Discussion: Ultimate buggy

[maddog]

Not sure if this belongs in the febrication section or the rock crawling section, but I guess here's the most appropriate place.

If you were building the ultimate rock crawler, what parts would you use and how would you build it? Here are some thoughts.

Chassis. Obviously it's going to be a single tube framed unit. Would you:

- Design something from scratch and build it yourself
- Design something from scratch and have someone build it for you
- Buy an existing set of design plans and build it yourself
- Buy a pre-made chassis that someone else has off-the-shelf
- Buy a pre-made chassis with some modifications

Wheelbase? Although you might not have much option if you buy something off the shelf.

- 100"
- 105"
- 110"
- 112"
- 116"

Engine. Seems everyone likes the big numbers.

- 2.0L naturally aspirated
- 2.0L turbo
- 5.0L Commodore motor
- 5.7L GenIII commodore motor

What about front mount, rear mount or mid mount? I think you'd have a hard time mid mounting the V8 engine options though.

Diffs. Do you go with ones that are cheap and easy to find parts for, or do you build something that's more expensive and bullet proof.

- Unimog diffs
- D60's/Rock crushers
- GQ/GU diffs

Suspension. There's pretty much only two real options you'd consider here

- Air shocks
- Coil overs

But in terms of your conrol arm linkages, there are also a couple of options

- 4 link front and rear
- 4 link rear 3 link front

I'd say an auto gearbox would be pretty much standard in any rock crawler, whichever auto matched the engine used. But what about transfer case?

- Atlas II
- Dana 300
- Dana 20
- Hilux t/case
- GQ/GU t/case

Wheels and tyres? There's infinite options here, I'll only list the ones I'd consider

- 15 or 17" wheels?
- 38, 40 or 42" tyres. Either TSL/SX or IROK

Things like hydraulic cutting brakes are pretty much standard, front and rear mounted winches hooked up to the diffs.

What's everyone's thoughts? I've got a rough idea of what I'd like to do, but there are so many options.

[Wooders]

My 2 cents:
Chassis - Design something from scratch and build it yourself...would be half the fun

Wheelbase? 116" Big rubber means you want a long wheelbase.

Engine Lexus V8 - cheap, light and can produce serious HP. Mid mount would be ideal - but then WTF do you sit. I'd probably go traditional Front mount (I don't like the idea of a big fat lump of metal sitting behind me if there was a chance of a sudden stop )
Although something smaller would be nice.....

Diffs Mogs would be my budget pick, something like the PSC HiMark or the sunray 9" hybird portals would be my pick.

Suspension Nope would still go airbags - but a little different again
Linakages probably just a 4 link F&R.

Gearbox & transfer 4spd is useless for a buggy....So I'd probably go something like a TH350.
Transfer case - definately Stak.

Wheels 20" and bling ones at that.....I'd go staun internal bead locks (since mud isn't likely to be an issue).
Tyres Either Irok (mixed surface) or MTR (sharp rock) Absolute min 40".....
I definately would not go 15-17" rims as I think under throttle and on side hills there's too much sidewall movement.

[maddog]

I'm seriously pondering building a chassis myself in the garage. My main problem is I don't have a tube bender that will bend that sort of stuff. A little hydraulic jobbie won't really cut it. Also of concern is the fact that I'm not an engineer, so I'm not sure my own design would be structurally sound.

I forgot about the Lexus V8 option. I'm wondering if it's really cheaper to get a Lexus front cut over a Commodore front cut? Basically I'd be after the cheapest engine I could get my hands on that delivered a lot of power. Preferably also with the least amount of weight. I'm guessing the Lexus V8 or the 5.7L alloy engine would be the winners in terms of minimum weight.

I saw a set of mog diffs going for $5k on Outerlimits. Seems reasonable for a very strong diff with factory lockers.

[ARB87U]

what about a something like the 6A12 DOHC 24 valve Mivec?

[Wooders]

Chuck your old bender on ebay.
Since a Tube shark is probably outside your budget (WAY outside mine) - look at something like This - keep an eye on ebay for my current benders soon
Also grab a notcher - I'm looking at one like This

[Wooders]

$5k mogs - not bad, but not brilliant (IMHO)......."Tailshaftkit"...ie is that including the Torque tube and you do the Pinion conversion, or is that without the torque tube all together??
Also that's without disc conversions I guess??

Although the drums weight a heap - for a buggy the drums aren't a bad option - since the 2 main weaknesses of drums are heat dispersion & water resistance - neither an issue really for a buggy.....although you still have the massive weight penalty with drums.... It also means you could probably run them withouut a booster - ie brakes at any time engine running or not.....

[Glenn]

Chassis - build yourself is really half the fun, would rather build something that resembled something, like a flat fender willys would be easy

Wheelbase: around 110 inch

Engine : wouldn't use anything too high tech, hell would freeze over before any toyota or holden engine found its way into anything i build lol, I recon a 360 mopar running lpg.

Diffs: I don't know what rules say in this sport but I'm surprised nobody uses hydraulics, I mean has anyone operated a bobcat? those things are awsome, imagine a hydraulic motor mounted to each wheel, no axles, no uni's, no diffs, no drive shafts. and instead of a transmission and transfer case, just a hydraulic pump. You could have skid steer as well as normal steering. Of course all this would mean a fairly slow top speed but how fast do rock crawlers go? pretty slow from what i seen.

Suspension: nitrogen gas over hydraulic and probably independant if using hydraulics.

Gearbox & transfer: Hydraulic pump


Wheels and tyres: bigger the better I guess
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