RCK Ch. - Senden

I spent a few evenings making sure my lovely XRAY X4 2026 was up to the tried and tested 5P standard: Because perfect preparation prevents poor performance.

This last weekend I spent my time at the nice little track of Indoor-Racing-Senden, near Ulm. It's permanent with ETS carpet but rather high traction and a layout that does favour a … more assertive driving style.

High grip, fast locals, full send always … nothing like a little challenge to dust of one's fingers, right?

The Tech Report Section

My car was completely kit standard apart from titanium screws.

Initial Setup: I already started with raised rear rollcenter to 2.5mm. I also went to 0.5mm / 1mm under the wheelhubs for some more rollcenter staggering.

To compensate for the different rear wishbone angle I raised the rear inner camberlink ballstuds to 1.5mm to make the geometry look right.

I spent Saturday getting to know the tires and motor as used at the RCK challenge which are slightly different and less powerful than the ETS combo.

While doing that I tested my way through the Team Cayote speedo I used for the first time this past weekend - and really liked it!

Good changes: Lowering the shock angle (first to 2mm f/r, then 1f/2r, then 1f/1r and then back to 1f/2r) made the car easier to drive on Saturday where traction roll was a real thing.

Playing around with bumpsteer and toe-gain shims proved to be quite the influence and changed the ‘required alertness' of the driver dramatically especially in the first 3-5 laps. Bumpsteer especially is a great balancing tool to find your perfect spot between steering aggression and a car that remains 'free' mid corner.

I also did play with the shock tower mounting screws and while I prefer the flex characteristics of the vertical screws, I find them to occasionally move slightly.

For racing I then went to the horizontal mounting screws connecting the shock mount to the bulkhead. What was instantly noticeable was how much the front bulkheads flexed together when the car was at ride height (had to raise it by .4mm to be back at 5mm). This was without the bulkhead brace - with it, the difference is not that huge but still noticeable.

I have to re-test this on another track to figure out which version I prefer in the end.

In the end the weekend was too short, and I ran out of test runs, but ended the race with a well handling car that would do the 7-minute finals easily - so now there's only the driver to fix - easy.
Power was great all weekend and even though we did run 7 minutes, I still stuck with the incredibly low Cayote 5300 batteries. To be able to back to back test different battery configurations, I had brass weights mounted under the battery. With the 5300 one I used 50g under the battery, with the 6300 I used 35g, with the 6800 it would have been 0g - balance neutral and well prepared.

Oh, and a very far forward Twister Speciale is still my bodyshell of choice. You can really trust the car to do exactly what you need it to do every single lap.

I have ordered a Ghibli 3 though as I have been hearing great things about it. Maybe that is the new winner?

TL/DR - finished 5th, car was amazing, reduce steering lock for bigger tracks and have fun.