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Premium Member
1998 Forester S Auto
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147 Posts
Discussion Starter #1
Hey everyone, this is the new build for The Wandering Foz, continuing where the old thread left off: http://www.subaruforester.org/vbulletin/f115/great-alaskan-tundra-humper-391762/

IMG_3756 by jeremiah stewart, on Flickr

Goal:
I have wanted to race the Baja 1000 since I was a little kid, but a few years ago I came across the Mexican 1000 which is a little more grassroots and easier for a normal guy like me to race in. So that's the goal! I wanted to race in their "Rally Raid AWD" class using my Hotbits coilovers as they were at the max travel for that class, but most years there is nobody in that class. Might as well try to be competitive if i'm entering a race right? So the class I'm shooting for is Score Class 7 or BITD 7200. In the Mexican 1k it'll either be "Heavy Metal Class" or "Pre-run Truck".

For now I will only be focusing on suspension so I can stay on track to be able to take the foz on a roadtrip planned for May 2017. A roll cage and a bunch of safety items will need to be built after the roadtrip unless I have the time to do the rollcage this winter. Shooting to make the race in the spring of 2018, but if the foz is ready sooner than then, then I will enter a domestic race to get my feet wet.

Plan:
  • Dual A-arm front suspension cycling 18-22" of travel
  • Dual A-arm rear suspension with toe link (will make sense later - similar to the PPI 015 Toyota) cycling 20-24" of travel
  • 32" tires on factory offset wheels to allow for longer arms and more travel while keeping it under the BITD max width of 85"
  • Either King or Fox internal bypass coilovers all around
  • High compression EG33 unless the length is more than I want to build around, then it'll be an EZ30
  • Extended length axles (+8") probably from DSS

p.s. Some of you who have been on this forum for a while might be getting excited because you remember the first person to attempt this kind of build:
http://www.subaruforester.org/vbulletin/f115/project-forestar-2-baja-foz-161097/
 

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Premium Member
1998 Forester S Auto
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147 Posts
Discussion Starter #2

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Premium Member
1998 Forester S Auto
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147 Posts
Discussion Starter #3
Got all of my heim joints in, as well as all of the pieces that I drew on CAD and got from Anderson Design and Fab

DSC00408 by jeremiah stewart, on Flickr

DSC00411 by jeremiah stewart, on Flickr

DSC00423 by jeremiah stewart, on Flickr


Started on the front subframe, using the old subframe as a jig:


DSC00421 by jeremiah stewart, on Flickr

DSC00419 by jeremiah stewart, on Flickr

Need to start boxing it in and reinforcing it, then get it under the car to tie it into my other mounts.

Below is my crazy ball joint replacement idea, let's hope it works out. The big hole is to hold a uniball joint, which I am still waiting on. I may need to just fab a whole knuckle for more strength though, we'll see.


DSC00414 by jeremiah stewart, on Flickr

DSC00415 by jeremiah stewart, on Flickr


The upper and lower joints will be 1" uniball joints, probably overkill.
 

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Premium Member
1998 Forester S Auto
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147 Posts
Discussion Starter #9
Glad to see excitement about this :D

I made some good progress yesterday, but got cut short by having to go pickup an engine block for mockup.
So I started off by bolting the subframe in to mockup the knuckle and make sure everything was gonna work before I started boxing it in:

DSC00499 by jeremiah stewart, on Flickr

DSC00500 by jeremiah stewart, on Flickr

Measured the track width from the center of the subframe, 42.5" then moved the tire inward 2 inches to 40.5" to give me room in the future for 32x11.5 tires with an inch for wheel offset differences. This will be the stance with stock fenders:

DSC00533 by jeremiah stewart, on Flickr

Bolted the knuckle into a wheel as well:

DSC00544 by jeremiah stewart, on Flickr

DSC00545 by jeremiah stewart, on Flickr

There's about 1/2" clearance all around in a 15" wheel, pretty good. Most likely going to be running 16's anyway.

Mocked up the steering rack location:

DSC00534 by jeremiah stewart, on Flickr

Looks like the inner heims are going to stick out just past the LCA pivot after the clevis is bolted on, so I may see some bump steer, but it looks like if I play my cards right, I can mount the LCA down one hole (UP in the pic) and then the inner tie rod heim would be in-line with the LCA and UCA pivots. So either way, we should have very minimal bump steer:

DSC00535 by jeremiah stewart, on Flickr

So I cut the original mounts out of the old subframe to save time, and welded them in the new subframe, and plated them a bit:

DSC00537 by jeremiah stewart, on Flickr

DSC00538 by jeremiah stewart, on Flickr

Mounted:

DSC00539 by jeremiah stewart, on Flickr

Fits like factory (the true test will be to see if the steering shaft fits right up like it did...)

DSC00541 by jeremiah stewart, on Flickr

View from wheel well:

DSC00543 by jeremiah stewart, on Flickr

And lastly, I just need to add these gussets:

Changes by jeremiah stewart, on Flickr

I made the shape the way it is to give clearance for the exhaust and the cylinder heads, but made way more than is necessary which would cause this thing to fold up the first time i landed a jump off-kilter. So anyways, that's the progress so far! My uniball's finally shipped out, so next weekend I may have some control arms mocked up! That's the exciting bit :D
 

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Premium Member
1998 Forester S Auto
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147 Posts
Discussion Starter #10
Latest news is that the uniball joints came in, so I tacked two the cups into the knuckle i've been using for mockup:

DSC00569 by jeremiah stewart, on Flickr

But the bad thing is that the none of the local steel places have the DOM I need, and Amazon doesn't offer it via Prime anymore -lol- so it's going to be about 2.5 weeks until I have the tubing, which is when I'll be in Wyoming for Christmas. Probably should've checked that out a long time ago lol. Time to work on the wire harnesses I guess.
 

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Premium Member
1998 Forester S Auto
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147 Posts
Discussion Starter #12
Bummer on the DOM. No fabricators nearby to borrow a bit?
You know, I hadn't even considered that.. But I ordered 20ft of 1.25" which will be waiting for me to get back.

Small Update:

I got the engine over to my garage this weekend and test fit the subframe on it to start beefing it up. But first, for those that don't know anything about the engine, it's an EG33 out of a 1992 Subaru SVX. I had it bored out to 98mm (raised displacement by about .6 liters) to fit the forged 11:1CR pistons from JE Pistons. The crank and rod bearings are by King. Also, I deleted the EGR system.





Subframe bolted under it:

DSC00620 by jeremiah stewart, on Flickr

Clearances look great, I have a lot of room for strengthening, keeping in mind engine movement of course:

DSC00621 by jeremiah stewart, on Flickr

DSC00622 by jeremiah stewart, on Flickr

Upside down:

DSC00623 by jeremiah stewart, on Flickr

This shows why I shaped the subframe the way I did, for the exhaust:

DSC00624 by jeremiah stewart, on Flickr

But I don't like how low the exhaust will be since I was shooting for about 4-5" of ground clearance to the subframe at full bump. The exhaust would have like an inch like this, so i'll be building some weird headers later on.
 

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Premium Member
1998 Forester S Auto
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147 Posts
Discussion Starter #13
So i started on control arms this last weekend, but just in the nick of time before I really made anything, I came across vsusp.com and decided I might as well plug in my numbers and see what I'm working with. It appeared to be limited to about 14inches of travel due to the camber going -20 degrees at full bump, and the upper arm being too short to get enough droop travel. So apparently my initial mock up was crap lol. But I've determined that if I move the upper heims inward 1.5" (can't go further due to valve cover position) and the lower mount down 2" and outward 1.5", I get what looks to be pretty good geometry:
Camber at full droop: -2*
Camber at ride height: -2*
Camber at full bump: -10*
KPI looks good at about 14*, giving a scrub radius of .58" with 32" tires. So I didn't do too bad on the knuckles, and if I can ever get the gearing for it, going to 33" or 35" tires, the scrub radius only improves.
Actual lateral tire scrub I'm unsure about, but from ride height to bump looks very minimal.
Only other things to account for are CV's and tie rod ends, the latter of which I have a lot of freedom with on the knuckle end, and the rack end can be adjusted to put the heims inline with the upper and lower mounts. As for the axles: I'm unsure right now about how much plunge the front axles will have, but I'm planning on running factory style inner joints which have about 2" of throw, and I'm sure it'll be much less than that. Plus the lateral location of the inner cv joint can be adjusted to put it inline with the upper and lower joints as well which might help. On the knuckle, I tried to get the joint inline with the uniballs so that there is no steering plunge.


So after running through a bunch of different ways in my mind to relocate the lower mounts, I came to the conclusion that there was no good way to do it and not have it look like crap. Generally my philosophy is "don't get it right, get it running" but I'm really shooting for the opposite this time around. So after wasting time trying to change the subframe, I started on a better way.

I used some of my tube tabs to hold this piece of DOM in place, with a heim mounted to the tube with two other tabs:

DSC00872 by jeremiah stewart, on Flickr

This allowed me to get the lower joint moved down 2" and over 1.25" like i need (the subframe will not be permanently connected to the tubing like this):

DSC00869 by jeremiah stewart, on Flickr

Then I bent the tip up to mate to a bar I installed that welds to my mounts that bolt to the factory tow hook spot, which is one of the strongest areas in front of the subframe. This will later be where I build my bumper and skid plate off of:

DSC00874 by jeremiah stewart, on Flickr

DSC00876 by jeremiah stewart, on Flickr

DSC00875 by jeremiah stewart, on Flickr

You can see the piece of tubing sticking out of the tow hook mount here, which will be where I can send tubing to the front for the bumper:

DSC00873 by jeremiah stewart, on Flickr

So now I've got a much more solid frame for the control arms to mount to, and will be perfect for bolting skid plates to. I'll be adding some smaller tubing in X's for strength as well. The whole thing will extend to the tailshaft of the transmission and will be mounted to the body in 8 places: front tow hooks, subframe mount, rear factory control arm bushing mount (see below), and the transmission mount spots. So basically the whole front half of the car will be tied together. I haven't decided yet how i'll do the upper arm mounts. I may re drill the holes to move the heim inward 1.5" then just run 1"DOM from the bottom of those mounts to the lower piece of DOM. But I don't think it'll look great. Might ditch the subframe i made and replace with 1" DOM.

This is my mount that takes the place of factory rear control arm mount:

DSC00570 by jeremiah stewart, on Flickr
 

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Premium Member
1998 Forester S Auto
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147 Posts
Discussion Starter #14
Alright I did a little bit this weekend after making the most of the warm weather. First I cut up the subframe tremendously and bent a tube:

DSC01001 by jeremiah stewart, on Flickr

Tacked on some tabs:

DSC01003 by jeremiah stewart, on Flickr

A little mockup to ensure full droop would be obtainable without the upper heims hitting the tube they are on:

DSC01002 by jeremiah stewart, on Flickr

I then began to bend the piece of tubing that will go around the back of the transmission so that i could get the mounts figured out, but apparently when they say "up to .095 DOM" can be bent with this bender, they weren't lying. I need to get a new bottle jack now:

DSC01010 by jeremiah stewart, on Flickr

The shaft is so bent that I can't retract it at all, so the tubing is stuck under tension. I left it for tomorrow.
The plan now is to either get rid of the remaining laser cut subframe pieces and replace with DOM, or box it in and reinforce it with a small amount of DOM since it's only holding the engine and rack.
 

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Premium Member
1998 Forester S Auto
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147 Posts
Discussion Starter #17
I made some awesome progress today! I managed to get a good start on the arms:

DSC01020 by jeremiah stewart, on Flickr

DSC01021 by jeremiah stewart, on Flickr

I initially had 15.5" of travel, but after moving the upper mounts out about .5" I now have 19"!!! I think I may strap it at 18" because the upper arm would be under a lot of force when drooped far enough for 19":

20170203_184038 by jeremiah stewart, on Flickr

20170203_184100 by jeremiah stewart, on Flickr

You can see up there what the final shape of the upper arm is. I'll gusset the triangle where the uniball is and that's where the shock will mount.
Here are some shots looking at full bump:
With fender:

DSC01031 by jeremiah stewart, on Flickr

Fender removed showing a couple inches un touched to the chassis:

DSC01032 by jeremiah stewart, on Flickr

And with the tire (30" dia.) touching:

DSC01033 by jeremiah stewart, on Flickr

But the upper arm still has a lot of clearance:

DSC01039 by jeremiah stewart, on Flickr

So I'll be needing to make about 3 inches of tire clearance up top.
Finally, using a level app I have determined that the caster is right where I wanted it, at 7 degrees. The camber at ride height is showing 4 degrees, but that can be adjusted out. The CV angles are golden, and ultimately I am very happy with this.
 

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Premium Member
1998 Forester S Auto
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147 Posts
Discussion Starter #18
I picked up some thin wall 1.25 tubing for the lower control arms, but I'm still waiting on a replacement jack for my bender so i can build the driver's side control arms. I did get steering tie rod setup mocked up though:

DSC01257 by jeremiah stewart, on Flickr

It's a 3/16" thick clevis bolted to the rack with a class 12.9 M14 bolt, the heim spacer is there for mockup, and puts the joint inline with the upper and lower control arm mounts. There is a tiny amount of bump steer that seems to occur at full droop and bump, so I think I need to space that clevis out just a touch to shorten the tie rod, but we're talking like 1 or 2 degrees of toe change.

I also began talking to axle companies about some custom axles, Drive Shaft Shop wasn't very helpful or friendly and they quoted me about $1200 per axle. CVO (Constant Velocity of Ocala) quoted me $500 each. I'm not going to ask RCV because that's just obviously out of my price range. So for now, I'm going to see how it goes with CVO, they said that max plunge on their inner CV's are .75" (same as DSS) and you may recall me saying I had 1.1" of plunge, well that became 1.68" and now i have it down to a solid .875" and can't get it any lower without reducing travel. So since the plunge is equal at a depth of .875" at full bump and droop, I think for now I'll limit travel to 17" since most of the plunge is within those last few inches either direction. Then later in the future I'll run an RCV 930 cv that has over an inch of plunge with SubaruGears 930 flanges.

Lastly, after taking some more measurements of the rear end, I've figured out that there's not enough room to fit 24" of travel with dual A-arms back there because the frame rails are so low and far apart. So I think I am going to do a trailing arm setup like class 1 cars. I ran some numbers and measured, and it looks like 24" of travel is doable within the space provided and with not a whole lot of axle plunge due to the axles being so long. I wasn't able to account for setting up the axles at an angle at ride height which reduces plunge further, but i'm confident I can at least get 22" with those same 930cv's. The only drawback that I see with the trailing arm setup is that there is no camber change in the cycle, but having driven a Can-am commander quite a bit, and with the old suspension setup on the forester having almost no camber change from ride height to full compression, I can't say it'd bother me. I have no issues with it, and to me it beats having a semi trailing arm setup as well as a weird trailing A-arm setup. Plus i think trailing arms look badass.
 

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Premium Member
1998 Forester S Auto
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147 Posts
Discussion Starter #20
I finally 100% completed something!

DSC01299 by jeremiah stewart, on Flickr

DSC01298 by jeremiah stewart, on Flickr

DSC01297 by jeremiah stewart, on Flickr

The new engine mounts put the engine 1" lower than with the stock mounts, which got my cv plunge down to 7/8" and I went with polyurethane instead of moving the mount down because I don't want to run the risk of a cv bottoming out in the cup due to engine movement.
I also got the driver's side control arms started:

DSC01335 by jeremiah stewart, on Flickr

And here is what i was talking about for the rear subframe mount:

DSC01334 by jeremiah stewart, on Flickr

Here are some fun to look at pictures showing most of the travel. The jack doesn't go high enough or low enough to get it all, and keep in mind the rear is on jack stands and the tires are 30x9.5r15's but actual diameter is only like 29.3" new:

Ride height:
DSC01302 by jeremiah stewart, on Flickr

Almost full droop:
DSC01304 by jeremiah stewart, on Flickr

Almost full compression:
DSC01306 by jeremiah stewart, on Flickr

Clearly if I nose it into the ground it won't be a great day. But that's what i get for choosing an H6 that sticks out front super far.

DSC01307 by jeremiah stewart, on Flickr

That's it for now, but I've got a lot of goodies on order so stay tuned.
 
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