long travel Outbacks or making Subarus faster and more reliable offroad

[Uberoo]

It looks like you have plenty of surface area for the radiator, but with how well you have the bottom of the engine bay sealed up there is not alot of airflow through the engine bay.Cut some vents in the hood between the radiator and the tires and it should improve airflow and thus cooling.Also if possible remove the factory scoop because it is pressurizing the engine bay and compounding your overheating problem.Look on google for heat extraction hoods to get ideas,you might want to try it with another hood.

 

The biggest radiator in the world wont cool if there isn't a pressure differential between the the sides of it.Say for the sake of argument that when stock that there was 1 psi on the front of the radiator, and .45 psi in the engine bay, there is .55 psi of airflow through the radiator at speed.Now lets say, with your extensive skidplate under the engine lets say the underhood pressure is now .7 psi, or only .3 psi worth of airflow.That reduction in airflow through the radiator would make your radiator behave like it was 54% smaller-overheating.

[pontoontodd]

It looks like you have plenty of surface area for the radiator, but with how well you have the bottom of the engine bay sealed up there is not alot of airflow through the engine bay.Cut some vents in the hood between the radiator and the tires and it should improve airflow and thus cooling.Also if possible remove the factory scoop because it is pressurizing the engine bay and compounding your overheating problem.Look on google for heat extraction hoods to get ideas,you might want to try it with another hood.

 

The biggest radiator in the world wont cool if there isn't a pressure differential between the the sides of it.Say for the sake of argument that when stock that there was 1 psi on the front of the radiator, and .45 psi in the engine bay, there is .55 psi of airflow through the radiator at speed.Now lets say, with your extensive skidplate under the engine lets say the underhood pressure is now .7 psi, or only .3 psi worth of airflow.That reduction in airflow through the radiator would make your radiator behave like it was 54% smaller-overheating.

 

I like this idea, thanks.  Going to start thinking about the best way to do it.

 

I also plan on replacing the radiator and condenser, they're both pretty beat and have some sand jammed in the fins.  I'll probably drill some holes in the thermostat while the coolant is out, might go mostly water at that point too.  My other thought is to put a big heater core in the back somewhere with a fan.  Need to see what temperatures the temp gauge is indicating at halfway, 3/4, etc.

[Uberoo]

Try venting the hood first and go from there.

 

something like this would be effective

Edited April 9, 2016 by Uberoo

[idosubaru]

If start another thread on maintenance issues.

 

Stalling is often the idle control valve. Clean or swap in a used one.

 

Did the cam and crank sensor codes go away?

 

Is it still arcing?

What brand wires?

Replace plugs.

 

Those engines aren't very forgiving with plugs and wires. OEM NGK is best or high quality.

[pontoontodd]

Try venting the hood first and go from there.

 

I definitely want to try that.  So far I think the easiest way would be to get a Legacy hood (no scoop) and put a GT500 vent on it.  Sounds like they're $50 at the Ford dealer.

 

 

I think we need a big improvement in cooling to be safe though.  This was a 60 or 70 degree day and the temps crept above the middle with the AC off a few times.  Cruising down the highway a few days later with temps in the 80s we had to run the heat to keep it under control.  I'm sure it will be over 100F in Nevada in August and it would make for a much easier day if we could run the AC.  I think some sort of additional heat exchanger in the back, new radiator/condenser, higher % of water in the coolant, and drilling holes in the thermostat should all help.  The other issue is that living in northern IL we won't be able to test any of this for a while.  I would like to have it to the point where I can drive in stop and go traffic in the 80s and block off the radiator with cardboard and not have the car overheat.  If part of our problem is that the radiator gets dented and clogged from rocks, sand, and dust, that is guaranteed to happen during a 600+ mile off road race so we need a good margin of safety.  We'll see what happened to the shock soon but I think overheating is most likely to take us out of the race based on what we've seen so far.

[idosubaru]

Nice work and play! Well done all around. Way to show a bunch of weak points and repairs/upgrades.

 

Youre aware of EJ25 headgasket issues im sure? Rod bearings aren't terribly forgiving in those either. Getting that cooling under control sounds like a good move.

[pontoontodd]

Nice work and play! Well done all around. Way to show a bunch of weak points and repairs/upgrades.

 

Youre aware of EJ25 headgasket issues im sure? Rod bearings aren't terribly forgiving in those either. Getting that cooling under control sounds like a good move.

 

Thanks.

Yes, the previous owner supposedly replaced the head gaskets.  Recently saw a blown EJ in our friend's shop and I was shocked how tiny the bearings are on these engines.

[Uberoo]

In addition to venting the hood pull the radiator and clean out the fins.Spray from the inside out.Back flush the radiator and cooling system with the garden hose while your at it.Even if you've been spraying it out inside the car their is no comparison to the amount of filth you can get out once the radiator is out of the car.

[pontoontodd]

In addition to venting the hood pull the radiator and clean out the fins.Spray from the inside out.Back flush the radiator and cooling system with the garden hose while your at it.Even if you've been spraying it out inside the car their is no comparison to the amount of filth you can get out once the radiator is out of the car.

 

For $150 I can get a new radiator (Denso) and condenser shipped to my house so I'll probably do that.  The condenser is far from flat and has a lot of bent fins.  The radiator probably isn't as bad.  I will probably blast out the old ones at that point to see how much comes out of them, they'll make good spares at least.  Maybe I'll wait until it's a little closer to V2R so I don't just get the new ones packed with dirt in the meantime.  That will give us time to test some other cooling mods.

[Uberoo]

Don't use pressure washer to clean out the radiator because you will just bend the fins. Use a garden hose. You want volume rather than pressure.

[Cyfun]

What is different about it?

 

Stock 99 Outie radiator is supposedly about 26.5 inch wide by 14.5 inch tall and only 5/8 inch thick.  Whereas the H6 radiator is about 27.5 inches wide by 13.75 inches tall and is 1 inch thick.  That's 240 cubic inches vs 378 cubic inches of volume. However, I think the inlet hose size is slightly smaller on the H6 one.  Might have to experiment with hoses, too.

 

I don't recall if your car is a stick or auto, but if it's an auto, you may consider unhooking the rad's trans cooler lines and running them through a completely separate trans cooler.

[pontoontodd]

Stock 99 Outie radiator is supposedly about 26.5 inch wide by 14.5 inch tall and only 5/8 inch thick.  Whereas the H6 radiator is about 27.5 inches wide by 13.75 inches tall and is 1 inch thick.  That's 240 cubic inches vs 378 cubic inches of volume. However, I think the inlet hose size is slightly smaller on the H6 one.  Might have to experiment with hoses, too.

 

I don't recall if your car is a stick or auto, but if it's an auto, you may consider unhooking the rad's trans cooler lines and running them through a completely separate trans cooler.

 

Thanks for the answer on the H6 radiator size.  Sounds like it'd be worth getting one and trying to make it fit and hook up.  It does look like it has two inlets, one could probably just be capped.  Where did you get that info?  That would be handy if the same source has size information for heater cores (or tiny radiators).  I am thinking about putting one in the hatch door.  Move the license plate to one side and fit about an 8" square heater core in the door, probably with an 8" electric fan on the back of the door.  Should be an excellent low pressure zone to pull air out at speed too.

 

It's a manual trans.

[Uberoo]

Thanks for the answer on the H6 radiator size.  Sounds like it'd be worth getting one and trying to make it fit and hook up.  It does look like it has two inlets, one could probably just be capped.  Where did you get that info?  That would be handy if the same source has size information for heater cores (or tiny radiators).  I am thinking about putting one in the hatch door.  Move the license plate to one side and fit about an 8" square heater core in the door, probably with an 8" electric fan on the back of the door.  Should be an excellent low pressure zone to pull air out at speed too.

 

It's a manual trans.

K.I.S.S.Clean out the radiator or install a bigger one and vent the hood if need be.Don't install a heater core or radiator in the back because that is ALOT of extra complexity for very little gain.In mud the radiator can be relocated to the back so it doesn't fill with mud, but even then unless alot of thought is put into the design they still run a little warm at highway speeds.Not to mention getting the air out of a rear mounted anything is a major PITA.

[pcjnw30]

You can purchase a mishimoto all aluminium radiator for around $250 for legacy, they also sell a dual electric fan & shroud kit for another $100 or so.

I have one mounted horizontally between the strut tower with a cowl induction hood on my 86 wagon with ej 2.2 conversion. It's been working well ... so far.

[pontoontodd]

K.I.S.S.Clean out the radiator or install a bigger one and vent the hood if need be.Don't install a heater core or radiator in the back because that is ALOT of extra complexity for very little gain.In mud the radiator can be relocated to the back so it doesn't fill with mud, but even then unless alot of thought is put into the design they still run a little warm at highway speeds.Not to mention getting the air out of a rear mounted anything is a major PITA.

 

I would agree but we probably won't have a lot of chances to do hot weather testing before V2R.  Worst case with the rear mounted heater core, if it leaks we put the lines back and add water.  Considering we were running a little hot in 70F weather in the race and very hot in 80F weather on the highway we need as much additional cooling as we can get.  Also, if a thicker/cleaner radiator, hood vents, etc help at first, how likely is it that will get clogged again by the end of the longest desert race in the US?

[pontoontodd]

You can purchase a mishimoto all aluminium radiator for around $250 for legacy, they also sell a dual electric fan & shroud kit for another $100 or so.

I have one mounted horizontally between the strut tower with a cowl induction hood on my 86 wagon with ej 2.2 conversion. It's been working well ... so far.

 

Do you know of one specifically for 99 Legacy?  I've seen them for first gen and third gen legacy but not second gen.  I've seen a few others that might fit too, but it would be nice if it dropped in.

[Uberoo]

I would agree but we probably won't have a lot of chances to do hot weather testing before V2R.  Worst case with the rear mounted heater core, if it leaks we put the lines back and add water.  Considering we were running a little hot in 70F weather in the race and very hot in 80F weather on the highway we need as much additional cooling as we can get.  Also, if a thicker/cleaner radiator, hood vents, etc help at first, how likely is it that will get clogged again by the end of the longest desert race in the US?

Run straight water with some water-wetter or similar with corrosion inhibitors.Or at the very least run only 10% antifreeze.Run a higher pressure radiator cap, but less than 20 PSI.Gut your thermostat or run a washer with the same internal diameter.Make sure your fan shrouding is working correctly, and seal off ANY gaps between the radiator and the car.Run corroplast ducting in front of the radiator to force even more air through the radiator.Make sure your skidplate isn't scooping dirt and debris into the radiator.

[Cyfun]

Thanks for the answer on the H6 radiator size. Sounds like it'd be worth getting one and trying to make it fit and hook up. It does look like it has two inlets, one could probably just be capped. Where did you get that info? That would be handy if the same source has size information for heater cores (or tiny radiators). I am thinking about putting one in the hatch door. Move the license plate to one side and fit about an 8" square heater core in the door, probably with an 8" electric fan on the back of the door. Should be an excellent low pressure zone to pull air out at speed too.

 

It's a manual trans.

I just looked up parts for various models on the O'Reilly Auto website. They give lots of detailed specs.

 

Uberoo is probably right, though, an aluminum racing radiator is a good bet, and they're often about the same price as stock. A little googling found a thread on this exact subject: http://www.subaruoutback.org/forums/110-gen-2-2000-2004/111962-h-6-radiator-upgrade-will-legacy-radiator-fit-outback-both-02-04-a-5.html

 

I honestly still think there's another reason you keep heating up, though. Either the t-stat is stuck or you've got a leak somewhere.

 

Might also check out WRX radiators. You'd think a turbo car would offer substantial cooling.

Edited April 15, 2016 by Cyfun

[pontoontodd]

I just looked up parts for various models on the O'Reilly Auto website. They give lots of detailed specs.

 

Uberoo is probably right, though, an aluminum racing radiator is a good bet, and they're often about the same price as stock. A little googling found a thread on this exact subject: http://www.subaruoutback.org/forums/110-gen-2-2000-2004/111962-h-6-radiator-upgrade-will-legacy-radiator-fit-outback-both-02-04-a-5.html

 

I honestly still think there's another reason you keep heating up, though. Either the t-stat is stuck or you've got a leak somewhere.

 

Might also check out WRX radiators. You'd think a turbo car would offer substantial cooling.

 

Thanks for the Oreilly tip, they do have dimensions on all the radiators and heater cores.

 

I'm trying to avoid a lot of work fitting some kind of non stock radiator and fans but maybe I'll have to do that.  I just went through all the radiators on Summit with drivers side lower outlet and passenger side upper inlet and they're all too tall.

 

I will see if I can get one of those head gasket leak testers.  Replaced the t-stat with one from the Subaru dealer not long ago.  I agree with you guys that something is probably wrong, clogged radiator, stuck thermostat, etc since turning on the heat cools it right down.

 

2005 STI radiator looks about the same as the 2002 H6, about the right size but top and bottom tanks so that might be some work getting one of those to fit too.

 

Other than the overheating I'm really happy with how the car held up.  There was barely any dust in the air filter, brake pads still look new, only one bushing in the suspension seems sloppy, wheel bearings seem good, etc.

[pontoontodd]

Run straight water with some water-wetter or similar with corrosion inhibitors.Or at the very least run only 10% antifreeze.Run a higher pressure radiator cap, but less than 20 PSI.Gut your thermostat or run a washer with the same internal diameter.Make sure your fan shrouding is working correctly, and seal off ANY gaps between the radiator and the car.Run corroplast ducting in front of the radiator to force even more air through the radiator.Make sure your skidplate isn't scooping dirt and debris into the radiator.

 

Planning on water w/ water wetter or a little anti freeze.  Going to drill some small holes in the thermostat.  As posted we've built as much of an air dam to force air into the radiator as we can.  It's possible that's scooping crap into the radiator but the front of it looks fairly clean.

[pontoontodd]

Here are a couple of pictures from the race:

 

 

 

The race was a lot of fun and I'm still amazed how well we did against the competition.  We finished third in our class of nine trucks because there were only three of us that finished both races.  There were only three trucks in the class that were faster than us though, the rest were running similar or slower lap times.  Perhaps more amazing, only nine of the 29 total entries finished both races.  So just finishing was an accomplishment.  We have definitely driven over much rougher terrain and we've driven that fast and jumped the car before, but never all day long like this.  We definitely had to push the car harder than we would trail riding in order to finish in the time limit.  It was probably a few feet off the ground thirty times that day.  We might have to go back down there sometime.

[pontoontodd]

This is the strut with the bad hose that was bottoming out.  The other rear strut is slightly bent but not as bad.

 

 

In this picture you can see the weld was starting to crack too:

 

 

I am going to shorten up the mounting tabs like I did on the front struts.  There is room between the strut and the sidewall now that the spring is above the tire.  It also helps that these need a little more positive camber which will give us a little tire/strut clearance.  I'll also gusset the bottom of the tabs.  Trying to find different springs so I can move the spring perch up while I've got it all cut up.  Anyone know of a company that makes inexpensive custom coil springs?

[Cyfun]

Thanks for the Oreilly tip, they do have dimensions on all the radiators and heater cores.

 

I'm trying to avoid a lot of work fitting some kind of non stock radiator and fans but maybe I'll have to do that.  I just went through all the radiators on Summit with drivers side lower outlet and passenger side upper inlet and they're all too tall.

 

I will see if I can get one of those head gasket leak testers.  Replaced the t-stat with one from the Subaru dealer not long ago.  I agree with you guys that something is probably wrong, clogged radiator, stuck thermostat, etc since turning on the heat cools it right down.

 

2005 STI radiator looks about the same as the 2002 H6, about the right size but top and bottom tanks so that might be some work getting one of those to fit too.

 

Other than the overheating I'm really happy with how the car held up.  There was barely any dust in the air filter, brake pads still look new, only one bushing in the suspension seems sloppy, wheel bearings seem good, etc.

 

You might also just flush the spoob out of the system.  I've had good luck with water and wood bleach.  But that head gasket tester would be the place to start.

[pontoontodd]

You might also just flush the spoob out of the system.  I've had good luck with water and wood bleach.  But that head gasket tester would be the place to start.

 

Stopped at the local Advance yesterday and they had no idea what I was talking about with the head gasket tester.  I'll look around a little more.  I looked them up online so at least I know what you're talking about now.

 

We got the HVAC fan out of the Outback since it was making noise occasionally after the race, especially when turned all the way up.  There were some sticks and rocks in it:

 

 

Couldn't get any pictures but the plastic box the fan blows into that holds the evaporator had an inch or two of dirt and debris in the bottom.  The evaporator was partially covered with about 1/4" of mud too, so we cleaned it out as best we could.  Should improve AC performance.

[Cyfun]

I avoid Vatozone like the plague, as they seem the least competent of the parts jockeys.  Oreillys tends to have a better selection of loaner tools, and I know for a fact they have those headgasket testers.  Otherwise, you can always buy the kit, it's like $30 online.