SUSPENSION IMPROVEMENT FOR THE ZD RACING EX16

One thing you'll notice about the pro version of the ZD Racing EX16 is that it has these beautiful small scale aluminium oil filled shocks, they look amazing. Sadly whoever assembles the ZD racing cars has led them down badly because the suspension is set up poorly from the factory. It can however easily be fixed and I'll show you just how to do that in this guide

This is the third of a 3 part series of tuning guides for the ZD Racing EX16. The others can be found here:

• ​THROTTLE AND STEERING SENSITIVITY IMPROVEMENT FOR THE ZD RACING EX16 (AND OTHER CARS)
• DRIVELINE FIX FOR THE ZD RACING EX16

I'll address 3 suspension fixes in this article: Filling the shocks with oil, suspension geometry and droop screws. Read on!

Correcting the oil level in the shocks

As I said in the into, the shocks on this car are beautiful, especially at this scale. It is an absolute tragedy then they they put barely any oil in them!

First remove the shock from the car - 2mm hex at the top, philips at the bottom. I do one at a time so I don't mix them up (just in case)

Next remove the spring retainer at the bottom plus the spring and small black plastic collar. The collar is quite hard to remove due to the short travel of the shaft you'll find a way

The top caps are screwed down HARD. I had to use a vice and some pliers to get mine off

After removing the cap and diapragm, you'll see how much oil they don't have. Mine were about 30% filled only.

I always use 30wt silicon shock oil as a start point for suspension, feels about right here. Fill up to near the top 

Getting the right oil level is hard, especially in short travel shocks like these. move the piston up so the ring is about 2-3mm from the top of the chamber and hold there. Add the rubber diapragm and screw down the cap while still holding the piston.

Once the cap is on tight move the piston up and down. If you cant move it then there is too much fluid - try the previous step again. There should be consistent resistance all the way up and down. You may have a few bubbles, that is ok and hard do avoid in these shocks

Reinstall and repeat for the other 4.

These shocks came with a ridiculously low oil level that provided no dampening. With this corrected as per above the dampening is much better meaning the car should have better traction expecially over imperfections on the road surface during cornering. A much needed improvement that hopefully ZD racing improves on. Check the dampening now below:

Adjust the geometry

I'm not going to get stuck into suspension geometry here - the topic is vast. What I have shown below is an option to improve the travel and performance of the rear (IMO)

Remove the top screw with a 2mm hex drive

Reinstall in the innermost hole on the suspension tower. This will allow greater travel that is softer and better suited to this small an light RC Car. This is set up correctly on the front.

Adjust the droop screws

Droop screws provide an adjustable stop point for suspension extension and in doing so provide a reliable ground clearance. I'm really please that this car not only has that provision but even includes the grub screws, they just need adjusting. For a strictly road car I like to set a ride height where the drive shafts are roughly parallel with the ground, maybe a touch lower.

Use a long 1.5mm hex driver to access the grub screw. Above are the ones on the front. Turn clockwise to decrease ground clearance and anticlockwise to decrease. Do this off the ground to take springs out of the equation

Repeat for the rear, make sure you get front the back and left to right as even as you can.

Test the balance by lifting the car off the ground with battery out. Place the front wheels down then gently lower the rear and check if both wheels touch the ground at the same time. If not see which wheel is too low by eye and adjust to suit. You can see above my left rear is touching the ground before the right - the droop screw on the rear left needs tightening a little.

You can obviously make these measurements more sophisticated but this should be fine for this type of car.

Conclusion

Suspension is set up poorly from the factory and so making these changes yields a significant improvement in handling. Once you have the basics done as shown here, you can then adjust to suit you own needs.

​I ordered my ZD Racing EX16 From Banggood. They have a regular version and a pro version. I ordered the pro which is better out of the box (with the best wheels!) and is much better for tuning and upgrading. My full review is coming soon

If you are looking for a discount on this car, I will post any coupon codes or flash sales for it over here on my coupons and discounts page. Remember buying from any of these links supports my page without any cost to you and is appreciated especially since I don't ask for money via patreon and the like. If you want to get involved in this discussion, feel free to join the QuadifyRC Facebook Group Here or like my page below