About option parts for the XRAY X4! A lot of you have asked what option parts I recommend, and which ones I personally use.

Basically - it really depends on what surface you will be racing on, and what kit version you have decided to get. Last but not least, it depends what you expect to get out of the kit. Are you a serious racer, attending high levels of competition, or do you plan to mostly practice or club race with your car? This will also decide what parts you may be interested in! Please see my detailed notes below for an explanation.


Both carpet & asphalt:
302312 - 3 Dot Caster Inserts - To better be able to fine tune the caster settings of the car (mainly on the rear). We often like to use more rear caster, to make the wheelbase shorter, and to improve initial steering.

305357 - -0.5mm Hexes - Makes the track width narrower, which is beneficial on low to medium grip carpet, and most asphalt tracks.

303768 - Aluminium T-brace. Not as frequently used as on the T4 platform, but still a very good option for fine tuning the flex of the car.

308286, 308276 & 308288. C=2.6, 2.7 and 2.8 springs. Mainly used at the rear of the car, to improve cornering speeds on higher grip conditions. Will often be faster, but more difficult to drive than the kit springs.

305306 & 305408 - ECS 58mm & CVD 54mm BB Driveshafts. Improves cornering speed and drivability compared to the kit shafts. Recommended for competition, and especially on high grip tracks, mainly on the front axle.

304972 & 305138 - ECS & CVD BB Outdrives - Required for your solid axle & rear differential when using BB driveshafts.

293406 - HUDY 293406 2-Hole Clamp Horn - This is my preferred servo horn. It makes the steering more direct, but will also increase the chance of servo damage. Keep in mind that you'll need a specific horn for your type of servo (23, 24 or 25T). I use the 25T version for my Brunorc servo.

309852 - Brass Nickel Coated Weights - These are SUPER trick. They mount directly onto the motor mount, in 3 different spots. Right in the center of the car, so they won't affect your front to rear weight bias.

For asphalt:
302821 & 302822 - Front 1.1 and 1.2mm Anti-Roll Bars - To improve front grip, and to increase roll. Helps to make the car more aggressive when needed. Recommended for asphalt tracks only.

301072 & 301073 - Split Topdecks - Improves overall grip & corner speed for racing on asphalt.
For carpet racing:
301071 - 1.6mm Topdeck - Provides better side traction, and makes the car more aggressive, which is a good match together with either of the aluminium chassis plates.

302823 - Front 1.3mm Anti-Roll Bar - Improves front grip, and allows the car to roll a bit more. Mainly recommended for EU carpet conditions!

303822 - Rear 1.2mm Anti-Roll Bar - Improves rear grip, and allows the car to roll a bit more. Mainly recommended for EU carpet conditions!

306198 - Brass Shorty Weights - For modified racing on small tracks only! To be used together with shorty batteries.


A. Hagberg