   #481
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Looking at some pics it almost looks like it goes to the OEM oil cooler around the oil filter. In these pics it looks like it connect to a cylindrical cooler. Not sure if it is a oil cooler (looks like it). Or could be a heater heat sink or something. Or it aculally looks more like it goes to some kind of a gold metallic diaphragm looking actuator for something I have no idea.

https://www.ebay.com/p/6020409103





Last edited by BlackFighter; 08-06-2020 at 11:15 AM.
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Old 08-09-2020, 02:11 PM   #482
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Originally Posted by BlackFighter View Post
Looking at some pics it almost looks like it goes to the OEM oil cooler around the oil filter. In these pics it looks like it connect to a cylindrical cooler. Not sure if it is a oil cooler (looks like it). Or could be a heater heat sink or something. Or it aculally looks more like it goes to some kind of a gold metallic diaphragm looking actuator for something I have no idea.
That appears to be a transmission fluid cooler. You can see that the engine in your picture is an automatic because you can see the ATF fluid pan
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Old 08-10-2020, 09:26 AM   #483
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Well there you go. We figured it out. That port was designed to cool of your auto tranny.
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Old 08-10-2020, 10:16 AM   #484
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Originally Posted by BlackFighter View Post
Well there you go. We figured it out. That port was designed to cool of your auto tranny.
Or the second turbo on twin turbo models.

It's just a shame Subaru showed a total and complete lack of regard for the plugs ID....
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Old 08-10-2020, 10:42 AM   #485
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Quote:
Originally Posted by sebastian323 View Post
That appears to be a transmission fluid cooler. You can see that the engine in your picture is an automatic because you can see the ATF fluid pan
Got a friend who also stated the same when we were discussing this topic. He's pretty familiar with those legacy Legacy engines.
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Old 08-10-2020, 11:10 AM   #486
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So it looks like the coolant from the block goes to the gold diaphragm or thermostat, and controls the tranny fluid to go in the white/silver metallic cylindrical cooler to the left of the gold part.
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Old 08-10-2020, 11:18 AM   #487
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Single vs twin turbo. So ya it was used for twin turbo or to cool of the auto tranny.








Last edited by BlackFighter; 08-10-2020 at 11:24 AM.
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Old 12-10-2020, 01:33 PM   #488
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so I have my own cheapo version of the mod. I got a simple coolant "T" and the fitting from an EJ20X i had lying around. I angled the T in a vertical format to increase clearance with the steering rack,,, some correctly said that this positioning will disable the heater core. I apparently can now only get the heater to work when the car is moving and the thermostat is more closed.


How is the heater working on your cylinder 4 cooling modded car ?
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Old 12-10-2020, 01:57 PM   #489
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Quote:
Originally Posted by sebastian323 View Post
so I have my own cheapo version of the mod. I got a simple coolant "T" and the fitting from an EJ20X i had lying around. I angled the T in a vertical format to increase clearance with the steering rack,,, some correctly said that this positioning will disable the heater core. I apparently can now only get the heater to work when the car is moving and the thermostat is more closed.


How is the heater working on your cylinder 4 cooling modded car ?
I've had the Dom piece installed for over a year and never had issues with my heater.
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Old 12-10-2020, 02:09 PM   #490
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I have the VEMS kit as Dom's kit was sold out at the time and my heater works but not as hot as it was before.
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Old 12-10-2020, 02:11 PM   #491
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Using a DOM kit (installed per their instructions) over the past year and have had no issues. All I did was swap the silicone strait hose out for an angle formed EPDM hose. My hose material change would not have any impact on coolant flow but it did offer extra clearance to the steering joint.
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Old 12-10-2020, 02:55 PM   #492
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Re: heater performance

There's probably a reason why Subaru T'ed their left side turbo coolant return line to the rights side coolant return. Surely, Subaru must have known there was a shorter path with the coolant lines being so close???
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Old 12-10-2020, 03:26 PM   #493
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Quote:
Originally Posted by viper_crazy View Post
Re: heater performance

There's probably a reason why Subaru T'ed their left side turbo coolant return line to the rights side coolant return. Surely, Subaru must have known there was a shorter path with the coolant lines being so close???


Agreed and in the spring I'm planning on routing it to the turbo side when I replace my radiator.
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Old 12-26-2020, 08:45 AM   #494
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Quote:
Originally Posted by JarHarms View Post
Using a DOM kit (installed per their instructions) over the past year and have had no issues. All I did was swap the silicone strait hose out for an angle formed EPDM hose. My hose material change would not have any impact on coolant flow but it did offer extra clearance to the steering joint.

Any details on the formed EPDM hose you used? Please and thanks.
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Old 12-26-2020, 02:44 PM   #495
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Been shopping for a suitable jdm engine swap and noticed the jdm 08-14 wrx ej20x with no air pump came with this mod as standard. As you can actually order this from a dealer given you have a part number.
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Old 12-27-2020, 09:48 AM   #496
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Quote:
Originally Posted by sebastian323 View Post
so I have my own cheapo version of the mod. I got a simple coolant "T" and the fitting from an EJ20X i had lying around. I angled the T in a vertical format to increase clearance with the steering rack,,, some correctly said that this positioning will disable the heater core. I apparently can now only get the heater to work when the car is moving and the thermostat is more closed.


How is the heater working on your cylinder 4 cooling modded car ?

I have the Torque Solutions version of the kit because Dom's was out of stock everywhere when I was buying and my heat works just fine.
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Old 12-29-2020, 02:00 PM   #497
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Originally Posted by Underdog_LGT View Post
Any details on the formed EPDM hose you used? Please and thanks.
Gates 28466, you will have to trim some off the legs to get the perfect fit.
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Old 09-23-2021, 12:57 PM   #498
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Originally Posted by WRXnick16 View Post
First off, thanks to Dom for doing the research and work to offer this product to the community. And for providing an explanation of how the kit works. Without a question, he has more knowledge and experience with the EJ platform than most in this thread.

I didn't see this mentioned anywhere, but may have missed it with all of the derailing in this thread..

Did anyone notice that while the EGTs that he shared have a smaller delta and show lower temps for cylinder 4, the average EGT across the cylinders has increased by 18 degrees?

EGTs without the kit (848, 832, 827, 901) - AFR: 13.4
Min: 827
Max: 901
Avg: 852
Range: 74

EGTs with the kit (874, 862, 865, 882) - AFR: ??
Min: 862
Max: 882
Avg: 870.75
Range: 20



This could very well just be the result of his testing conditions. It would be insightful to know his testing methodology for the before & after EGT measurements. How were the EGTs measured? Were ELH or UELH used on the test car? What were the ambient temperatures? How long had the engine been running? Were the EGTs taken at idle, while driving, WOT? What were the coolant, oil, and IAT temperatures? What were the Air/Fuel ratios? Was there a single 'downstream' EGT measured as well? Obviously there are a lot of variables and not all of them are controllable, but they will impact the results.

The higher average could simply be the result of 'harsher' testing conditions and demonstrate that the kit is still able to lower the cylinder 4 temperature even as the temperatures of the other cylinders increase. The smaller delta across cylinders can offer an advantage for tuning and the lower temps for cylinder 4 may help keep it happier. I'm just curious if this impacts overall cooling or flow in a negative way. Just hoping to see some more testing results.

Has anyone monitored the change in avg/max coolant temp or EGT after adding the kit? Have the temps increased, decreased or stayed the same?

Sorry.. I have a science background and prefer to see data and controlled testing conditions

And for those that will say it:
... yes, I know I could/should spend the $85 for his kit, do the testing myself, and report back.

It's because you are taking hot water from cylinder 4 and return it directly to the engine, where the thermostat is, without flowing the water through the radiator first! So what you are doing, is constantly pumping into the engine hot water! This mod is a complete hack and only a person who doesn't know hot the system flows, would install it
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Old 08-07-2022, 01:44 AM   #499
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Quote:
Originally Posted by Fable1521 View Post
It's because you are taking hot water from cylinder 4 and return it directly to the engine, where the thermostat is, without flowing the water through the radiator first! So what you are doing, is constantly pumping into the engine hot water! This mod is a complete hack and only a person who doesn't know hot the system flows, would install it


I've always heard bad things about it but this thread has me for a loop
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Old 08-08-2023, 05:56 AM   #500
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Let's revive this thread a whole year later lol

Sorry is my following question has been already answered in a previous post, but 20 pages is quite a lot so I'll accept all the flame coming my way if that's the case - so here it goes.

If one were to go the OEM route and path (to the LH side turbo),
What are the parts needed to accomplish the mod (aside from the OEM fitting of course) and to what line do you tap into?
Any diagrams available?

Will the same sizes used on all available kits work while only needing to add a longer piece of hose, or there is a decrease in ID size somewhere along the OEM path?

Last edited by SullenSenium; 08-08-2023 at 09:25 AM.
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