I need to play with my 4X again - I've just put it down because I've been experimenting with other toys (Mi6 Evo and Xpress XQ1). The 4X was a blast once the Serpent camp figured the go easy on the heave damper and harder on the roll dampers. Got the latest upgrades on the car but not driven it yet. Will have to give it another go soon

This is more of an intermediate to expert level car so buyer beware. If you don't understand weight transfer then you'll struggle tuning this car. The shock and roll concepts are easy to take on board if you've got a good baseline on set up. That said I find the car is very easy to tune especially with the new parts like the linear links and RRS upgrade which are essentials. I'm not sold on the top deck yet and don't see this as being essential. I'm almost awesomatix quick which is the benchmark chassis in Australia ATM and I'm Way quicker than my previous X-rays .

Yes parts availability is average but you need very little spares to keep on top of the car. It is a bit fiddly to build but once built requires very little maintenance. Getting the diffs out can be a bit painful initially and changing the lower roll centre pills is time consuming but other than those 2 the car is simple to work on. Shocks do require regular rebuilds but bar xray, nearly all shocks on the market leak to some degree. When it only takes 6 or so drops of oil to fill our shocks its a very simple procedure.

I give it 2 thumbs up 😀

It's a shame that quite a few seem to have given up on the car so soon.

Thinking about buying one so I can run older IFS bodies.

It's the same issue again, this can be a car for the masses if there are guides on how to setup and explaining the mindset behind the chosen suspension geometry and other characteristics. If whoever designed this car won't release that info who can reverse engineer one, the average weekend racer?

I haven't honestly had issues with parts availability, other than the new top deck and other newer parts, but here In the US, most if not all parts are in stock most of the time.

Yes I haven't had issues with parts availability. Even all the new parts came through quite quickly. I tend to agree that more info on the cars setup should've been issued by its designer David Ehbar. He did some explanation videos but none were anywhere near detailed enough. That said if you've already got a good grounding on setup theory it doesn't take long to get your head around setting up the 4x. The really nice thing is that the car is sensitive to changes.

I asked in our FB page some detailed geometry questions but didn't get satisfactory answers and David was quiet... Felix says just go with the flow lol

The problem could be the base setup.
We already know that the initial oil/spring/pistons combination is not a success.

My impression is that the roll centers are off the charts compared to the other chassis. With initial setup (3mm) the upper and lower arms are parallel, I've never seen that on any other chassis.

My plan is to put the central aluminum beam and work on the roll center. The problem is not the car it self, it is the balance between the front and the rear.

But for the moment, I'm looking to change the bearings in the rockers by brass bushings so I can have less play (I can make the ground clearance by 1mm without any movement in the shocks, glups)...

Good observation. I sort of eye balled the RC and both front and rear seemed very low. Removing the H bars and thinner shims on inner ball links brought the RCs close to ground.
The car (my first run) was ok with default setup before I removed the H stiffiners on medium grip asphalt and turned pretty well but it suffered wash out on rear on high speed turns while coasting and unpredictable loss of grip in the rear. I removed the H in the front and the rear became more unstable. I didn't have time to try different things other than that. Next time I want to try both H's gone and different oils in roll and heave dampers.

I had the same experience when running outside. The rear end washed out. In modified this is not a good thing. Bought a T4 2017 and lowered my 5 min time with 6s first run. The 4X can be very fast for some in certain situations but also very difficult in other. I feel that the setup window is small, where the car actually works, compared to a more convential touring car. Many people here prefers the Eryx 4.0 outside instead.

Some suggestions for asphalt. I Never run the h blocks, too stiff. Try running 2 or 1mm under the arm mounts front and rear to raise the roll centre. Try running 2/3 mm of caster shims behind the rear top arms, this also creates more rear steer. I'm running 2k2hole orange heave front/ rear and 2k zero hole roll shocks grey or green rear springs andq green or purple front.

There you are!

Unpredictability on the rear off power during hi loads usually means there is a geometry issue (roll centre, alignment, camber gain,etc...).

Now, having parallel front arms is good actually! The rear roll centre just has to be a tick higher.

In my testing outdoors the car is loose at the rear because it is rolling too much to the extent it's rolling off the rear tyre. It needs to be much stiffer in roll. Hence the blank pistons and 2-3k oil in the roll dampers. I'm up to using blues and grey springs in the roll dampers and the car is much better. I don't have the loose rear-end anymore in high speed corners. It just seems the harder I go the better the car gets. Bear in mind I'm running all the latest parts. I'm actually 1mm less shims under the rear upper arm mounts too. The car is getting better every run.

I'm pleased to see that there are some people that agree with me.

By the way, I'm not sure that the RC are too deep in the ground. On my car, lower and upper arms are parallel with 2mm shim. With that, it is geometrically impossible that the RC is in the ground.

A little bit of help by RC Crew Chief would be nice for that.

The lower arms inserts are also buggering me. On my VBC, I have small shims in the rear and nothing in the front. Does anybody already tried to mount the rear arms support middle-up instead of middle-low?

Removing the H is a really bad idea as it will create some flex points. I'm considering using standoffs (from PC motherboard) instead of the H.