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pontoontodd

long travel Outbacks or making Subarus faster and more reliable offroad

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The recent cold temperatures (-30F/-20C) here have been a good test of my Subaru fleet's batteries.

The Harbor Freight lithium jump starter has been worth its weight in gold, I think it's Vulcan brand.  I have an older one from a different brand that doesn't always work anymore.

The battery in my Impreza I got from a junkyard cranks slow as always, had to use the jump starter on it once or twice.

The Odyssey (PC1230-75/86 760CCA) in my 1999 Outback would only hold a charge for a day, if I drove it every day it was usually fine but if it sat for a few days it wouldn't start.  Unfortunately it's just past the four year warranty.  That battery has been through a lot of vibration and heat and has been discharged many times.  I decided to try a Duracell Ultra Platinum AGM with dual terminals (sli75dtagm 640CCA) from Batteries Plus since it's cheaper and so far it's been great, can sit for days and start right up.  I think the terminals might be too far away for stock battery cables but I like the dual terminals, we've had the top post clamps come off/loose during desert races, having the cables also bolted to the side posts adds redundancy.

I got an Oreilly super start platinum AGM (640CCA) for my 2002 Outback about two years ago and it works great.  The last time I bought one I had to specifically ask them to look it up, apparently it doesn't come up as best fit for that car but it fits fine.

Before I bought my 2001 Outback they put in a new Les Schwab battery (500CCA) about a year ago.  In the past month or so it's started slow a few times and had to be jump started once or twice.  It has a 60 month warranty but there's not a Les Schwab anywhere near here so I got another Oreilly AGM and it's been good.

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Nice videos !

Would you make any of your coilovers, how you build them inside and out, what parts you used, spring rates and the stroke you get out of them. Would love to see all the engineering involved for the fabrication.

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1 hour ago, jf1sf5 said:

Nice videos !

Would you make any of your coilovers, how you build them inside and out, what parts you used, spring rates and the stroke you get out of them. Would love to see all the engineering involved for the fabrication.

Glad you like the videos.  Hope to get some bigger jumps on video this spring.

I don't completely understand your question about the struts.  I'm not going to give out detailed plans on how to make them since I'm sort of trying to sell them.  The fronts have 9" of stroke which gives 10" of wheel travel, the rears have 11" of stroke which gives 12" of wheel travel.  Sorry if this comes across as rude, but if you have the ability to make them you probably don't need plans and could just go by all the pictures I've posted.  There aren't many complicated machined parts but there are quite a few custom machined parts you'd at least need a lathe to make and I had ten springs custom wound for the front struts.  If you look through page 25 of the thread that should give you a good idea of all the parts that go into the current design.  On page 4 I posted a CAD drawing of the original inverted strut design, same basic design we're still using.

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Crazy cold temps up that way followed by a warm front and more grey: gotta love the Midwest winters, back and forth with plenty of moisture! Not really any sun in the last couple months, either. Always look forward to hints of spring right about now...

45 pages here, and I have only skimmed some of it. Fab work and motivation is impressive, let alone that fact that you drive the sh*t out of what you build!

K

 

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21 hours ago, pontoontodd said:

I don't completely understand your question about the struts.  I'm not going to give out detailed plans on how to make them since I'm sort of trying to sell them.  The fronts have 9" of stroke which gives 10" of wheel travel, the rears have 11" of stroke which gives 12" of wheel travel.  Sorry if this comes across as rude, but if you have the ability to make them you probably don't need plans and could just go by all the pictures I've posted.  There aren't many complicated machined parts but there are quite a few custom machined parts you'd at least need a lathe to make and I had ten springs custom wound for the front struts.  If you look through page 25 of the thread that should give you a good idea of all the parts that go into the current design.  On page 4 I posted a CAD drawing of the original inverted strut design, same basic design we're still using.

I understand that you won't give more details about your struts as you are trying to sell them. I was just curious as I had Proflex Evo 2 inverted struts that didn't work as smooth as yours by the looks in the videos, and it was nothing to do with spring rate and/or hydraulic setup, only stick-slip due to bad bearing (though PTFE) and lubrication of the bearings. I think that they were not designed to be Mc Pherson type struts from the begining. I finally sold them cheap....

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14 minutes ago, jf1sf5 said:

I understand that you won't give more details about your struts as you are trying to sell them. I was just curious as I had Proflex Evo 2 inverted struts that didn't work as smooth as yours by the looks in the videos, and it was nothing to do with spring rate and/or hydraulic setup, only stick-slip due to bad bearing (though PTFE) and lubrication of the bearings. I think that they were not designed to be Mc Pherson type struts from the begining. I finally sold them cheap....

Were the springs inline with the sliding part of the strut or angled out at the bottom towards the tire?  That makes a difference in theory and in practice.  We have tried a few different kinds of bushings to find something we're happy with, the first few kinds tended to shrink when soaked in grease for a while.  ID ground the last few sets of housings we made, that definitely helped, or at least vastly reduced the amount of hand sanding needed to make the bushings fit right.  Also put grease fittings in between the bushings and we'll usually grease them all after a long weekend of riding, probably not necessary, annually would probably be enough.  I have read one of the big problems with the STI inverted struts is that the grease dries out or washes out after a while, people add grease fittings to those.

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The springs were inline just like most coilovers. I'm sure it does help to have them angled but I still think that the problem came from the wrong lubricant. I now run the non-inverted HotBits coilovers since '14, Back then, I also feeled that they were not as smooth as OEM struts even with softer spring rates so I decided to test different oils, ATF Dexron III being the oil used by HotBits. I first tried Citroën LHM, a little better but not good enough, then I tried Motorex 10W fork oil, and suddenly the stick-slip effect was gone but the damping was too firm so I changed for Motorex 2,5W....and now I have a flying carpet ! So from my experience, the right oil is the most important when it comes to shock absorbers.

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4 hours ago, jf1sf5 said:

The springs were inline just like most coilovers. I'm sure it does help to have them angled but I still think that the problem came from the wrong lubricant. I now run the non-inverted HotBits coilovers since '14, Back then, I also feeled that they were not as smooth as OEM struts even with softer spring rates so I decided to test different oils, ATF Dexron III being the oil used by HotBits. I first tried Citroën LHM, a little better but not good enough, then I tried Motorex 10W fork oil, and suddenly the stick-slip effect was gone but the damping was too firm so I changed for Motorex 2,5W....and now I have a flying carpet ! So from my experience, the right oil is the most important when it comes to shock absorbers.

The viscosity of shock oil is certainly important.  Also keep in mind that the "weight" system is almost meaningless.  One brand's 10W might be thicker than another brand's 15W, etc.  There are some charts online showing many different brands of shock oil and their viscosity at high and low temperatures.  I've thought about changing out the oil in standard struts with something thicker for more damping but we've blown out the seals as it is, that would just happen more often with a thicker oil.

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Very true about the viscosity of the different oil brands. The official measures are done at 40°C and 100°C and are measured in cSt (1 centi-stoke = 1mm2/s). Another way to modify the dampening is to change the hydraulic settings (shims) but thats a longer work. The easiest way is to change the nitrogen pressure, its not as accurate but it still helps finding the right settings.

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4 hours ago, jf1sf5 said:

Very true about the viscosity of the different oil brands. The official measures are done at 40°C and 100°C and are measured in cSt (1 centi-stoke = 1mm2/s). Another way to modify the dampening is to change the hydraulic settings (shims) but thats a longer work. The easiest way is to change the nitrogen pressure, its not as accurate but it still helps finding the right settings.

I think changing shims is actually easier and cheaper than changing oil.  If you're off that much I could see only a different oil will get you close though.  You can't change the nitrogen pressure much, too little and you'll have cavitation, too much and you blow them up.

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Maybe on the Fox shocks is it easier to change the shims but on the HotBits, I would have to drain the oil too thus why I changed the viscosity of the oil instead of the shims. The recommended nitrogen pressure is around 8bar/120psi and I went up to 12bar/180psi and everything is still fine, nothing's leaking, the nitrogen in the canisters is separate from the oil with a floating piston, not a membrane, this maybe helps for more precise oil filling keeping the seals in good operating conditions.

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3 hours ago, jf1sf5 said:

Maybe on the Fox shocks is it easier to change the shims but on the HotBits, I would have to drain the oil too thus why I changed the viscosity of the oil instead of the shims. The recommended nitrogen pressure is around 8bar/120psi and I went up to 12bar/180psi and everything is still fine, nothing's leaking, the nitrogen in the canisters is separate from the oil with a floating piston, not a membrane, this maybe helps for more precise oil filling keeping the seals in good operating conditions.

The off road shocks I've worked on you don't have to drain the oil to change shims.  I've always charged all the ones I work on to 200psi, I think you can go to 250 or 300 on most.  Ours have a floating piston in the reservoir.

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Went through the rear end of the 99 Outback to fix a few issues and do some preventative maintenance.  Put aluminum reservoirs on the struts hoping they'll run a little cooler.  Changed the valving, put in new oil, and replaced a boot and the top bearings.

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I had a wheel bearing fail last year and I've been putting 20k miles a year on this car so I thought it'd be best to just replace the wheel bearings, seals, and hubs over the winter.  Will probably do this every winter if I keep driving the car that much and it keeps them from failing on the road.

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That one parking brake shoe was really bad so I replaced all of them.  I don't use it much but I think mud and sand get inside the drum and just eat the shoes.

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One CV boot was leaking, another one might have been leaking slightly, they were all at least a little cracked, and this one was worn over halfway through, so I replaced them all and repacked the CVs.

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I think I've already swapped out the trailing arm on the driver's side but this one on the passenger side was getting bad so I replaced that with a used one.  They're $76 from the dealer so I'm thinking about getting a couple of them.

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While I had everything apart I figured I should do some body repair.  It hadn't really failed completely but was starting to crack again, haven't done anything on this corner for about five years I think.  Hard to see from this picture but the seam on the left is separated and the seam at the bottom where the floor meets the strut tower is pulling apart.  Also that shiny piece laying on the floor was barely attached to the strut tower so I pulled it off and cleaned up all the rust and sealer.

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Welded those two seams and welded that extra sheet back on.  Also added a piece of sheet metal to the bottom of that seam by the door (lower left).

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Painted to slow the rust.

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This is what it looked like in the wheel well after a little cleanup.

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Welded some of the seams, then added that big patch.  You can see where I welded the extra sheet on the inside penetrating through.  Burned/scraped more undercoating off.  That big rusty crack on the right is welded on the inside of the car.  Hammered for some strut and tire clearance.

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Painted.

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I've noticed a gasoline smell when I filled up the last couple times.  Pretty sure this is the source.  I've made these gaskets a couple times now, I think originally from cork and the last time from Buna N which is supposed to stand up to gasoline and alchohol.

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They're just shredded.  I suppose some of the breakdown may be mechanical but I assume it's mainly chemical.  Whatever they made that flap out of on the inside is still holding up great.

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Got some flourosilicone from McMaster, expensive but hopefully it'll last more than a couple years.

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20 hours ago, pontoontodd said:

The off road shocks I've worked on you don't have to drain the oil to change shims.  I've always charged all the ones I work on to 200psi, I think you can go to 250 or 300 on most.  Ours have a floating piston in the reservoir.

I maybe didn't use the right word. I thought that the shims were the washers used to slow up the piston in the shocks. How do you name this part ? Valving washers ?

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Just now, jf1sf5 said:

I maybe didn't use the right word. I thought that the shims were the washers used to slow up the piston in the shocks. How do you name this part ? Valving washers ?

Yes, shims or valving washers.  Once you have the shaft out you just have to take the nut off, restack the shims, and put it all back together.

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