Everyone seems to think that they are Robby Gordon or whatever with deep pockets.
Not me... my parents are still alive.
[Is it to soon ?... maybe its to soon. Aussie humor thing.]
A sad thing, That family has done alot for motorsport over a very long time. R.I.P #bajabob.
The only real special tool you need is the safety needle to manage the gas charge.
Or drill it and fit a valve set while its apart if you can fit the nipple sticking out.
To get the total performance out of set of shocks, any set of shocks, they need to be tuned to YOUR vehicle and YOUR butt.
This is where adjustment comes in for easy tuning, and going in a direction. [CDC for its lack of line pressure on fast bumps helps ALOT]
In my opinion, the 80 series suffers from a few issues in the suspension....
#1, Limited uptravel, especially on the rear suspension. The rear suspension has 1.5" less uptravel than the rear suspension with the frame level. Most 80s sit a little stink-bug to help this. If you want to go fast, lifting the vehicle and then install bumpstop spacers is not the right path. It won't matter what shock you have if you only have 3-4" of uptravel out of the suspension. You need that axle to have time to slow down. More uptravel, as long as overall height is kept in check, will be good. 50/50 travel out of the shock is a good place to start, but I think better things might start to happen as the travel bias moves towards more uptravel vs downtravel.
This is where our slinky kit works on 5.5" up travel, out of 12" stroke, with the 1 1/4" bump spacer factored in, whis is pretty close to 50/50.
Built in hydro bump zone in the last 40mm up travel helps slow it down ALOT at fast piston speed.
The problem with lack of down travel in a cruiser means lifted wheels, even cornering, and that means chewed tyres, shifts in weight, lack of traction. The rear really needs as much down travel as it can.
#2, Bumpstops. The rear inner bumpstops are basically designed to be an overload spring. They are stiff and seem to cause kick issues on the rear suspension, especially with limited uptravel.
We normally remove those, and on heavier trucks run air bags in the coils for light to heavy load, or heavy tow bar weight too, but they work well as a shorter option no spacer to become part of the spring rate on compression on a heavier truck. I have also run these in the front coils in 80s, to have some adjustable spring rate, handy for tuning with different spring rates on the spot sometimes too.
The front bumpstops are also pretty stiff and long. The front axle will actually compress in the chassis till the metal on the bumpstop cup contacts the lower spring mount without binding. That means that the stiff front bumpstops are engaged for at least 2.5-3" of suspension uptravel!
From the Aug 92 update we got chassis bump stops on our 80s as the coil towers were bending badly just running the inner rubber stop, so for us they come in contact with about 40mm of up travel and we cant bottom them out.
This is what happens without the chassis bump stops on early models. [From memory the USA get the bump stop bracket from bottom to join to coil tower to hold it against chassis with holes to bolt the bump stop on, just no bump stop * see bottom pic]
And this with no inner chassis double plate.
This is SNOWY set up so 96 with the plate on, but no rubber bump stop on it. [yes, had weld the panhard bracket on LHD too for cracks]
#3. Springs. Not many 80-series coils maintain any preload at full droop. You want preload. You only want enough spring rate to hold up the vehicle at the height you want with that preload you need. There are some packaging limitations on the 80 series if the springs where to have those features. We are starting to see more dual rate coils that basically block out the soft section of the coil to help this. The stiff part of the coil is a balance for overall vehicle weight.
Its why we went tapered wire [more block height room] and dual rate tunable by the length, taper from one rate to another.
Our pre load at full droop shocks bolted in is between 120 and 160 lb front and rear, depending on intermediate or heavy coil.
Enough to allow wheel movement while crawling on tippy toes, without transferring that movement into the vehicle to induce momentum.
I'm currently building a hybrid so I don't think too much of what I end up doing on the suspension will carry over, but the theory stays the same. I'm at a point where the stock LX450 springs, especially the rear, will likely be too heavy a rate and give too much lift! The total vehicle weight I will be dealing with will likely be about 4000lbs to 4500lbs loaded for a trip with people/gear/fuel.
Arent they all just hybrids of a standard truck
I think at 4000-4500, half of what we are really talking about with a loaded fitted out 80, that 2.5s with the extra size and capacity of oil, and surface area make alot of sense, if your saying 2.0s work well at the weight your building for.
And #4, I think is very valid is the rear lower arms being straight chassis to diff means roll steer when trying to improve handling. We went heavy sway bar for rear bar, wheel carrier / long range tank set ups to prevent roll, and hence steer from the rear, but the only ways to solve that are the easier, make the lower arms 250-300m longer for a larger arc of movement, and /or move the front mounts outward to change the operating angle.
Like Toyota did with the 100 when it went to IFS, once they got a pointy front end set up, they had to work on roll steer from the rear, so tapered the arms to help with this. When you get the right front set up in an 80 where it also becomes pointy [goes where you point it, when you point it there] roll steer in the rear becomes alot more obvious, especially with rear weight.
