Pirate 4x4 banner

rockbuggy, and H1/HMMVV suspension

34K views 54 replies 31 participants last post by  Bebe 
#1 ·
The Chile Challenge made me curious. Lots of diffs hanging on the rocks. Buggies are as big from corner to corner as the H1/HMMVV anymore. The friendly branddickering with one of my pretty extreme rockbuddies, makes me wonder WHY not independent suspension. We used to drive the lifted TJ, and dare not to have air under a tire, so now we have air under a tire immediately, and keep going. I guess one would need some serious rocksliders, and certainly remove most of the body (like some MOGs I saw). Anyone done/doing this?
 
#3 ·
Thanks for links, interesting. Would never chop my truck anyway. But was wondering why the crawling buggy people are so much into this solid axle thing. I was definitely thinking to use geared hubs, thats what makes the Hummer so capable. If a fully (over)loaded H1 makes it up Hells Gate (over 12000 lbs), how would such a truck perform stripped to basics (like the MOG was).......
 
#5 ·
]

These are pics from an Ebay crawler sale about a year ago, I don't know who bought/sold it, I just thought it was cool and showed that a Hummer IFS portal setup could be made to flex. The Hummers are just WAY too oversprung, but with the right setup, it could be made to flex more.
....except that what you are looking at is NOT an IFS setup, it's IFS parts in a solid axle cradle deal. Notice the lack of pivots, and look at the pic of the front end flexed on that rock.


Walker Evans tried IFS for crawling, and he's not doing it anymore. Why not? :D Solid axles lift the vehicle away from obstacles when one end goes up, IFS just sucks up into the body, and doesn't help w/clearance.

Not saying it can't be done, just that it isn't.
 
#8 · (Edited)
HMMM! I just got an idea! If you did a suspension kit like this, would it be possible to engineer a hydraulic wheel leveler that keeps the wheels parallel to the body. This would maintain most of the on-road characteristics that make IFS so attractive, while still giving you the flex of a solid axle rig, or is it just too complicated? In theory it seems pretty simple. Couple of rams, some "an" fittings, and a bit of steel braided hose connected to the shocks pushing/pulling the portal upper connections in/out....IT COULD BE DONE!!! or can it?
 
#9 ·
Mabye I'm missing the point but if you ran an airbag suspention with a cross over line from side to side wouldn't it act like a solid axle? When one tire goes up the other goes down keeping the tires on the ground. Solid axle caricteristics with independent clearance. And you would be able to raise and lower the vehicle for clearance as needed.
 
#10 ·
This is true and I know two guys who did this (me being one of them). It's dangerous on the road, but cool on the trails. You still have the lack of travel issues, but that can be slightly improved by limit straps, longer shocks and balljoint mods. My bags are now independantly controlled for safety/convenience, but if it was purely a trail truck...

rb
 
#11 ·
Independant doesn't climb the same, break-over, or turn and climb nearly the same as straight axle. Nobody has made it work in numerous attempts, even the "father" of long-travel desert race suspension, Walker Evans.

Steering was a small issue he was having...a big drop in big obstacle performance was the main reason.
 
#17 ·
I would love to see more experimenting with long travel IFS for Rock Crawlers. Everybody knows Walker had a hell of a time with it, but he also didn't run it very long and I would agree that the arm set-up he was running was part of the issues he was having.

ANd let's not leave out Randy Ellis' Red Racer. IFS and IRS and he did OK in a few of the rock crawl events he ran it in.

It was being discussed on Racedezert awhile back and one of the guys was implying that using the Hummer portal with IFS would reverse the lifting effect and help IFS bite more. Not sure why, but something to look into.

We got a chance to run a Total Chaos long travel equipped FJ Cruiser around the Hammers at the KOH and we were impressed as hell with it. It only had 32s on it so we were doing extremely mild stuff with it (read that no hard core trails), but it climbed up and over the rocks that were in our way and some of them we thought no way. We had more issues with hanging the under body up on stuff than we did with the front end hooking up. Big heavy rig + little tires= bellying most stuff.

I would like to see that suspension under a small lightweight buggy with 37s..... hmmm, maybe that's what we'll build for the KOH '09... :laughing:. That is if we can get an invite. The biggest issue will be coming up with some CV assemblies to handle the load.
 
#18 ·
Hey Tom, it's not a driver yet but will be in a few months. It has an H1 body with Cummins 12 valve, Klunvee, Unimog 416 (front/rear steer) 50" Michelins, large air bags. Can't wait to go on the Rubicon soon with it. In fact, I mis being there so bad that I am taking my Cub Scout Den there this weekend. We are going to hike the Rubicon!

Brian
 
#20 ·
Hey guys....

Hey, my name is Rusty. I am brand new on here. I actually just signed up so that I could reply to this thread.

Here is my idea, and some of you may think it's extremely stupid, but again, it's just an idea I've had in my head for a long time, but never seen it put into form.

So, my idea is to run a fully independent suspension, independent front and rear suspension with portal hubs on each wheel. Of course, being that it would be IFS & IRS, upper and lower a-arms on each corner with shocks maybe running in front of and behind the axles inside of the a-arms mounted to a shock hoop in each fender well. As far as the shocks go, I would like to see this done for some of the reasons you guys were talking about. So, to begin with, it is a big reservoir shock, with coil over option. The coil overs would be split up, a big 3/4 length spring for big heavy drops and then a harder one to eat up the bumps in high speed. Then, on top of the shock, between the top of the coils and the shock hoop, an independently controlled airbag on each shock.

I have just had this idea in my head, like I said, but have never seen it in person or been able to sketch it out correctly to get a good visual of it, so if it turns out being really ignorant, just tell me, it won't hurt my feelings.

The airbags could be emptied and filled depending on which side is crawling up a big rock, to lift the body away from a rock or something, like with a solid axle setup, then leveled again when normal driving on flat surface. This way, you could get lower gearing with the portal hubs, the IFS & IRS handling on the road, like sports cars have, and the airbags over coil overs to give a leveling kind of solid axle support.

Does this sound ridiculous?? I get that it would be extremely expensive and need some serious work to put together, but I just think, theoretically, that it would work better than any solid axle or IFS setup currently out there.

Let me know what you think guys!!

Thanks.
 
#22 ·
Wow, it might take me a minute to wrap my head around the airbag portion of it...but it almost sounds reminiscent of the Land Rover?

Is this for a trail rig? Or is it for a racer/crawler?

There is another conversation going on in the Desert racing section on IFS/IRS. http://www.pirate4x4.com/forum/showthread.php?p=14037327#post14037327

My only .02 for go fast and portals is this:

Think about what, why and how portals were designed and their intended use...

1) it was made for heavy loads and increased gear reduction to move those heavy loads
2) all of the vehicles that currently have portal have a max speed of 70 mph, and they are not happy at that, especially for sustained periods of time.

If you are using portals, for rock crawling - you really have the clearance necessary already H1's have 16" at the center. Put those portals on a tube frame IMHO you're golden, add bypasses and coil overs keeping the double A-Arm and you have yourself a pretty cool machine.

H1's are awesome rock crawling machines - I'd own one if I could afford it :)
 
#23 · (Edited)
If you could mount the coilover eye to the lower end of the airbag itself then it may work. But the bag would have to have some "runners" or better yet "tracks" on say 3 sides to keep the bags from deforming(one side bulging). Plus you'd have to have some durable air bags....like from a Kenworth or something. But with only say 6" of travel.

EDIT* HOLY THREAD REVIVAL ROBBIN!
 
#24 ·
What would a Humvee frame with axles be worth to you guys if I said I can get my hands on 50 of them?
 
#30 ·
Post them up Bradley! Would love to see them.

Whoever the poster was didn't know what they were talking about or it was taken out of context. A portal box top speed would only be limited by combined vehicle gear ratio, tire diameter and engine RPM. I guess box design could limit top speed as far as longevity or strength, but that wouldn't play a part with a Hummer gearbox, they are plenty beefy.

BTW- good to finally meet you face to face, sorry we didn't get a chance to talk more outside the contingency interview. Unicorns and 4 leaf clovers, hah!
 
#33 ·
hey if any user found our spare tire, and our tool bag lost somewhere between the start and mile 19? I would be glad to trade it back for fabwork or build custom shocks for it??? the tire was on a KMC wheel and had a 39 inch bfg project, with a proto-type tire inflation system on it.:confused:
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top