Two weeks in, building an SD 3.0, stuck on the spacers

The full text is short. The poster names the chassis as the SD 3.0 Competition, says they are currently building it, says they do not understand using a diff spacer to change angle, and mentions two weeks of drifting with an RMX before this car.

What the post does not give is everything a specific answer would need. It does not say which spacers the manual step refers to, or where in the build they sit. It does not say whether "angle" here means steering angle or something else in the instructions. It does not name a surface, a tyre, a gyro, a motor or a target track, and there is no follow-up comment in the material confirming any of it.

So nobody reading it cold can tell the builder which spacer to fit. What a reply can do is ask the right four questions, and point at the one document that settles it.

Yokomo prints the answer, and it is in the Competition's own supplement rather than the main instruction manual. The SD3.0 Competition comes with a supplement whose steering block page replaces step 15 of the standard SD3.0 manual, and on that page (page 8 of the supplement) spacers are how the front geometry is set:

• One set of spacers sets the trail. With no spacer the trail is +1.0 mm, and each 0.5 mm of spacer takes 0.5 mm off it, down to −2.0 mm with 3.0 mm of spacer.
• Another sets the kingpin angle. With no spacer it is about 1°, and each 0.5 mm adds about a degree, to about 7° with 3.0 mm.

Yokomo adds one caveat under the tables: the numbers differ if the height of the ball stud is changed. Both sides are built the same way.

So "diff spacer to change angle" most likely means different spacers to change the kingpin angle, rather than anything to do with the differential. The standard SD3.0 manual's step 15 installs the steering block without these tables; the Competition's steering block is what adds them.

The instruction manual, the Competition supplement and Yokomo's blank setting sheet are all in RTFM, on the SD3.0 Competition's page, with Yokomo's own copies first.

If you are answering this thread, these are the details that turn the manual's tables into an answer for this car:

• Which of the two tables the step means. The page has one for trail and one for kingpin angle. "Angle" points at the second, but a photo of the page the builder is on settles it.
• Whether the ball studs are where the manual puts them. Yokomo's own note: change the ball stud height and the numbers in both tables change too.
• Surface and tyre. Carpet, P-tile, polished concrete and asphalt are different configurations, and the spec tyre at the track the car will run on changes what a sensible starting setup looks like.
• Whether the car is being built to a published baseline. A first chassis is easier to learn on when it is assembled to the maker's own default and changed one item at a time afterwards.

For a driver two weeks into the hobby, the most valuable reply is not an exotic setting. It is confirmation of what the kit's default configuration is, so the car gets finished, run, and then adjusted from a known state.

The post is Help!! Yokomo sd 3.0 competition on r/rcdrift, posted by u/Traditional-Unit530 on 26 September 2026. If you own the same kit and have the manual in front of you, that page number is the reply worth writing.