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long travel Outbacks or making Subarus faster and more reliable offroad


pontoontodd
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  • 2 weeks later...

you da real MVP! Thanks mate! How did you like those tires? Doesn't look like you're running them anymore?

 

Still running the Hankooks on the Outback, they seem to work well.  I think you actually want some wheelspin in a lot of offroad situations with stock gearing and power levels.  An aggressive tire can actually keep you from getting up a hill or bog you down too much in a soft section.  I think I'd try Cooper Discoverer ATs based on this article:

http://expeditionportal.com/where-the-rubber-meets-the-road/

 

They probably look different because I went to the more common black steel wheels after the Forester steel wheels bent.  Right now I'm running alloys which are about 15# lighter and seem to hold up fine.

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We finished mocking up the rear suspension over the weekend.  Main goals were increased travel, more tire clearance, and getting rid of the struts.  Also, we wanted this to be bolt on and use as many stock components as possible.

 

This is all just roughly laid out for checking geometry and clearance.  The brackets will all be boxed and gusseted.


Side view of rear suspension at full bump, ride height, and full droop.
Trailing arm frame bracket replaced, two trailing links reduce spindle rotation compared to one Y shaped trailing link.
Probably make all of the rear links out of CNC bent 1.25 x .120 4130.
Links bent inward to provide more than stock tire clearance.

DSCF2037s.jpg

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DSCF2050s.jpg

 

Rear view of rear suspension at ride height and full droop.
Droop limited by inner CV bottoming out.  More droop possible by increasing camber change but more camber change increases clearance issues at full bump.

DSCF2048s.jpgDSCF2052s.jpg

View of rear suspension looking outward at full bump.
Upper link contacts frame in several spots, upper link contacts axle, axle nearly contacts frame.
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Tire barely clears shock body at full bump.  Oversized tire with 1/4" wheel spacer.  Should be able to have spring collar above tire if shock mounted "upside down."
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Tire rubs wheel well at full bump.  Oversized tire with 1/4" wheel spacer.  Might be able to hammer adequate clearance in body.
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Full bump and full droop with stock sized tire.  11.5" of travel.  Some toe out at full bump.
DSCF2086s.jpg

DSCF2087s.jpg

 

Almost done with the front, I'll post that up soon.

 

Suggestions?

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  • 2 weeks later...

After trying the five link setup and a single Y shaped trailing link, it seems it would be simplest to just make an inverted strut for the rear.  The reduced camber change solves some clearance problems and it should be overall easier and cheaper to make than the other options we tried.  Since the stock rear struts are so long it looks like we can still get 11" of travel.

 

Mockup picture to test clearances/binding:

 

DSCF2158s.jpg

 

CAD model using a 2" smooth body reservoir shock below.  Upper spring perch not shown.  Also we'll probably use a stud mount on top.

 

7261%20ASM.JPG

 

Still planning on a-arms and coilover shocks in the front, pictures of that coming soon.

Edited by pontoontodd
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Front lower arm mocked up about 1/2" farther outboard and 1 1/2" forward of stock balljoint.  This helps tire clearance with the upper arm and wheel well and the axle can extend enough and still have some travel left.  Also gives us about 10 degrees of caster.  Going to make lower arms out of laser cut 1/8" plate, box construction.

 

DSCF2105s.jpg

 

After a lot of trial and error we've arrived at this upper arm mockup.  Everything will be fully boxed and gusseted, this was just to figure out wheel, tire, and spindle clearance.  The outer part of the arm will be made out of 1/2" plate, most of the rest will be 1/8" plate.

 

DSCF2160s.jpg

 

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12" travel with full steering with some rubbing at full bump and steer.  Some hammering of the wheel wells should fix most of the rubbing.  Bump travel limited by tire rubbing in wheel well and axle hitting our upper arm rod end.  Droop travel limited by both ends of the tie rod binding.

 

DSCF2020s.jpg

 

DSCF2021s.jpg

 

Plan on using 2" coilover reservoir shocks with 6" travel.

 

Any suggestions?

Edited by pontoontodd
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JEBUS!!!  This is gonna be awsome!  DEFINATELY gonna need the D/r.  That or loose the 3rd pedal :blink: .  28" Tires with an EL headered EJ25 does not climb anything in low RPS.  That is the ONE thing lacking in my Outback and I don't have the funds to get one shipped from Down Under and want to keep the AWD aspect so no EA82 5spd swap either.

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do you have rubbing issues with fender liners with your hankooks? I threw the same set on my car with a lift and my fronts rub against the fender liners when I turn. Ripped the splash guards out and still having a miserable time :(

 

ps those arms look insane. talented fabrication we have going on here!

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do you have rubbing issues with fender liners with your hankooks? I threw the same set on my car with a lift and my fronts rub against the fender liners when I turn. Ripped the splash guards out and still having a miserable time :(

 

ps those arms look insane. talented fabrication we have going on here!

 

Yes, even with a 1.5" lift they rub the fenderwells near the footwell area bad.  And that part of the body is pretty solid so it's tough to just hammer it back.  You should also hammer flat the rib in front of the struts that the splash guard mounts to.  One of the things we'll accomplish with this suspension is moving the front wheels forward and out enough to prevent them from rubbing in the rear of the wheelwell.  Maybe still a little in the front of the wheelwell at full bump and steering.

Thanks for the compliment.  Might be able to drive it in a few days.

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wow, finally some real tech. You should put those rear coilover mounts into double shear at the bottom. Still going to come into axle flex problems under power at  full droop. looks good!

cheers

 

Thanks.  We're doing inverted struts in the rear now and everything is in double shear.  Most of these pix were just mockup, checking clearances, bump steer, etc.

 

I am nervous about the CV life, but I guess we'll find out.  Should sit about the same at ride height but obviously flexes more.

Edited by pontoontodd
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Rear inverted strut construction

 

Had to ID grind the initial springs to fit over the strut body.  The springs we're using now fit without grinding.

 

DSCF2182s.jpg

 

DSCF2184s.jpg

 

Had to clearance the wheelwell for the strut body, shifted it away from the spindle for tire clearance, and it swings in at full droop, so first I notched the bottom of the "frame rail":

 

DSCF2190s.jpg

 

hammered the crap out of it and welded it back together:

 

DSCF2220s.jpg

 

Strut body with camber adjustment:

 

DSCF2216s.jpg

 

Long travel (11" at the strut) vs stock (8"):

 

DSCF2218s.jpg

 

Installed:

 

DSCF2223s.jpg

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Great work!  I'll be very interested to see how that front upper a-arm works out.  Also did I mention how excited I am for a new video/set of offroad photos!

After this set of modifications, what's next?  Underbody protection (aluminum/uhmw)?  Imported EJ dual range?

Keep up the fab/tech!

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Great work!  I'll be very interested to see how that front upper a-arm works out.  Also did I mention how excited I am for a new video/set of offroad photos!

 

After this set of modifications, what's next?  Underbody protection (aluminum/uhmw)?  Imported EJ dual range?

 

Keep up the fab/tech!

 

Glad you like it.  The upper arms are a little questionable but there is a lot of 1/2" steel plate in them and they seem to be holding up well so far.  The upper arm mounts need to be reinforced a bit though.  It would have been much simpler to go with long travel struts in the front but I don't think we could have gotten 12" of wheel travel that way.

 

I really want to get some good video of this in action but unfortunately it will be a few weeks.

 

UHMW on the belly is a good idea.  I don't really have much interest in crawling though, or many places where it's needed within 500 miles of here, so probably no dual range.  I have lot of other ideas, but an M62 supercharger is pretty high on the list.  I've seen a few clean installs with a TMIC.

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  • 2 weeks later...

Drove the car a few times now and it's already much better than before.  It can use some tuning, especially in the front, and there are a few minor issues to work out, but overall I'm happy with it.  Probably be a few weeks before I can get good video up.

 

Holy ballz of a build!  What trans/rear end combo are you currently running?

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