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Thermostat for EJ25

Featured Replies

My buggy currently does not have a thermostat in it (the engine was built by Outfront motorsports and they specialize in sandrail applications where they don't recommend running one). I want to go ahead and install one, but what is the factory thermostat temperature? What other options are available? I'd like something around 180 (edit,.. I'm thinking lower now actually 150 maybe if possible).

Edited by Speedbuggy

the factory OEM thermostats are better than aftermarkets, you can see pictures on here comparing the two - the visual alone says alot. i guess you know but there's a thermostat housing that bolts to the water pump. i believe 180 is correct.

  • Author

whoops, just noticed I put this thread in the wrong section! Any mods want to move it to the tech area?

 

Thanks for the info Gary, I'll search for a comparison.

If you want to install one, I would go with the genuine Subaru thermostat. If you're running in hot temps at high loads in the buggy then you might as well leave it out for less restriction as under those conditions it would probably generate enough heat that the thermostat would simply be fully open all the time anyway. In those conditions a person might run just distilled or RO/deionized water with water wetter instead of any glycol as well.

It's been said probably at least a hundred times here that dealer t-stats are better. I put one from a reputable aftermarket supplier in a couple days ago, and it wouldn't open. It was the same size/dimensions/fit and finish as a dealer one. I replaced it with a dealer one, and it opened fine. Sometimes I need reminders like that:)

 

Jacob

My buggy currently does not have a thermostat in it (the engine was built by Outfront motorsports and they specialize in sandrail applications where they don't recommend running one).

 

i don't know much about sandrails, but if the engine does not have a t-stat, will it ever get up to normal operating temp? will it constantly run in open loop? i guess fuel economy isn't really a concern but what about power, isn't that affected?

 

just wondering.

It will go closed loop above around 150F, provided all the required sensors and such were hooked up. I mean the thing may not have the o2 sensors and such wired in anyway. I think the idea in not running a thermostat is that a sandrail is going to be running at high load, possibly quite near full throttle, for extended periods of time in hot weather. And in that case the thermostat is just going to be full open anyway, so you can avoid the restriction of having the thermostat in the system by just eliminating it.

  • Author

Like I said, the company who built it normally builds them for sandrails so they don't put thermostats in them. It DOES get up to full operating temperature without, it just takes a pretty long time.. 10 minutes of drive time even during the summer. They're also run with a stand alone ECU, so there's no 'codes' to worry about or anything. Outfront (the company who built mine) use the EMS Stinger (http://www.fuel-injection.com/frameindex.htm ).

 

However, my Buggy is NOT a sandrail, and is set up strictly for street use (it's more of a HotRod at heart than a Dune Buggy). Driveability is a concern for me (the sandrail guys don't mind starting it up and letting it warm up for a few minutes before driving, etc). So I want to put in a thermostat on mine. However, I would like it to open up pretty early. What temperatures are available in an OEM unit?

Edited by Speedbuggy

I think the genuine thermostat starts to crack open around 172F or 176F or something like that is pretty much fully open above 182F or so if I remember correctly. I don't think they have any temperature options in the genuine thermostat, unless maybe the STi's or spec. C's might have a different temperature.

 

As long as you have a sufficient bypass flow through the heater core, etc., having the thermostat should be ok, since the coolant can just then run through the bypass when the thermostat is closed.

 

You could also put in the Subaru block heater, those are only like $25, and then plug that in a couple hours before leaving home to help it get up to temp faster as well and warm the engine oil, etc.

 

So what kind of transmission does she have in there?

  • Author
I think the genuine thermostat starts to crack open around 172F or 176F or something like that is pretty much fully open above 182F or so if I remember correctly. I don't think they have any temperature options in the genuine thermostat, unless maybe the STi's or spec. C's might have a different temperature.

 

As long as you have a sufficient bypass flow through the heater core, etc., having the thermostat should be ok, since the coolant can just then run through the bypass when the thermostat is closed.

 

You could also put in the Subaru block heater, those are only like $25, and then plug that in a couple hours before leaving home to help it get up to temp faster as well and warm the engine oil, etc.

 

So what kind of transmission does she have in there?

 

Transaxle is a beefed up Volkswagen Beetle deal with Porsche 930 CVs and axles.

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