[RoelfleRoux]

Macj,

You are almost correct The LWB Blister was only available in a 3.5 quadcam 24v motor, but the SWB featured both the 3.0 12v or the 3.5 24v motor.

Roelf

[macjohnw]

Macj,

You are almost correct The LWB Blister was only available in a 3.5 quadcam 24v motor, but the SWB featured both the 3.0 12v or the 3.5 24v motor.

Roelf

Never to ugly to learn hey?

[4ePikanini]

AFAIK the early gen2 3.0 were 12v SOHC with distributor.

The later ones were 24v DOHC with coilpacks.


....I think....

[Gerrit Loubser]

The blister is a tough little devil and you still have the ladder suspension

Henk, I assume you mean ladder frame chassis?

Structure
The Gen 2 employs a body-on-frame structural concept (i.e. the body is separate from the chassis) whereas the Gen 3 is of unitary construction (i.e. the body and frame are integral). The Gen 3 also employs substantial front and rear subframes to which the front and rear suspension is attached.

The chassis of a body-on-frame vehicle is sometimes referred to as a ladder frame due to the fact that it basically consists of to side members running the length of the vehicle with several cross members connecting them.


Suspension
The Gen 2 has torsion bar sprung independent suspension at the front located by wishbones and a coil sprung beam axle located by two trailing radius arms and a Panhard rod (also called a lateral rod or track bar). The Gen 3 has coil-over-shock front independent suspension located by wishbones and coil sprung independent rear suspension located by multiple links.

By the way, the suspension concept is not determined by the structural concept. For instance, the Jeep XJ Cherokee (built from around 1984 to 2001) as well as the Jeep ZJ Grand Cherokee (built from 1993 to 1998) and WJ Grand Cherokee (built from 1999 until 2004) employed unitary construction, but had beam axles front and rear (coil sprung at the front and leaf or coil sprung at the rear). On the other hand, the Nissan R51 Pathfinder employs body-on-frame construction, but has allround independent suspension.



So which structural concept is best?
Each design choice comes with its own set of advantages and disadvantages.

Some people believe that vehicles with separate chassis are more rugged, quoting the use of this concept in heavy goods vehicles as a supporting argument. This is not really true, though; the fact is that it is possible to design a vehicle of unitary construction that is every bit as rugged as one with a separate chassis (have a look at armoured cars; they are invariably of unitary construction). In heavy goods vehicles the structural concept is dictated by the fact that the cab is actually very small relative to the entire vehicle (so it would not make much sense to integrate it with the chassis) and because the vehicle suspension is designed to carry heavy loads and is therefore stiffly sprung, the cab often needs to be isolated from the rest of the vehicle in the interest of ride comfort.

The Gen 3 has often been accused of being inferior in terms of structural integrity due to the unitary construction concept, but I have never seen any proper scientific proof to back up these allegations. In fact, there is quite some evidence to the contrary (e.g. this thread).

The unitary construction concept has the following advantages:
* It is possible to lower the vehicle center of gravity, which has safety benefits (in terms of handling and roll over resistance)
* It is possible to achieve much better space utilization due to greater freedom in placing components
* It is possible to achieve greater bodyshell rigidity, which has benefits in terms of refinement
* It is possible to achieve lower total mass for a given structural strength
* It is possible to achieve lower total cost
* It is possible to achieve greater occupant protection in the case of an accident, because of the flexibility in creating crumple zones.
...
and the following disadvantages:
* It is much more difficult to isolate the occupants from road noise, as the load introduction points of the suspension are practically attached to the passenger compartment
* Rust can be a much more serious issue than on a body-on-frame vehicle, as the basic structure is of relatively thin gauge material.
* Load introduction points (e.g. towbar mounting points, jacking points, suspension mounting points, et.c) need to be considered and designed carefully in order to distribute the loads adequately
* Repairing a vehicle of unitary construction that has been involved in a serious accident can be more difficult than with body-on-frame construction.


The body-on-frame structural concept has the following advantages that I could think of:
* It is possible to achieve good sound and vibration isolation for the passenger compartment, as it is separated from the chassis by polymeric body mounts
* One has much greater freedom in designing load introduction points, as the chassis is generally made from heavy gauge metal and is less prone to damage due to localized load introduction.
* Accident repair can be simpler
* Corrosion can be a less serious concern, because of the much thicker gauge steel used for the actual structural member: the separate frame
* The same basic chassis can be used for several different models or updates of the same model, thus limiting the scope and hence cost of development projects
...
and the following disadvantages:
* Center of gravity is most likely to be higher
* Mass is likely to be higher
* Cost is likely to be higher
* Less opportunity to optimize space utilization
* Lower torsional rigidity leading to somewhat compromised on-road handling
* Poorer occupant protection due to less effective crumple zones



Independent suspension or beam axles?

Once again, there are pros and cons both ways. Here are some that I could think of:

Independent suspension advantages:
* Better ride quality and handling characteristics, due to lower unsprung weight and the fact that the motion of each wheel is not affected greatly by motion at other wheels
* Additional packaging flexibility, because there is no beam connecting the wheels that has to be accommodated and cleared, even with the suspension at full bump travel
* Wheel toe and camber can be varied in response to the loads on the axle in order to ensure optimal camber angles or to achieve things such as passive rear steering
* Wheel toe and camber and caster can be adjusted relatively easily

...
Independent suspension disadvantages:
* More expensive
* More joints that can wear and would have to be maintained
* Ground clearance under axle center changes depending on the load carried by the axle (unless complications such as self leveling air suspension are introduced)
* Wheel camber angles might change depending on the load carried by the axle (unless complications such as self leveling air suspension are introduced)
* Ground clearance under axle center is reduced by wheel deflection to conform to terrain
* Wheel travel is limited by sideshaft angle considerations
* Heavier than a beam axle setup for the same strength/durability



Beam axle suspension advantages:
* Simplicity and often fewer moving parts
* Cheaper manufacturing cost
* Lighter overall vehicle weight (Easy to make strong and robust).
* Ground clearance under the axle is not affected by the load that the axle carries
* Ground clearance under the center of the axle increases if any wheel is deflected upwards to travel over an obstacle
* Wheel camber angles are not affected by the load carried

Beam axle suspension disadvantages:
* Poor ride quality due to high unsprung mass (differential, axle housings and all of the sideshaft mass as well as part of the propshaft mass is part of the unsprung mass)
* Wheel toe and camber angles are not variable as a function of suspension deflection
* Castor and camber angles are not readily adjustable and toe angles can only be set on steering axles.


Just as a parting shot, it is worth noting that while many believe beam axles to automatically allow greater suspension flex (in order to conform to terrain that tends to cross-axle the vehicle) than an independent suspension setup, but when comparing the Gen 2 with the Gen 3, one finds that the flex is remarkably similar on both. In the case of the Gen 3 the flex is slightly more balanced between the front and the rear, because its coil-over-shock front suspension is a little more supple than the Gen 2's torsion bar system while its independent rear end is at a slight disadvantage compared to the Gen 2's beam axle.

The fact is, though, that neither of the cars are that good at cross axle flexing. In the case of the Gen 2 this is partially to be blamed on the dual trailing arms that are pinned to the rear axle housing by two rubber bushes each. In order for the axle to roll relative to the chassis, these bushes have to be deformed. For small angles of roll, the roll stiffness is quite low, but this rises rapidly as the roll angle increases. This rapidly increasing roll stiffness effectively limits the flex of the Gen 2 as the vehicle tends to rather lift a wheel than flex the suspension in many situations. The Gen 2's two natural competitors (the Isuzu Trooper and Series 90 Land Cruiser Prado) both had multi link rear suspensions that had very low roll stiffness allowing them to quite dramatically outflex the Gen 2.

[4ePikanini]

Another outstanding post

[HBannink]

Quite right in your assumption Gerrit, and a brilliant explanation.

I have been out with both and for the stuff I do no difference worth mentioning, what I have noticed is a difference in the suspension. I have been with a friend with a lwb blister and my OME out performed his standard suspension, I doubt that I am so much better a driver so I must put it down to the suspension
As you mentioned it is a lot easier to mount after market bits like rock sliders and such but it is not impossible on the gen3 one just needs a bit more ingenuity.

littleman I would go for the full OME and not mix and match. Suspensions are not referred to a suspension systems for no reason. It is pricey but well worth it in my book.

[littleman]

Thanks so much for the very informative responses. I think that I have more or less made up my mind to keep my blister and go for the OME upgrade option. Mine is the 3.0 Gls 24v. As mentioned the bottom end seems to have enough grunt but the top end is a bit lazy and that I was considering putting in one of those after market chips to improve this aspect. The people in George reckon that if a 20% improvement is achieved then 80% of this achievement will go towards improving fuel consumption and 20% towards power improvement. The reason for this is apparently because an increase in fuel consumption under normal circumstances is more important than an increase in power that is mainly require when 4x4ing. Maybe they have a good point but I am not yet sure if the 20% claimed improvement is at the lower end or top end.If anybody has any experience or advise to offer I will be grateful.
Anyway guys thanks so much once again for all the comments, suggestions and advice given. Much appreciated.