Gawynz Buggy Thread

Gawynz

Member
Location
Ogden, UT
Well, I've put this off for quite some time but I'm finally getting around to starting a thread for my buggy. First, the introduction.

One of the reasons I'm starting this thread is I'm getting ready to redo the suspension. Throughout my research I actually stumbled across the original build thread for my rig on RME! @CSR originally built this buggy and he did an awesome job! I bought this rig from him back in the spring of 2017. For those of you who have seen my buggy, it has a pretty unique suspension design and I'm a big fan of the concept, you can check out the original build thread here: https://www.rme4x4.com/threads/buggy-build-suspension-experiment.110938/.

So I grew up rock crawling with family and friends and always wanted to build a buggy. Post college I moved out to Utah, started working, and starting saving to build a rock crawler. I came across what's now my buggy on KSL; it had 90% of everything I wanted at the time and the price was reasonable, couple that with the fact that the apartment and small garage I was renting in an overly sensitive HOA at the time didn't lend itself to building a buggy I pulled the trigger. I've wheeled this up until now with fairly minimal changes, so far I've:
  • Sold the 40" Pro Comp Xtreme MT's and replaced with 45" TSL SXIIs
    • On about the third trip out playing around BFE I tore the sidewall of one of the 40" tires, figured it would likely happen again after reading several reviews so I got rid of them. Also, I love how low the rig sits but it was realllly low with 40's, stepping up to 45's (actually around 44") made a huge difference crawling and the drive train up until now has handled them just fine.
  • Replaced the 14 bolt wheel seals
  • Replaced the stock Ford Dana 60 manual locking hubs with TMR drive flanges
  • Rebuilt the front skid plate as it interfered with the leading arms during articulation
  • Rerouted the hydraulic steering lines
  • Added wheel spacer to the back end because during full articulation the tire would rub the coil over, this also matched the front and rear track width
  • Replaced the seat belts with Crow Enterprise 3" four point harnesses
  • I actually 3D printed some nylon coil over reservoir mounts which turned out really cool and have been working well (I should post something on this later)
  • Due to the drivers side exhaust manifold location I was burning plugs in two pretty bad so I rerouted/shielded them
  • Built a hydraulic steering cooler shield as it was in line with the tire roost and at risk of me kicking it in when I got in and out
  • Removed all the polycarbonate windshields as they got scratched and dirty and difficult to see through
  • Built a couple ammo can tool box mounts
  • Replaced the starter
  • Maybe a couple other little things...
So... as you can see, not much and really nothing too major. This thing was built very well and I've had a blast wheeling it so hats off to @CSR. Here's how it sits now alongside a few other RME'rs rigs from a trip to Moab last year.

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And another picture... (this one you can see a lot of what I'll be talking about below)

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Aaaand one more.

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Recently I purchased a house, and along with that house, an actual shop and no HOA! Finally getting everything settled in and as Spring is quickly approaching I want to change things up a bit on my buggy suspension wise. So throughout the original thread this things been referred to as an experiment, which it definitely is in terms of suspension. So here are my impressions of the results from this experiment. A few details related to stance and suspension geometry:
  • Wheelbase = 120"
  • Track width, outside of tire to outside of tire = 98"
  • Belly height = 17.5" (only ~15.5" before I swapped tires!)
  • Rear 18" 2.125 ADS coil overs mounted directly to the axle, only ~4" of down travel, duel rate coils at 100#/400#
  • Front 10" 2.5 ADS coil overs mounted to the leading arms ~50/50, only ~2" of down travel and only using about 8" of total travel due to limit strap, single rate coils at 400#
The thing is incredibly stable, and I really love that aspect of it; but there are compromises being made for that stability and there are a few other details related to the suspension that I'd like to change to continue the experiment.
  • It's pretty fast and rides fairly well through the rough stuff, but not as well as I think it could
    • I think this has a lot to do with three things
      • The valving in the front end
        • The rebound is stiff and the compression is very light (you can read the thought process behind this in the original build thread). If you go too fast or hit something too hard, the shock will blow through the stroke and bottom out
      • The lack of droop
        • As mentioned above, I have very little down travel. Down travel is limited by the driveshafts (both front and rear) contacting the frame as well as the current coil over mounting positions
          • If you go too fast through the whoops the tires can't maintain contact with the ground and it gets pretty jackhammer-ish real quick as the axle flies through the compression stroke with the light valving loading up the coil and then smacks the limit strap on the rebound
      • The rear coil combo
        • From what I've learned, the 100#/400# combo is a very large spread. What I've witnessed is that often times the top coil is fully collapse (bind) and I'm riding a lot on the 400#. For comparison, the rig is weighted very evenly front to rear nearly 50/50; and I have 400# coils on the leading arm setup in the front (lots of leverage) and essentially 400# springs mounted directly to the axle in the rear (no leverage) which I think is contributing to the harshness in the back end.
  • Rear steer
    • Not the good kind that I wish I had with such a long rig ha... So due to the tall height my axle side upper link mounting point, and the fact that both the upper and lower links are relatively flat, the roll axis of the axle (from the upper links LCP to the lower links LCP) is relatively very steep leaning forward. When the rear end articulates, you can feel the back end walk side to side. Given the geometry, i'm sure the same thing happens in the front but you just don't notice it with the steering axle.
  • Down travel and belly height
    • Sharp break overs destroy me. I'm not even close to being able to go up the rock pile at Moab and the son of rock pile even gives me fits (it drives me crazy). This buggy is great at steep stuff but if it has a sharp break over at the top I'm screwed. As a few RME'rs can attest after stacking rocks for 15min after I got stuck on our trip to Coyote Canyon, boulder fields aren't my cup of tea either.
  • Bump stops
    • The ADS coil overs have a ~1" rubber bump stop on the bottom but that's it. The addition of bump stops not only would help the ride but also would save my coil overs.
  • Single Link
    • The top links are really a wishbone setup, two heims at the chassis and one at the axle side. Due to the large link spacing I have at the axles the single upper heim has a lot of leverage to reduce its load, but just having a single failure point worries me. If that single heim was to break there's nothing to stop the axle from wrapping up and causing who knows what damage.
Soooo.... Now my suspension plans.
  • Raise the belly height
    • This buggy is very fun to drive with the CG being below the vehicle roll axis; at speed it tucks into the corners (opposite of body roll) and in off camber situations it actually leans up hill. Raising the belly height puts me at risk of losing these characteristics so I'm trying to balance the increased belly height and stability. On the other hand, I think it will help to raise the belly height for cornering because currently this thing loves to drift, raising the belly height will transfer more weight to the outside of the outside tire providing additional traction.
    • My plan is to raise the belly from 17.5" to 20". Increasing my tire size ~4" provided about 2" of lift which made a hug difference, so I'd expect this ~2.5" to significantly help as well.
    • Raising the belly height should also give some slope to the lower links raising the lower link LCP and reducing the amount of rear steer
  • Get some droop
    • The current limitation to droop is my drive shafts hitting the frame. I plan to run two piece drive shafts front and rear, remount the coil overs and target about 50/50 stroke up/down (still kicking ratios around). Again, this extra droop may lead to the CG going over the roll axis for an instant throughout the travel... but it's an experiment after all so we'll see.
  • Coil overs
    • Front
      • Remount
      • Revalve the coil overs to a more traditional valving style
      • Go to a duel rate coil over setup
    • Rear
      • Remount
      • Respring the duel rate rear for a more subtle transition/shared load
  • Add bump stops
  • Change over from the wishbone top link setup to two separate top links
The other night I took a bunch of measurements and pulled the drive shafts, limit straps, and coil overs and have it sitting at the new belly height. My plan is to articulate the front and rear to see if I have any interference with the 50/50 uptravel/droop utilizing the current linkage. Now that I've got a thread going I'll update as I go.

So everything above is just how I understand the various topics/theories; I've learned a ton from this forum and other forums like it and I'm definitely looking for different thoughts and opinions so if you guys have ideas I'm all ears.

:beer:
 

Ashcat

Active Member
Location
Wisco
I vaguely remember the original thread.

You’ve got some good plans going forward and I’ll be watching
 

CSR

Active Member
Location
Mapleton
Good to hear that the rig has been enjoyable for you despite some of my suspension misconceptions. Also good to see the continuation of the experiment. I'm interested in the results, as i am currently working on a bigger 5-seater that will use the same suspension concept.
 

CSR

Active Member
Location
Mapleton
The rear drive shaft is fairly close to its safe spline engagement limits with the current suspension setup. Be sure to pull the boot and check that after your modifications.
 

xjtony

Premium Member
Supporting Member
Location
Grantsville, Ut
It's still amazing to me to see how much lower your roof height is than mine in the picture from the Pickle parking lot last year. I was running 38s that trip and you are noticeably lower even on the 45s.
 

Gawynz

Member
Location
Ogden, UT
i am currently working on a bigger 5-seater that will use the same suspension concept.
Looking forward to seeing this!

The rear drive shaft is fairly close to its safe spline engagement limits with the current suspension setup. Be sure to pull the boot and check that after your modifications.
I'm going to have to change out the drive shafts and run two piece drive shafts front and rear. Currently, I'm planning on running Tom Woods two piece drive shaft, I like that each shaft has a slip in their design and I know @Herzog and a few others have had good luck running them (also their shop is literally 4 miles from my doorstep). If anyone has any other suggested companies/options for a two piece drive shaft let me know. I considered notching the frame and sticking with a single shaft as it helps with u-joint angles, reduces complexity, and is cheaper, but I'd essentially have the cut the frame in two to get the droop I'm looking for so that's not going to work.
 

Gawynz

Member
Location
Ogden, UT
It's still amazing to me to see how much lower your roof height is than mine in the picture from the Pickle parking lot last year. I was running 38s that trip and you are noticeably lower even on the 45s.
His roof height matched Greg's willys! :rofl:
I love that picture next to @Greg's Willys haha. On that trip I think we determined:
  • The buggy's rubber is taller than any piece of sheet metal on the jeep (w/ windshield down)
  • The buggy's roll cage is slightly lower than the jeeps roll bar
  • The buggy's wheel base is nearly the same length as the entire jeep length
  • The buggy's track width is wider than the jeeps wheelbase
All that being said... that entire weekend I'm pretty sure @Greg drove the Willys up and over every single obstacle that I did unassisted :(... so much for the big bad rock buggy... haha :rofl:
 

Gawynz

Member
Location
Ogden, UT
Made some progress this weekend. It was good to because it also kicked me into gear organizing my shop a bit; I installed some additional shop lights, added a new 220V 30amp breaker/pug outlet, and tool organization pegboards and what not... Still kind of a mess, but progress.

Pulled the drivelines and both have been rubbing on the frame during articulation, the limit straps were right on the edge, the rear is actually crimped/necked down to a smaller diameter haha. I knew this was happening obviously but I didn't quite realize how much.

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Definitely bottomed out the front end a few times, I actually had to cut off and drive out the passenger side axle shock mounting bolt as it was pretty bent. I'll be replacing everything related to my shock and link mounting with Grade 8 bolts if it doesn't' already have it (this one didn't).

Sitting at it's new, 20" belly height, axle at weighted height for ~4psi tire pressure (SXIIs are stiff!)

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Once I had the belly height set I wanted to articulate the rear end with the current linkage to see where I'd get interference. I don't plan on changing the axle location, just linkage so this would give me a starting point.

Full stuff was obviously just fine, this is about 9" up.

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Droop is where the issues came in... I only had about 4" of droop before the upper links hit the exhaust, funny, it's almost like somebody designed it this way! :rofl: So I'll be rerouting the back end of the exhaust.

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Also at ~4" the link started binding with the mounting tabs, but I'll be redoing this anyway.

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So out came the exhaust and the lower links were removed. I used some tape (shows drive shaft angle and full bump) to try to map out in my mind where I'd run the exhaust at the end of all this to make sure it wouldn't bite me in the end, fingers crossed I have a plan.

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Then I started chopping... I swear I stared at this crap four hours trying to think about what I missed before I finally pulled the trigger. No going back now. Before.

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Where I finished last night.

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I left the upper wishbone in place for now to help locate the axle.

My plan is to add more triangulation to the lower links (previously just under 30deg link to link), shooting for 45deg on the new setup. My thought behind this is that I think they take a serious amount of the load when a side force is applied. People tend to refer to the top links taking the bulk of the side load but with my top links mounted so high I'm thinking it applies a torque trying to lift the opposite side wheel as the impact and the lowers pick up the slack. Whereas if my top links were mounted lower they'd laterally locate the axle more and not try to lift one side or the other. Even if all this thought in my head is BS, from what I've read one should target a 40deg minimum lower link angle if there is clearance to do so. To move my frame side link mounting points inwards I had to chop off the exhaust shield/tubing which I'll fix in the end.

The other thing I kind of ran into issues with is the drive shaft angles. Currently I run 1350s and I was hoping to do so in the future with the two piece drive shaft, but the back driveshaft angle is too steep. I plan to use my linkage to keep the pinion angle relative to the carrier bearing at a safe 1350 operating angle. For the middle u-joint I'll have to run a 1410 to handle the droop. The transfer case u-joint will be a 1350. I wanted to keep them all the same but it's not looking possible.

So that's about it for now. Need to order some 3/8 tabs/plate and finish cleaning.
 

Greg

Wanderlusting
Admin
I love that picture next to @Greg's Willys haha. On that trip I think we determined:
  • The buggy's rubber is taller than any piece of sheet metal on the jeep (w/ windshield down)
  • The buggy's roll cage is slightly lower than the jeeps roll bar
  • The buggy's wheel base is nearly the same length as the entire jeep length
  • The buggy's track width is wider than the jeeps wheelbase
All that being said... that entire weekend I'm pretty sure @Greg drove the Willys up and over every single obstacle that I did unassisted :(... so much for the big bad rock buggy... haha :rofl:
That was such a fun contrast with the Willys and your Buggy, pretty amazing to compare them side by side, then go run a challenging trail with both totally different rigs!
 

Gawynz

Member
Location
Ogden, UT
Didn't have any time to work on the buggy this weekend as I had family in town; on that note, a quick detour. My brother is rebuilding my Grandpa's Willys; not a show car or anything but just a fun rig to drive around town, canyons, and mountain roads. He's rebuilt the motor, transmission, transfer case, axles, steering, etc... most of the major components. The big issue was the frame he had had been stretched as well as the body and they were both a mess. A Willys popped up on KSL with a pretty good body and frame but no motor at a reasonable price, it was exactly what my brother was looking for. So my sister in law and I plotted a surprise. I bought the jeep for my sister in law and brought it home, my brother was getting excited and planning on coming up last weekend to hang out and to check out the Willys. He went to call the guy to schedule a time to check it out and it was sold... he was pretty bummed. They came up anyway and they'd never seen my new house so I gave them a tour throughout the home and then we headed out to the shop where he wandered in to find his jeep tucked away in the back corner haha, it was pretty fun.

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Gawynz

Member
Location
Ogden, UT
Back to the buggy... Last night I got around to cleaning up the axle and start setting up the lower links. Tabs are made from 3/8" plate; started with cardboard templates then using the SWAG Offroad Portaband Table cut them out of plate. Should be able to get the 45deg I was targeting out of my lowers.

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I'm going to increase my heim tab spacing because with these bulky rebuildable heims the body actually contacts the tab before reaching full lock. Adding a washer on each side between the tab and the misalignment spacer does the trick.

I also picked up the pillow block for the two piece driveshaft and talked with the guys at Tom Woods Custom Driveshafts about my plans to run 1350 at the diff and transfer case with a 1410 in the middle for u-joint angle reasons. Then they informed me that I was misinformed haha. So a 1410 can handle loads at greater angles but that doesn't mean that the yokes will allow those angles. They said that using a 1410 instead of a 1350 would only add a few degrees extra and unnecessary strength at that one joint. If I really wanted to utilize all the angle the 1410 can handle I'd have to find a different yoke combo than what they provide. They recommended I use their Superflex Joint. I'm going to try and make all standard 1350s work but in the end I might have to go the Superflex route.
 

RockChucker

English is important. Engineering is importanter.
Location
Highland
Didn't have any time to work on the buggy this weekend as I had family in town; on that note, a quick detour. My brother is rebuilding my Grandpa's Willys; not a show car or anything but just a fun rig to drive around town, canyons, and mountain roads. He's rebuilt the motor, transmission, transfer case, axles, steering, etc... most of the major components. The big issue was the frame he had had been stretched as well as the body and they were both a mess. A Willys popped up on KSL with a pretty good body and frame but no motor at a reasonable price, it was exactly what my brother was looking for. So my sister in law and I plotted a surprise. I bought the jeep for my sister in law and brought it home, my brother was getting excited and planning on coming up last weekend to hang out and to check out the Willys. He went to call the guy to schedule a time to check it out and it was sold... he was pretty bummed. They came up anyway and they'd never seen my new house so I gave them a tour throughout the home and then we headed out to the shop where he wandered in to find his jeep tucked away in the back corner haha, it was pretty fun.

View attachment 118825

View attachment 118826
I know that little Jeep...because it used to be mine! I sold it to Rick. Looks like he decided to sell it....It was always one of those one day projects....maybe one day I'll get another.
 

Gawynz

Member
Location
Ogden, UT
I love my Swag portaband table. I use it WAY more than I thought I would for many various things. It's a time saver for sure.

I can't remember, what gearing do you have in the axles?
Agreed, the Swag table is super handy. This is the first time I've used it on relatively thick plate and I was very happy with it.

Axles are 5.38
 
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