budget off roader

[BrokenBiker]

a lad i work with asked me to look over some plans he has for a small lightweight off roader...

basically he wants a space frame type chassis and roll cage, like a dune buggy, a small little 1L turbo engine, probably from a bike and for the 4wd system he was wondering if a FWD gearbox would work...

his idea is, drive rfrom the engine into the input of the gearbox, which is mounted so the output shafts go to fron and rear axles with diffs...

i reckon in theory it may work, apart form most FWD boxes being fairly crap when one wheel starts to spin...so maybe some form of locker, or weld it solid so it has to give power to both axles?

he already has a pajero, but its the family car and he isnt too keen on taking it out, damaging it and then not having a car to get back and forth to work, so the plan is to build a toy, trailer it there with the mitsi and then hoon aorund until its broken or he has had enough fun

 

[pedrobedro]

It's going to be low geared with a diff in the centre running diffs in the axles.

 

[123hotchef]

ha ha u can get off the shelve lokkas for the diffs

 

[rtbcomp]

It's going to be low geared with a diff in the centre running diffs in the axles.

You could mitigate that by fitting larger wheels than the donor car originally had.

 

[123hotchef]

You could mitigate that by fitting larger wheels than the donor car originally had.

that can also lead to no power and burnt out clutches on a off roader

 

[Charlie390]

Take one Suzuki Jimny, remove body and retain chassis, gearbox, transfer case and axles. Either keep the original 1300cc engine or upgrade and build whatever type of body you want...

 

[rtbcomp]

that can also lead to no power and burnt out clutches on a off roader

You'll get that wherever you increase the gearing, again the weight would be reduced which would help.

 

[123hotchef]

Take one Suzuki Jimny, remove body and retain chassis, gearbox, transfer case and axles. Either keep the original 1300cc engine or upgrade and build whatever type of body you want...

thats the easy route

 

[BrokenBiker]

surely you want low gearing for an off roader?

my main concern was that the gearbox wouldnt be up to much if one wheel started slipping...putting lockers in the axles would help but if an axle is slipping then no drive to the other axle

 

[123hotchef]

depends how the diffs are i have front and rear lokkas in my 4x4 so it is not a problem

also have 4 H or 4 L depending on whats needed with the bigger diameter tyres i use its in 4L more than 4H now days just cant get it moving in the normal range 4L halfs it

 

[xmetal]

Take one Suzuki Jimny, remove body and retain chassis, gearbox, transfer case and axles. Either keep the original 1300cc engine or upgrade and build whatever type of body you want...

That's exactly what I was thinking.

 

[CompoSimmonite]

The Suzuki SJ410 and Lada Niva have "divorced" transfer boxes. There is a short prop shaft from tail of gearbox to the transfer box then props to both axles. That means you can use what ever engine & gearbox combo you want.
However if he wants to use a 1.0 turbo motorbike engine it sounds as if the idea is for a powerful fast off road buggy when 4x4's tend to normally have more torque. In that case he's probably be better keeping it just 2wd (a lot lighter) and fiddle brakes for the driven axle.

 

[Rannsachair]

I would go the Jimny route too - a proven 4wd system with a low ratio box and can be bought cheaply. To design and engineer something from scratch is likely to take much more time, cost at least as much and be less capable. I have been amazed at Jimny's managing terrain my Landy struggled with.

 

[Bobtail4x4]

the tyres make most difference, and the ton or so less weight?

I saw a series one with a mini 1000cc engine and box driving the front and rear axles, it seemed to work.

 

[BrokenBiker]

to be honest, if it was me making it i would buy an s410, fit a vitara 1600 engine + axles, a rock lobster conversion on the transfer box and then pope the body off, slap a cage on and go have fun...know of a lad locally that did this exact thing and it will go absolutely anywhere, and pull defenders and series out of everything else

but my mate is a bit of an optimist and wants to live the dream so he can start conversations with 'when i started my build' at the pub

 

[addjunkie]

Suburau impreza.....some one built a quad out of one, so a dune buggy would be fun

 

[BrokenBiker]

Suburau impreza.....some one built a quad out of one, so a dune buggy would be fun

Place down here called GD environmental made a skip out of one...granted the skip is only made of 2mm rather than a proper skip but it shifts when they decide to have a bit of fun

 

[PhillipM]

I'm using that setup in the OP for my next 4wd buggy - but the problem, especially with a high revving bike engine, is getting the gear ratios low enough for big offroad tyres - you need some big, big diffs.

Make it RWD and just hold the throttle open on the tricky bits...

 

[sparkysy]

CompoSimmoniteMember
New
The Suzuki SJ410 and Lada Niva have "divorced" transfer boxes.

I had both of these and were great off roaders! Gave them both a lift easily and put snorkels on them and treated them to the best boots I could afford, great for a play! I remember pulling out discovery's and a v8 range rover in the sj with people watching pi@@ing themselves laughing. Ladas are getting rare over here now as are descent sj's!
Sy

 

[Tinbasherdan]

As a crawler type off roader it'll be about as much use as t!ts on a bull with a high revving 1l in it, next to no torque at low revs. Stick to rwd only and have some decent high speed fun, a la rage buggies etc, and tell him to forget a 4x4 system