upgrading cooling system for NA legacy

mellow65 · Post by **mellow65** » Mon Aug 25, 2008 9:13 am

Give me some ideas for upgrading my stock cooling system for my 90 NA 5 speed legacy. I swapped a 2.5 in and do rallying and so far haven't had over heating (knock on wood) but it just runs hotter then i would like.

i have looked at the koyo but as far as i can tell they only have it for the turbo legacy.

one random idea i had was a newer STI rad, it isn't like the turbo legacys or wrxs it has a fill cap on the top. Just not to sure about fitting and don't really have the scratch to buy one and find out it doesn't fit.

any ideas would help

Post by **Legacy777** » Mon Aug 25, 2008 5:51 pm

I guess my question would be, how do you know you're running hotter then you'd like to?

I too have looked for an aftermarket or upgraded radiator, and haven't found much for the n/a cars.

I have the turbo motor in my car with the n/a radiator, and I haven't had any overheating or higher then normal temps. I've been pretty impressed with the cooling system.

The ECU regulates temps between 190 and 200 deg F via the radiator fans. The thermostat limits your low end coolant temps around 180 deg F.

I've looked at the ECU via the select monitor and don't have any issues.

If you want to try and get the fans to be faster, there's wiring on the pressure sensor you could tap into in the AC system to speed the fans up.

Other thing to note. I am running Redline water wetter. Whether that has helped or not....I can't say....but the theory behind how it works is sound.

mellow65 · Post by **mellow65** » Mon Aug 25, 2008 6:10 pm

Legacy777 wrote:I guess my question would be, how do you know you're running hotter then you'd like to?

after market gauges

I too have looked for an aftermarket or upgraded radiator, and haven't found much for the n/a cars.

I have the turbo motor in my car with the n/a radiator, and I haven't had any overheating or higher then normal temps. I've been pretty impressed with the cooling system.

The ECU regulates temps between 190 and 200 deg F via the radiator fans. The thermostat limits your low end coolant temps around 180 deg F.

I've looked at the ECU via the select monitor and don't have any issues.

If you want to try and get the fans to be faster, there's wiring on the pressure sensor you could tap into in the AC system to speed the fans up.

Other thing to note. I am running Redline water wetter. Whether that has helped or not....I can't say....but the theory behind how it works is sound.

i'm running the red line stuff also, like you say if it does what it says it would be nice.

i don't think the fan trick would work for me. i just need a larger cooling area.

in every day normal driving i can't complain about the cooling system as most people don't complain about it either. it's on stage that gets me thinking about it. some times i'm pushing it hard for 20-25 mins. and it then when it's a 100 degrees out that it makes me wish i had more cooling. [/quote]

Post by **Legacy777** » Mon Aug 25, 2008 6:14 pm

mellow65 wrote:
Legacy777 wrote:I guess my question would be, how do you know you're running hotter then you'd like to?
after market gauges

Are your aftermarket gauges calibrated properly? Are you using a separate coolant temp sensor for those aftermarket gauges?

What temps are you seeing?

mellow65 · Post by **mellow65** » Mon Aug 25, 2008 6:23 pm

Legacy777 wrote:
mellow65 wrote:
Legacy777 wrote:I guess my question would be, how do you know you're running hotter then you'd like to?
after market gauges

Are your aftermarket gauges calibrated properly? Are you using a separate coolant temp sensor for those aftermarket gauges?

What temps are you seeing?

well i would hope they would calibrated right. They were new and never used. I'm using the sensor that came with the gauge.

and really i'm not running crazy hot temps, i think (because they sit in front of my codriver) they get to the 215+ range, which i'm sure is completely normal, but it's just the thought of wanting a little more. it's one more step to to building a as trouble free rally car as i can. it would just ease my mind.

Post by **Legacy777** » Mon Aug 25, 2008 6:27 pm

Where did you tap/install the aftermarket gauge sensor?

I agree, 215 isn't too bad, but any more you can get is nice.

What I'd love to find is a radiator that is a wider core but still same overall dimensions....but I'm not sure if something like that exists.

mellow65 · Post by **mellow65** » Mon Aug 25, 2008 6:37 pm

Legacy777 wrote:Where did you tap/install the aftermarket gauge sensor?

I agree, 215 isn't too bad, but any more you can get is nice.

What I'd love to find is a radiator that is a wider core but still same overall dimensions....but I'm not sure if something like that exists.

i got an adaptor from auto meter that goes in line with you heater lines, so it takes it right as it's coming out of the motor. it was the best place i could find and i was in a time crunch to get it ready for the next race so there it stays.

i'm going to do some searching with the sti/wrx stuff. maybe i can find one locally that i can measure and see.

mellow65 · Post by **mellow65** » Tue Aug 26, 2008 1:30 am

well i have someone on nasioc measuring a sti radiator. i did some online searching for the difference between a impreza radiator and a legacy, and really there isn't much of a difference in size. the imprezas were about an inch wider and an inch shorter, i think that would be easy to work with mounts to make that fit in a legacy. so if you can do that then you could get a koyo radiator for the impreza and mount it in the legacy. but i don't really want to drop $300+- for a koyo radiator just to find it doesn't fit.

next i need to get the measurements for the sti and see if that will fit or find an impreza radiator and see what it looks like in a legacy. and from what i found the impreza radiators had the same part number from 93 to 01. well that's at least what autozone.com said.

Post by **Legacy777** » Tue Aug 26, 2008 5:53 pm

Well, let me know what you find out. I'm definitely interested. It's something I've thought about, and wouldn't mind some additional cooling capacity if I could get some.

mellow65 · Post by **mellow65** » Fri Aug 29, 2008 12:54 am

well the bad news is an impreza radiator doesn't fit in a legacy. oddly enough it was taller then the legacy so the hood wouldn't close. i'm sure you could modify the lower radiator support to sink in lower but i dont have that kind of time before my next race. So i'm back to square one.

maybe over the winter i will mess around with it some more. the two races left this year are closer to the end of it, so it should be much cooler.

but if i ever find something out i will let you know

SemperGuard · Post by **SemperGuard** » Mon Sep 01, 2008 6:25 pm

Legacy777 wrote:What I'd love to find is a radiator that is a wider core but still same overall dimensions....but I'm not sure if something like that exists.

96 and 97 2.5GT and Outback radiators are what you want. Same endtanks as all non-turbo 90-99 Legacy/Outback, but with a dual core. I never got a chance to test this at the track, because I haven't driven the car in about a year, but this is what you need. Replace the fan motors with 91-94 turbo ones and add the upper radiator shroud from a 90 for extra assurance. You end up with about 550 cc less cooling capacity than a stock 91-94 radiator, instead of 2,730 cc less from a stock 90-94 (or more accurately 90-99 single core) NA radiator.

mellow65 · Post by **mellow65** » Mon Sep 01, 2008 10:07 pm

SemperGuard wrote:96 and 97 2.5GT and Outback radiators are what you want. Same endtanks as all non-turbo 90-99 Legacy/Outback, but with a dual core. I never got a chance to test this at the track, because I haven't driven the car in about a year, but this is what you need. Replace the fan motors with 91-94 turbo ones and add the upper radiator shroud from a 90 for extra assurance. You end up with about 550 cc less cooling capacity than a stock 91-94 radiator, instead of 2,730 cc less from a stock 90-94 (or more accurately 90-99 single core) NA radiator.

well i'll keep my eyes open for one.

were the turbo fans bigger/better then the NA ones?

BXSS · Post by **BXSS** » Tue Sep 02, 2008 2:14 am

Are the fans being turned on as they are stock on the rally car (ECU turns on-? @ 19x*), or are they being turned on via a switch or after-market fan controller?

You may want to try an after-market temp sensor / relay to turn the fan on if you are not currently doing so.
I have one of these on my Corolla & turn on + turn off temps are adjustable.

The dual core radiator is a good idea, but will not help much if the fans are off & speeds are not high.

? installing a air-air oil cooler to help keep engine temps down.....

mellow65 · Post by **mellow65** » Tue Sep 02, 2008 2:35 am

BXSS wrote:Are the fans being turned on as they are stock on the rally car (ECU turns on-? @ 19x*), or are they being turned on via a switch or after-market fan controller?

You may want to try an after-market temp sensor / relay to turn the fan on if you are not currently doing so.
I have one of these on my Corolla & turn on + turn off temps are adjustable.

The dual core radiator is a good idea, but will not help much if the fans are off & speeds are not high.

? installing a air-air oil cooler to help keep engine temps down.....

i have one hooked up to a switch and ecu has the other one. what do you think the speeds are you talking about. It's not all slow stuff, there are some fast stretches that would be faster then a fan would move.

i have the stock subaru oil cooler. from all my reading of oil coolers, the subaru one really isn't that bad. aparently you can over cool your oil with an air one with out a temp controlled restrictor. and a really nice oil cooler set of is out of the budget right now.

93forestpearl · Post by **93forestpearl** » Tue Sep 02, 2008 2:44 am

This hood vent helped immensely. It leveled off the fluctuations almost completely. It lets the high pressure air under the hood out, and if you put it right above the gap between the radiator and the motor, its very effective.

After shipping from Taiwan, it was $90.

mellow65 · Post by **mellow65** » Tue Sep 02, 2008 5:56 am

93forestpearl wrote:This hood vent helped immensely. It leveled off the fluctuations almost completely. It lets the high pressure air under the hood out, and if you put it right above the gap between the radiator and the motor, its very effective.

After shipping from Taiwan, it was $90.

i'm going to go with the even cheaper way of doing this, raise the back of the hood. maybe not as good as a big hole in the hood, but i'm sure it will help a bit.

douglas vincent · Post by **douglas vincent** » Tue Sep 02, 2008 6:28 am

Raked Hood FTMFW!

BXSS · Post by **BXSS** » Tue Sep 02, 2008 12:45 pm

+1 on raked hood or a vent (vent is super nice).

Get a few washers & longer hood bolts to get it done.
They tested this on the 4ag Corolla club & cooling improved.

But Dan tested the vent & cooling improved......

Post by **Legacy777** » Wed Sep 03, 2008 6:18 pm

SemperGuard wrote:
Legacy777 wrote:What I'd love to find is a radiator that is a wider core but still same overall dimensions....but I'm not sure if something like that exists.
96 and 97 2.5GT and Outback radiators are what you want. Same endtanks as all non-turbo 90-99 Legacy/Outback, but with a dual core. I never got a chance to test this at the track, because I haven't driven the car in about a year, but this is what you need. Replace the fan motors with 91-94 turbo ones and add the upper radiator shroud from a 90 for extra assurance. You end up with about 550 cc less cooling capacity than a stock 91-94 radiator, instead of 2,730 cc less from a stock 90-94 (or more accurately 90-99 single core) NA radiator.

Thanks for the info SemperGuard!! I'll definitely be checking that out.

Yeah I think you're right about the fan motors, they're a little beefier. But they do have to be mated to the n/a fans as the turbo fan housing would be taller.

I've already got that shroud since my car was a 1990 MY. I figured all the first gen legacies had that shroud....

Cool....well I'll have to start looking for some parts

Post by **Legacy777** » Wed Sep 03, 2008 6:19 pm

douglas vincent wrote:Raked Hood FTMFW!

Did we get carried away with the post button? I think I deleted 4 or 5 of the same posts

mellow65 · Post by **mellow65** » Fri Sep 05, 2008 8:13 am

SemperGuard wrote:96 and 97 2.5GT and Outback radiators are what you want. Same endtanks as all non-turbo 90-99 Legacy/Outback, but with a dual core. I never got a chance to test this at the track, because I haven't driven the car in about a year, but this is what you need. Replace the fan motors with 91-94 turbo ones and add the upper radiator shroud from a 90 for extra assurance. You end up with about 550 cc less cooling capacity than a stock 91-94 radiator, instead of 2,730 cc less from a stock 90-94 (or more accurately 90-99 single core) NA radiator.

so doing some checking around and doing some measuring on what i have now. my radiator is around 5-6/10 of an inch. not very big. If you want you can get just an after market one from most part stores that is 1" thick but are made from brass and are kind of spendy. if we go with the thought that the outback radiator will fit you can get that same 1" thick but in aluminum for about $160 at schucks. not a bad upgrade for the money. it is still a single core, but thicker core is at least a little better.

i haven't yet found an outback radiator in the used world. if i don't find one i might give the aluminum one a shot and see how that fits.

Post by **Legacy777** » Fri Sep 05, 2008 6:38 pm

Yeah let us know what you find out. I'd like to try and find a used radiator to test fit before I buy a new one.

I need to check my parts catalog and see what parts cross-reference.

mellow65 · Post by **mellow65** » Sat Sep 06, 2008 1:29 am

Legacy777 wrote:Yeah let us know what you find out. I'd like to try and find a used radiator to test fit before I buy a new one.

I need to check my parts catalog and see what parts cross-reference.

i always figure i can return it if it doesn't work.

i just got off the phone with a local radiator shop and they said they could build me a duel core one and possible using the stock brass end caps from my auto radiator for around $450, and around $600 if they had to build end caps too. but he said it would out cool an aluminum radiator.

that's big money to throw at my car. i think i will still keep my eyes out for a outback one or bite the bullet and just buy the new one from shucks

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upgrading cooling system for NA legacy

upgrading cooling system for NA legacy