1987 90 Lift & tyres

[Legionnaire]

I am wanting to put a 2" lift on my 90 and new tyres. What lift kit is recommended and what tyres. The 90 is mainly used for off roading. What problems am i likely to come accross ie I saw one yesterday which looked good until it went off road and the articulation caused the tyres to catch the bodywork.

Any advise gratefully received.

[datalas]

Oooh, that's a complicated question, and has been much discussed before :)

short summation of what has gone before....

1.  Suspension is a jolly complicated subject, with many pople having firmly held opinions which they will argue long into the night about, and thats *before* you take into account the "I've just spent the best part of two grand on it" syndrome which will further strengthen that opinion right or wrong.

2.  Increasing articulation isn't that usefull unless you also get elongated bump stops as you're in danger of binding the coils up (squishing them), this will cracker your springs up in no time, unless you get the springs custom made and spend a couple of hours and a maths degree working out the numbers (as muddyweb did)

3.  Anything above +2.5" is pushing your luck, probably.  Depending on how tall you are, and whether the SO is willing to climb into the vehicle.

4. You should really do something to castor correct the steering, this can be done by buying new castor corrected radius arms for the front, otherwise on road handling will be degraded and you'll end up with really weird results.  Offset bushes to fix the castor aren't a particularly great idea as they tend to mess up the articulation, they are however cheaper.

5.  You'll need longer shocks too.

6.  Don't mention the words "dislocation" and "good" in the same sentence unless you want to be dragged into an argument.

7.  Don't mention tyres either.

8.  If you must mention tyres, be aware that very few people will declare that the tyres they just spent hundreds of pounds on are poo.  Also be aware that there is no such thing as a general purpose tyre, and also no general purpose off road tyre.  Unless you're going down the "one set of tyres for each type of terrain" road then you *will* have to accept a comprimise.  Which tyre you get should therefore be based upon the type of terrain  you think you're most freuqently going to find yourself on.  Choose from the following, sand, snow, mud, bog, clay, tarmac.   Each type of terrain requires a different type of tyre, and their performance outside of their designated terrain will vary between poor, and godawful.

9.  You can spend a *lot* of money on suspension and tyres, and you should really work out why you're doing it before you spend anything.  Be aware that simply lifting the suspension doesn't always mean you can put bigger wheels on, lifting it and elongating the bump stops should do however.  

10. Be aware that really putting bigger wheels on just lifts your diff off the floor.

11.  Also be aware that there are at least two camps in the war of the dislocation.  One camp believes it to be useless, but will buy dislocation cones because they're fed up of having to put springs back in when they pop out.  The other camp believe it's the best thing since sliced bread.  Both camps however tend to agree that you need a locking diff in the back before it would help.  This adds around a grand to the percieved price...

As for personal opinion.  The ninety that Muddyweb is building for my will end up with a procomp +2" lift, and es9000 gas shocks.   It will also get elongated bump stops (as soon as I remember to buy them) and probably end up on ~32" BFG Mud Terrains.

I think that's it,  I'm sure I've missed something but Muddyweb will undoubtedly be back later and tell me where I'm wrong.

[Legionnaire]

The reason I am wishing to do this is just to give me more ground clearance under the diffs, If I just went for larger tyres and wheels what would be the largest wheels/tyres I could put on without the lift because this would surely also lift the bodywork,  most of my offroading is in mud.

Thanks

[datalas]

Well, as you've spotted putting bigger tyres on does indeed lift both the diff *and* the bodywork away from the floor..  it does however mean that your bodywork is closer to your tyres as they have this annoying habit of being the same radius on the top as the bottom (unless you get some really weird ones I guess ;) )

Personally I'd be wary of putting anything much bigger than a 7.50R16 (stupid new fangled equivalent someone please?) on an unmodified 90, since even on the leafer I used to scrape the rear wheel arches when playing.

Be warned though, one thing that I forgot to mention.  Bigger tyres will hamper your turning circle because they will end up fouling on the chassis.

As for driving on mud, be aware that there are two sorts of "mud" and two sorts of tyre to drive in them.  One sort (of which the simex is the most commonly drooled over example) is essentially designed to dig its way through the mud until it finds a more grippy surface, this works well in a lot of cases as the top layers of mud tend to be the squidgy ones, then you end up in denser packed mud with rocks in it.  This tactic doesn't work well in a lot of the scottish bottomless bogs, since the nearest solid thing in those cases is australia, and regardless of tyre size you're likely to run out of ground clearence before you find it.  This would mean that diggy tyres will leave you bogged upto your axles in no time.    They also do the same in sand.

The other design of mud tyres are best described as either "big paddles" or "tractor tyres", and are designed to gain traction by displacement, that is to say to move as much of the mud infront of the tyre to the back of it.  Thus you essentially doggy paddle your way through the mud.

This is a little more effective than digging *if* you're in the wetter bottomless pits, but again isn't perfect in all situations,  in loose and reasonably dry mud with a hard base they take a lot more effort to get anwhere, and will tend to loose traction when they get to the harder stuff underneath as they are less chunky and grippy than the digging ones.

Sand tyres, and Floatation (bog) tyres are what you would expect, they're designed to have the maximum amount of rubber in contact with the floor at any time, thus spreading the weight of the vehicle and hopefully stopping it sinking.  This is why road tyres are better in sand than simex.. go figure ;)

[Eeyore]

Well, I think our Daz has covered most bases!

For a recommendation, I like the Procomp conversion as the shocks are brilliant. If you can afford custom springs, it would save losing an inch of upward travel, but you have to ensure you have the same number of coils or less than the standard spring (assuming similar wire diameter) to prevent the things getting coil bound under full compression.

OME stuff also seems to carry a good reputation, but some don't like the ride it provides, particulalrly for high articulation off road work. But as I've never used it I can't provide a definitive answer.

If you lift, fit dislocation cones, because you never know when a spring will pop out unintentioanlly (DeCarbons for instance have more travel than the standard shock, even though they are the same length and this has caught folk out in the past).

Any other discussions re: forcing dislocation will be resolved by the usual two falls, two submissions, or a knock out  :lol:  

And as for tyres, well, it's your can of worms and you opened it!

.......but I run BFG MTs <ducks>.

HTH
Eeyore

[Legionnaire]

Thanks for all the advise. I am weighing everything up and it looks a nightmare.

I am going to put on a Scorpion 2" lift with dislocation cones and hope the prop will still work and not have to be replaced. I am going to put mt tyres on and probably run on two sets, one for off road and one for normal use.

My current insurance company will not insure it but I have found others that will.

Tyre size, I am currently on 205R16, If i put on something larger I suspect it will throw out the speedo, will anything else be affected? Scorpion recommend 285/75 16 or 255/85 16, what problems am I likely to have if any.

Please advise.
Thanks

[Legionnaire]

Decision Taken and parts ordered:

200 TDI Discovery Dual rated springs

2" pro comp shockers, Dislocation cones and 7.5 R16 mud terrain tyres.

Andrew