Moving the body to improve aproach angle?

[Deface]

Hi there, i am currently planning a challenge truck build out of my quite batterd 1992 defender. I was thinking, what would it take to move the body back on the chassis to improve the approach angle?

To give you some more info on the build, im planning on useing challenge wings and the tub will be goin on a diet aswell so modication to move these back would be limited.

Thoughts please

Thanks

[Team Idris]

Is it not easier to move the axel back with that kit thingy? Then it will be 100"

But, then it won't be ALRC and MSA are sniffing around rear mud gaurds, and I get the feeling they are hitching winch-challenge to comping rather than trialing? Not sure why, but that is the feeling. So you may be putting stuff back on later?

I've been on CAD this morning looking to put some stuff back in, as I have the back end too open

Anyway, before you go a hackin', I got a hell of a help on mine with a rounded off rear cross member. (Still not ALRC though) I have come to realise that it's not a major issue to drag things along, as long as it doesn't dig in. So splipper plates on the diffs and an under-ski tube have improved my lot a fair bit.

It's not a 90" admittedly, but 90 chassis stuff is a spin off from this 1972 RRC anyway

[Deface]

Thank you for the reply team idris and i shall keep in mind what you said about ALRC and MSA rules regs etc, before i start the the build i plan on having a good read through them aswell as IVA regs.

As for my original query i think you may of misunderstood. I was thinking about moving the body back on the chassis to improve the approach angle on the front so the bodywork at the front lines up as much as allowed with the front wheels with losing the iconic defender shape and proportions.

[Team Idris]

Doh, Yeh, approach as opposed to departure

Occupational hazard of winch challenge is approaching stuff with either end So Appologies

Well, that really was a cow of a job for us. I'm well away from your truck here, as my engine is well forward on the big old rangy bell housing. But I've seen plenty of them about and the same problem comes up with the rad vs winch. Easiest fix is a rear winch with a tube to the front. Hardest is a rad move to the back. Especially if you go 'charge cooler' like Red Line Mike. But the result is very good and he gets the Td5 in there with a big front winch and a good approach angle. (Attack angle in Mikes case).

Bumper is the first to go! (Maybe the bit it bolts to, which is a bit more brutal) Then a good slippy front skid plate so it doesn't dig in. The honest truth is that when it gets realy bad, you will go down 45 into a ditch and meet the other side as a virtical face. All you can do then is waffle boards or roz' it up the other side on the winch. The least amount of mother earth you move doing that, the easier it is

Tube wings help no end as you can doze stuff out of the way with them. Clearance doesn't seem to bother folks then. No idea what the MSA think on the front wheel coverage. ALRC seem to be letting a lot more be cut off than they did?

That skid plate is 2" in front of the front cross member. For ALRC the idea was to take it off and put the bumper back on to the angle steel behind it. But that hasn't happened yet. It's 4mm 5083, and that is critical, as the soft ally like 1050 will bend very easily. I've heard of a belly pan in 6082 3mm and that is so hard it is a struggle to bend it without cracking

p.s. that angular plate would be better curved like the rear, but it isn't so bad that I would change it until I was really bored

[dangerous doug]

move the front axle forward.

[Deface]

My plan is to use a 3.9 v8 out of a disco and one other reason to move the body is so i can move the engine back aswell to improve centre of gravity and i want to put the rad at the to free up a bit of space under the bonnet.

As for moving the front axle i thought this would be more complicted having move raduis arm mounts, panard rod mount, steering box and spring hangers. Has anyone moved axle or body? Im interested in whats involed in doin either.

[sean f]

Moving the whole body would be possible but quite a bit of work as basically all the outriggers will need to be removed and repositioned, not out of the question if you are looking at lossing most of the rear body anyway and adding a roll cage you will be down to an almost bare chassis anyway. Doing this is arguable IVA territory although what can and can't be done to a chassis before an IVA is required has been discussed at lenght with no clear cut answer even from the IVA testers, people experience seems to vary depending on who they ask and where. Just look at some of the previous threads and arguments on this.

Easier to shorten the front wings back especially if the rad is going in the back but this still leaves a winch in there somewhere and doesn't allow the engine to move back as you wanted.

If you are going that far is it worth considering a full space frame of some sort, either Whitbread or QT style sort of thing this gives a lot move flexability in the build.

Moving an axle is IVA territory (if you want to be fully legal) as these are structural parts, this only makes sense as a poor job of lining things up and bad welding would result in a seriously unsafe vehicle but one that could potentially still pass an MOT which doesn't neccisarily cover these things.

Either way you also need to think about the steering links, where the steering wheel will end up, will the links reach etc, this is a safety issue but also if the vehicle is used for challenges these things will take a battering and often reliability is what sorts winners and losers at events.

If the vehicle is never intended for the road then the IVA stuff can be ignored, not sure of the individual event regs but even if a MOT is required that doesn't have to mean the vehicle is road legal, it is quite easy to have a valid MOT but an illegal on the road vehicle due to construction and use stuff. Some events use a valid MOT as a form of scrutineering and an assurance that at least basic stuff works.

[Team Idris]

The whole body

That's just bonkers, I love it

But way easier to fit longer prop and longer radious arms or 4 link.

I see little gain though for the large amount of work, as most of the time the truck is bogged or spinning on clay with 6" of ground clearance?

The thing that makes one winch challenge vehicle beat another is team work followed by reliability.

[Deface]

To move the body back is it just a case of moving the front and rear bulkhead outriggers and extending the steering column? if it is then is sounds alot easier than moving the axle forward or am i being naive? I have thought about just cutting the front of the bonnet and wings but decicded against this as i would lose the proportions of a defender and as you have said it wont allow me to move engine etc so i was looking for another way of gaining an improved approach angle. As for the IVA test i was under the impression that aslong as it was within reason and the modifications to the chassis were done safely it would be ok but again i could be being naive, i will be going through the IVA manual before the build so i dont want to focus to much on that on this thread as im sure that something like this has been covered on here before i just need to find it For now i just want to know how possible it is to move that body back the few inches it would take to create a near 90 degree approach angle.

.

[yella 90]

good approach and departure angles are vital

do abit of co driving and you will see why.

rocks, trees ditches infact anything to do with challenges the less infront of the wheels the better.

on my new build i will be moving the body back 2" as thats all it needs to get good approach angle without moving axles ect as your then into altering steering box and panhard rod positions.

will it be a road going car as thats your biggest issue.

if not the go for it and do what you think is best for you and your car

dan

[zim]

On my truck the front axle is in the standard place. It was originally a RRC chassis, but similar to a 90's i think. Everything in front of the front cross member has been cut off pretty much.

I'm not sure on how standard engine mounting would work for this as mine is a fair bit back.

G

[Deface]

@yella 90, so for your build are you just moving the out riggers and extending the column? Is that all thats required?

I am undecided as to weather the car will be road legal yet, but if i do go ahead with moving the body, will i have issues with the IVA? Im moving the rear axle so it would have to go for an IVA anyway.

[Deface]

@yella 90, so for your build are you just moving the out riggers and extending the column? Is that all thats required?

I am undecided as to weather the car will be road legal yet, but if i do go ahead with moving the body, will i have issues with the IVA? Im moving the rear axle so it would have to go for an IVA anyway.

[Deface]

Sorry for repeated post. Stupid phone!!!

[dangerous doug]

ive moved mine forward 6 inches and havnt cut the chassis down atall and the aproach angle with 37s is pretty good. im putting 44s on it which should make it better but im also cutting the front of the chassis and raising the winch tray which should aslo help. but that is with a 4link airshocks and full hydro steering.

[zim]

I spy 404's

[Deface]

Youve moved the body forward? What are the benifits of that?

I plan on useing 35s to start with which seen like castor wheels compared to 44s but plan on mayby going up to 37s in the distant future, which will effect the approach angle.

What my basic plan is at the moment to move the body back 2" or so, cut off all chassis before front cross member to make way for a bumper of some sort, move engine as far back as i can untill both props are the same length for a 100" wheelbase.

[yella 90]

ive snapped my chassis so will be going over to a 100" disco one

then i can faff to my hearts content

[muddy]

Sounds like a massive amount of work just for two inches. Why not lift the bottom of the front wings and bumper?

Or start with a 100" chassis move the engine and box back so.you could swap back and front props put a short bellhousing on and build your body around that?

[Deface]

Well if i start with a 100" chassis ive still got to change outriggers, engine/gearbox mounts,rear crossmember and modify the front of the chassis for approach angle so the only thing i gain from a 100" chassis is i wont have to move spring/shock mounts.

If i stay with a 90" and use an extended A frame or d44 bracket are there any benifits to doing regaurding axle movement etc ??

[muddy]

Longer rear links mean the axle will walk under the truck less during articulation, ideally links should be as long as possible/practical.

Are you going to chop a 90 up for this project or starting from scratch? You will pay a premium for a good 90 chassis just to chop up.

Do you compete already? What are you trying to achieve?

Will.

[dangerous doug]

axle is moved forward 6" to clear the ludacrous mog diff. i want to keep mine as low as possible, it will have no suspenson lift so extra ground clearence is provided by the 44s and the portal boxes.

were talking about sva stuff now, if thats the route you want to take i honestly dont think its worth it. that is a hell of alot of work for not much gain. if it botherd you that much then maby think out side the box and turn the body around so you have a rear engine defender, you get what ever aproach angle you want then. and there are places/people that will attach/provide brackets for the axles. moving the axle forward wouldnt be a massive job, jim at gigglepin had some adapters made on his old truck that screwed onto the end of his radius arms and alowed a male rose joint to be screwed in the other end of the adapter, this lengthend the radius arm but i belived he moved the mounts back so he kept his wheelbase. if you did the same but diddnt move the mount your axle could be moved a few inches and you may have a solution. im not good with steering angles but(im sure im about to be corrected) surely if you moved things forward the same ammount there wouldnt be too much agro?

more to the point can have your tyres protruding past your bumpers on the road?

there is the KISS solution........ buy some waffle boards

[Deface]

@muddy the 90 in question i have had for 4 years and has mainly been my only car and has been used and abused offroad so all the body work is battered and not worth keeping IMHO plus the engine has issues, the gearbox has been used for my other 90, the bulkhead and doors are rotten and axles are being rebuilt to again go on my other 90, but chassis is good (about the only thing ).

My intension is to eventually compete, but Ive never competed before which is why i am unsure on mods etc. For me building the truck will be as much fun as driving it but at the end of it want a competative truck hence all the approach angle type questions.

Ive had a look through the members vehicle forum at all the challenge truck builds which is where i have got most of my ideas from, but there are a few ideas i have of my own that i need know if they possible or not as the case my be.

[yella 90]

you move the body back 2 inches so you get pleanty of room for 37"+ tyres

[dirtyninety]

Id just start the build on a disco chassis, custom rear end and push the front axle as far forward as possible and have hydraulic steering. simples. If you want to be competitive you would have to completely redesign the 90's suspension and there would still be people with better clearance and COG than you.

just my 2p