I am raising it as I own a cottage in the middle of nowhere in Exmoor, and with he current setup, it's a tad lower than I'd like at a few points. Grip is my main issue on the tyres I am running, and to run the meaty tyres I have bought - I simply wouldn't have enough room on the standard setup. One of the rear shocks needed replacing anyway, and for £250 for the new shocks, springs, tyres and wheels I really couldn't go wrong.
Visually it is quite obvious that these springs are a fair bit bigger than the standard springs - so I am struggling to understand your point in how this won't raise the truck?
Surely if I am 2" higher, then I will have 2" more to compress when off-road than if I was on a 2" lower setup? I know it may not be a true 2" lift, but it sure as hell looks higher.
Its a 300tdi '95 5 door.
Ok, so here goes...
A spring is not a shock and a shock is not a spring
A spring may well lift a vehicle, but a shock never will. I assumed you probably fitted lift springs as well, although you hadn't mentioned this.
As for off road.
1. I'd actually be surprised if a stock Disco isn't more than fine for the use you are describing. But that's by the by.
2. A stock Disco actually uses the same length springs, shocks and axle movement as a stock Defender does. This means it rides pretty heigh in standard trim. Higher than almost all other production 4x4's....
3. The things that make this appear less on a Disco are:
a) The long front and rear over hangs
b) A bigger body with smaller wheel arches (meaning less gap between the tyre and the arch)
c) Stock Disco's normally run 28-29" tall tyres. So from the hub to the ground is generally less than on a Defender, which will normally run 31-32" tyres.
3. A 235/85R16 is a standard fitment tyre for a Defender. This means if you fit them to a Disco you'll get the same sort of ground clearance as a stock Defender. Which frankly, unless you are doing extreme off roads events, is more than sufficient for almost any other off road use. You still have the longer overhangs to deal with however.
The stumbling block is, the body is usually in the way to fit the bigger tyres.
4. So the answer is to move the body out of the way a bit. There are lots of ways of doing this.
a) My preferred route, trim the arches. This means it keeps everything else stock and retains all the good design parts with no compromises.
b) A body lift. This is where you lift the body up from the frame. Often a cheap way to lift a vehicle, but can be a PITA to fit. And sometimes looks a little odd.
c) A suspension lift. Which will lift the entire vehicle up. This is the most common choice and probably the most compromised.
5. Most suspension lifts are done by fitting a HD (heavy duty) spring. At rest they don't compress as much and give you the lift. The trouble is, a stiff spring will ride like crap on the road. And off road will be less compliant and will want to resist flex and articulation.
6. Many HD springs are also short, so they don't extend well, so off road fall out of the upper spring seat. Meaning you need to solve this new issue. And are often lead to the belief that you are getting more travel.
7. Longer shocks can give you more down travel, but you really need a suitable spring to make the most of this. And stock upper mounts can actually reduce travel. Also with HD springs what you may find is, the vehicle will want to lift a wheel more readily.
8. Ultimately this means the majority of lifted Disco's actually perform worse off AND on road than a standard vehicle. Which is really quite an achievement.
9. A suspension lift will also change the pinion angles of the props and may cause binding.
10. A suspension lift also changes the caster angle of the front hubs, which can make the steering wooly and will highlight and exaggerate knackered steering components.
Now I'm not saying don't do this. But it is well understanding the changes you are making, what effect they will have and if they are actually going to meet your needs or not.
My personal preference is to keep a vehicle riding as low as possible. This keep the CoG low and the vehicle more stable. Then trim the body to get the tyres to fit. As for suspension, you want it compliant for the task at hand and want to retain up travel as well as down travel.
As for rims. A 235 will fit on a 6.5 - 8J rim comfortably. Depending on the exact tyre and how you want them to sit on the rims. Off road it is often good to go for a narrower rim to get a square or bulging side wall, as this will offer the rim additional protection. A wide rim might give a somewhat 'stretched' look.
As for offset, it will depend on the rim in question. A 6.5 and an 8j rim with the same offset will result in the inner and outer edges of the rim being in different places.
Steering lock is limited by the tyre hitting the radius arm, rim that moves the tyre more out bound will help here. But you quickly will find the tyres will stick out of the arches.
A 235/85R16 will foul the front bumper end caps and maybe even the front bumper. So you'll need to solve this in one way or another. It might clear better with the lift, but off road under compression you may find yourself with issues.
At the rear you'll need to trim the rear of the rear arch. This is known as the Camel Cut.... because it will hit the tyre under compression. Wider and bigger offset rims more so.
To this end, you may even want to run different offset rims front to rear.
