Sakura D4: New Dampers, Aluminum Parts, New Gyro, and New Screws

I've really been enjoying the D4 so far, and the more I work with it, the more I like it. 3 Racing made a nice step forward over the D3 and now that factory upgrades are starting to filter through the pipeline, essential upgrades can be completed.

The first order of business is taking care of my main gripe with the stock chassis... steering wipers.

While it can slide nice with the stock plastic bits, there is a lot of flex in the wipers. I chose to use the 3 Racing factory aluminum steering to upgrade mine. The parts are nicely made, but do have one flaw. The wiper plates that screw to the bearing pivots have threading in the holes where the screws go through to fasten them to the pivots. The threads at those locations need to be drilled with a 3mm drill. Don't drill any of the other threaded holes, as they are all needed. Everything fits perfectly in place, and removes all flex from the steering.

I also upgraded to a D-Like premium gyro. It is money well spent. After battling with gyros that drift off center and behave erratically, this thing is a godsend. The smoothness + control is noticeable, and rock solid.

The next upgrade is in the dampers department. I chose to try some new M's pistons, shafts, and lower seals, along with some TRF main bodies for this build.

These parts are very nice, but be warned that many of the components are very small, and there are some very thin shims that are used to make it all work well. Assembly and setup can be a little tedious, but the end result is worth the effort.

I went with the 3-hole 1.0mm pistons, and the +2mm shafts. A little more droop never hurts. Ultimately I ended up drilling the rear shock pistons out to 1.15mm and used 10wt oil. The fronts stayed at 1.0mm and I used 30wt oil for them. A TRF foam insert was used over the front bladders but not in the rear, to promote weight transfer to the rear.

The end result is an incredibly smooth damper with almost zero stiction. I am really happy with these things, and the improved control is noticeable.

Sticking with the silver/black theme that this chassis has going, I decided to replace all the factory fasteners with stainless screws. Nobody makes a kit that I have found, so I put together one for myself. I definitely like the look.

Currently, the car is driving fantastic. It has a reasonably wide speed envelope, has great off throttle control, transitions smoothly, and can be driven easily to adjust line. All great characteristics IMHO, but I still keep working to improve it. Future upgrades include aluminum suspension mounting blocks along with some aluminum rear suspension arms. I also have the upcoming Usukani gear drive conversion, front bulkhead, and rear lower roll center mounts on order. They should be released very soon. Expect a detailed overview once they arrive.

Some chassis shots in the current state of tune: