Building and tuning the Double X4 buggy

       

Richard Taylor is one of the most experienced off road racers in Europe and the UK today, His racing career covers in excess of 15 years, during which time he has Competed at all levels from Club to World Championships.
During this career he has won multiple British National off-road championships in both 2 and 4 wheel drive as well as countless European Podiums!

Building Tips.

When building the gearbox don't fully tighten the fixing screws; instead
just back them off a little and this will help make the gearbox spin more freely.
Also put a little of the White thrust race grease on the gears this will also reduce wear and increase efficiency.

With the rear kick up shims cut one side out of the screw hole so you don't have to take the screw fully out to change them instead you can just slide them in and out, this will make adjustments to the rear a lot easier.

Put some oil on the shock cartridge o-rings before inserting the shock shaft, and also only insert the shaft from the piston end. This will help to stop any damage being done to the seals.
After fitting the shock cap and seals to the shock shaft, measure the length of each shock shaft with the ball joint on and then adjust them so that both the front shafts and the rear shafts are the same length as each other before you finally assemble the shocks.
To help free up the bearings try soaking them in motor cleaner and spinning them on a shaft to remove excess grease, that is used in the manufacturing. Then re-oil them with some light bearing oil.

Another tip to make the bearings run even freer you can remove the inside (the non-visible when fitted in the car) shield. Make sure you leave the shield on the side that is exposed, it helps keep dirt out and increases
the life of the bearings.

Although the build quality is very good it is always worth checking that no
shims are needed in any of the wishbones etc. to remove any sloop.
Another simple tip is to pre-tap the threads into the plastic carefully, this will help to make sure you do not snap a screw or strip the head.
Racing Tips.

Tuning Tips

Understeer.


1) Shorten the front camber link.
2) Lower front camber link.
3) Raise the outside of the front camber link on the caster block.
4) Move the batteries forward.
5)Shorten the rear camber link on the shock tower.
6) If the understeer is on the way in, decrease front rake/kick up this will load up the front on deceleration into the corner.
7) If on the way out, increase the front camber for more steering out of the corner, this will also give less into the corner.



Oversteer.

1) Lengthen the front camber link.
2) Raise front camber link.
3) Lower the outside of the front camber link on the caster block.
4) Move the batteries back.
5) Lengthen the rear camber link on the shock tower.
6) If the oversteer is on the way in, increase front rake/kick up this will lessen the load on the front on deceleration into the corner.
7) If on the way out, decrease the front camber for less steering out of the corner, this will also give more into the corner.


Bad on the rough:

1) Lengthen the wheelbase.
If the car is grounding out badly try:
1) Harder springs.
2) Thicker oils.
3) Increase the pack i.e. go from an orange piston to a red piston (smaller piston holes = more pack). If this makes the car feel too stiff in roll, you can at the same time lower the weight of the oil, by 5 to 10 weight, this will still make the car stiffer initially but still have a soft feel once moving.
Raise the car slightly.If the car is bouncing of the bumps or not riding them:
1) Softer springs.
2) lighter oils.
3) Decrease the pack i.e. go from an orange piston to a blue piston (bigger piston holes = less pack). If this makes the car feel too soft in roll, you can at the same time increase the weight of the oil, by 5 to 10 weight, this will still make the car feel softer initially but will still have a stiffer feel once moving.
4) Increase the rear squat if the car is kicking up.

Poor rear traction.

1) Put less rear squat on the car.
2) Move the batteries back.
3) Decrease the pack i.e. go from an orange piston to a blue piston (bigger piston holes = less pack). If this makes the car feel to soft in roll, you can at the same time increase the weight of the oil, by 5 to 10 weight, this will still make the car feel softer initially but will still have a stiffer feel once moving.
4) Make the rear camber link longer on the shock tower.
5) Loosen the slipper clutch if it is just wheel spinning.

Helger Racing