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Radiator fan EJ swap, between engine and radiator


presslab
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I'm finishing up my EJ20G swap and I'm looking into what radiator fan to get. It looks like I can fit a 2" thick one between the EA82T (2-row) radiator and the EJ20G engine. I can't really put one on front as I have the trans cooler and A/C condenser, and I'm not getting rid of A/C.

 

Anyone else put a fan between the engine and radiator?

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I'm looking at this Spal fan.

 

51Rgmcw0RUL._SL500_AA300_.jpg

http://www.amazon.com/gp/product/B003PB433Q/ref=oh_o00_s00_i01_details

 

Looks like I can fit two between the radiator and engine. I'm pretty sure it will work on the driver's side, on the other side the acorn nut for the power steering might interfere, but I can always put a normal nut on there to get a little more clearance.

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I have a stock accessory fan on one end and a fan from a car I found in the junkyard (I aint sayin what it came from), but its a 10in fan. I'm looking at aftermarket 10in fans to replace both, something like what you posted.

 

The only thing I had to relocate were my Hella Supertones.

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SPALs are nice. But FYI, straight-blade fans are VERY loud. We have a pair on the Ziptie Rally #171....I'd think twice before using them on a DD, depending on how much time you spend with the fan on.

 

Thanks for the info. I see SPAL has a two-speed fan controller... Maybe it would make sense to use something like this, so with A/C on it would be on low, and when the thermoswitch kicks in it will be on high.

 

I was thinking if I had two fans I would have one on for A/C and both on for thermoswitch. Maybe it would make more sense to have both on low for A/C and both on high for thermoswitch.

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Something you might consider, that I saw GM use, is for low, the fans are run in series, for high, they are run parallel. Something I'm thinking about.

 

 

That's a good idea, I'll see if I can rig that up with some relays. I wonder if there is a dual temperature thermoswitch that fits the stock M16x1.5 hole...

 

I found this SPAL curved blade fan, same size as the above one; should be quieter and it seems to flow a bit more air even:

30100411.jpg

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I got my fans, they're nice! It looks like the two 11" will fit just fine. I need to finish the brackets, and then it's on to the wiring.

 

I bought this relay box ('98 Toyota Corolla) for $8.50 shipped :brow: on eBay:

 

$(KGrHqVHJCcE9BfSBbnLBPbMLR7PDg~~60_58.JPG

 

 

I'll need the three lefthand relays for the dual speed fan control, and the right relay is a bonus.

 

Still of question is how I will hook up the thermoswitch. I can't find any dual-temp thermoswitches that will fit. So I'm thinking of using the stock thermoswitch (and A/C) for the low speed, and then using the ECU fan output for high speed.

 

Maybe use the Hyundai thermoswitch like Jeszek:

http://www.ultimatesubaru.org/forum/showthread.php?t=128177&page=3

 

Anyone know what temp will trigger the ECU to turn on the fan output?

Edited by presslab
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Yeah but what if the engine is real hot? I guess I could turn the A/C on to get the high speed to kick on, but this seems counterproductive.

 

My VW van has a two speed thermoswitch and it works well. I'd like to reproduce something like this if I can on the Subaru.

 

I've got the two fans mounted, looking good! At least 1/8" of clearance. :drunk:

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Well, ok I think I'm stupid. :o After reviewing the wiring diagram some more it looks to me like the turbo ECUs already have support for two speed fans. The cool part about using the ECU is it turns the fans off (sometimes) once the car starts moving, so the fan's aren't whirring away when tooling down the road with A/C on.

 

I think I can plumb my new relay box right into the ECU and have it do the series/parallel thing; although, the WRX has fans that run two speeds, and does not series/parallel them.

 

 

However, my JDM Impreza service manual does not have the cooling section in it, so I'm a bit in the dark here. Anyone have this for a '94 JDM Impreza? The attachment is for a USDM 2002 Impreza, I guess it is similar.

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  • 2 weeks later...

Alrighty, I've got the fans all wired up. I used the old fan connector and used the fan positive switched ign power from there to power the relays (so the fans can't turn on during cranking) and the fan negative connects to the "high speed" output from the ECU. This causes the fans to run high speed when the A/C switch triggers due to high pressure, just like the JDM diagram shows.

 

I basically copied the GM wiring diagram for the new relays, but I needed to add a diode between the ECU high speed and low speed outputs. This is so that if the high speed output is on, it will also force the low speed output on. Without the diode only one fan would work at high speed.

 

On low speed, the fans are quiet! Can't hear them over the engine idling, but they blow a fair amount of air. On high, the fans are audible, but not loud. Again these are two 11" Spal curved blade fans.

 

And I've got my A/C tubes all welded up, and A/C charged, only to find that the compressor is bad! :Flame: The "A/C cut" relay is also giving me fits, it looks like I'll need to change the wiring on this relay to work with the new ECU.

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