Input, Next Project , 40 Body on Late RJ/LJ70 Chassis which has Coils all round, 12HT Engine

[watrob]

Ahhhh thanks for your response. Ill have to play by ear then. Cheers

If your placing a metal body on then you will need to move the brackets on the chassis fit the 40 series body mounts.

 

[nerdstar]

Thanks any input you have will be great, im still in the early stages however with the RJ70 being so much wider than the FJ40 i really dont want to inboard the mounts. Im thinking of perhaps relocating the mounts on the body a bit wider. This way hopefully inside the chassis rails i wont have any body mounts. Under the tub seems to be adequate space to move the mounts a bit closer to the edges.

 

[watrob]

I don't have a mounting problem as does a steel tub. The beams are wider than I have marked here, also my tubs are extended so it will still bolt at the rear onto the 70 series rear chassis cross member.

 

[watrob]

Bib & Radiators in these positions at first measurements, yet to be double checked.

 

[cult45]

..RJ70 1988 model, will take early model 80 series coil springs..View attachment 931212

watrob these earlier coils, are they a different diameter are they?

 

[watrob]

Have not checked yet but believe 80 series coils will fit?

 

[cult45]

Yeah I've heard that too. Clearly there's a different weight requirement for a Bundy vs an 80. I know the early 80 series ran a narrower axle, just wondering if they ran a narrower diameter spring too.

 

[cult45]

watrob you couldn't do me a favour and measure the length of the Bundy front radius arm could you? Need it from centre of rear pin to the centre of the where the axle would be [halfway between the two front pin holes].

 

[watrob]

Will check on Monday as the chassis in my second onsite garage.

No the spring diameter are all the same for the 80 series, Nissan Patrol springs will fit also. As I am installing a 12ht so I will need heavier springs?

 

[cult45]

Thanks mate I appreciate it. My thought is to find the weight of a 12H-T and see which 80 series engine is nearest in weight (keeping in mind you can go slightly heavier by ordering springs which are winch/bull bar ready) and fitting those. That's the shake of all this custom stuff, it's trial and error which can get pricey.

 

[White Stripe]

So what are you trying to achieve with this build? You just wan't a coil sprung rig rather than leaf spring? If so why? Just curious.

 

[watrob]

I already have one completed and am working on a second, but this time rather than fitting the coils to a 40 series chassis use the RJ70 series chassis as all the work is already done. If you drove a all coiled 40 you would go back to a leaf sprung one?

 

[White Stripe]

I love your build their in the pics. I think a leaf spring suspension can be made to ride nicely. A spring is a spring-if its leaf or coil or torsion bar-they are all springs. The build of the spring whatever the type is whats important. A stock fj40 leaf pack will ride rough, but with modern custom variable rate leafs along with correct alignment settings it would ride comparably as smooth-even down the highway.
Anyway I was just curious what it was that made you choose coils-and its the ride you get you say. Ok cool I understand. Thats what I was wondering. You are also concerned about rust out their near the beach. So I guess while you can get leafs to ride and handle well, they do rust more than coils and links-so now I get what your thinking. I think this will be a cool build.

 

[watrob]

Yes maintenance is a big concern, second hand 80 series oem coils are $50 a pair from the wreckers, (now have 4 sets) and they take 10 min a side to replace. And, well as a 40 leaf suspension rides on the road, they are bone jarring in the rough and a low speed vehicle at full tide up high in the soft deep tracked cut up powdery beach sand which does not work for me.

As I am pulling the dead weight of a 478kg 3 person jet-ski at high tide requires suspension that can handle rough at speed as momentum is required because if you bog down you just dig 4 holes?

 

[Aussie FJ40]

Yes maintenance is a big concern, second hand 80 series oem coils are $50 a pair from the wreckers, (now have 4 sets) and they take 10 min a side to replace. And, well as a 40 leaf suspension rides on the road, they are bone jarring in the rough and a low speed vehicle at full tide up high in the soft deep tracked cut up powdery beach sand which does not work for me.

As I am pulling the dead weight of a 478kg 3 person jet-ski at high tide requires suspension that can handle rough at speed as momentum is required because if you bog down you just dig 4 holes?

I live in the largest parabolic dune system,most definitely one of the largest in OZ and its about tyre pressures not momentum,I cut my teeth in sand and have been driving in some of the largest dunes on offer and it's tyre pressures,TYRE PRESSURE, I have seen my kids when they were 8 and 10 years old drive around so called experienced four wheel drivers in our dune systems in an old 1975 rust bucket Toyota

 

[cult45]

White Stripe I agree with some of what you're saying mate but I can't come to the table with springs being springs. Can't remember where on here I saw it but the quote was something like 'Leaf springs will never be as smooth as coils because the locating rod and the spring are one and the same. To achieve true suspension, the spring must be a separate item to the locating rod.' or something along those lines. I never thought about it like that until that point. I drive a leaf sprung middy and after two years I'm now finalising my research for a front coil conversion using 80s stuff.

And Aussie FJ40, yep, sand is about pressure. And momentum

 

[Aussie FJ40]

if your tyre pressures are correct you can stop/start in any sand,momentum is used by people with no abilities in sand driving,I have proved it hundreds of times that if you have correct pressure you can drive how you like,if what you say is correct that would mean you can't go forward after you have stopped, I can stop in powdered sand and take off normally,no big revs or riding the clutch,some people think 20psi is letting their tyres down,where I drive 20 psi won't cut it,I don't agree on the momentum theory sorry,come up here and I will show you sand,a beach is basically flat so momentum is only needed if you have incorrect tyre pressures

 

[cult45]

Thanks mate, but I think I'll pass on the driving lesson. In case you missed the smiley face I was offering my opinion. Which I'll retain. I believe it's about both.

 

[Aussie FJ40]

Thanks mate, but I think I'll pass on the driving lesson. In case you missed the smiley face I was offering my opinion. Which I'll retain. I believe it's about both.

you will get the hang of it one day,it's about facts,sometimes what you believe is not necessarily correct and that belief can cause you trouble

 

[cult45]

Thank you for taking the time to school me Aussie. You know, sometimes I forget new I am to all this and how much I don't know. Luckily for me and the rest of the guys who clearly don't know what they're doing, there's blokes like you willing to offer up the cold hard facts of sand driving. It's important for a man to have a skill in life.