Friday, October 23, 2015

Sakura D4: Smoothing Up the Drivetrain and D3 Rear Arm Swap

The D4 has been a solid runner so far, but that doesn't mean I should stop trying to improve on it a bit. Like everyone else, I have been waiting for 3 Racing to finally release their upgrade parts for the D4. I desperately want to replace the plastic steering arms with some aluminum parts. I'll probably try out some of the rear suspension mods that they have coming as well. In the mean time, I did a few mods with some parts that are already available.

The drivetrain is not bad from the factory, but the plastic pulleys never seem to run completely true. I went with some aluminum pulleys to add durability and to help it run extra smooth. I kept with the stock pulley sizes (33T & 16T). While I was at it, I upgraded to the aluminum solid axle from the D3 (SAK-D120/PK) along with the heavy duty outer joints (SAK-09/HD).

I also swapped the rear control arms out with some stock D3 arms that I had laying around. The D3 arms drop right in place, but are shorter by about 2mm. This gives me the option of narrowing the rear track if I need to, or I can run deeper offset wheels in the rear for a better look. The shock mounting positions are slightly different, but still in a range that provides good adjustment when needed.

Obviously, the pink needed to come off the solid axle. The entire drivetrain is smoother now and there is almost zero backlash between the heavy duty outer joints and the CVDs. I was able to notice the difference while driving and feel that it is a mod worth doing.  Stay tuned for more...


  1. Have you thought about swapping to a ball diff? I've been debating this because some of my friends have them in their GRKs and love them.

    1. I haven't really considered using a ball diff. I'm not sure what the point of them is, really, other than being a crutch for a sub-optimal setup/driving style. There is already so little grip back there, and I can see them causing issues and inconsistency with off throttle slides and applying the brake. When it comes time for forward bite (acceleration) you are handicapped there also. Just my $.02

    2. Yeah, from what I understand it makes the car a little smoother? I would guess there is something to them though with the right setup because every drift company makes them. Thanks for you advice.

    3. Can u send me all the pieces I need for that rear conversion I want to do it to my D4 also and remove the plastic factory one

  2. Hi,I know this is an old post but what are the benefits of the shorter rear lower arms on the d4?thanks